SL2048 Manual RevF

1

SkyLane SL-2048L-Band or 70 MHz Satellite Modem

With FFT Technology, and ReedSolomon/Turbo Codec and Ethernet Data

Interface Options

INSTALLATION AND OPERATIONSMANUAL

Rev F

Visit our WEB site at www.advantechamt.com

Head Office U.S. Office European OfficeSPL/ACT Wireless Inc. SPL/ACT Wireless U.S., Inc. SPL/ACT Wireless Europe Ltd.657 Orly Avenue 4710 E. Elwood Street 4A Edison RoadDorval, Quebec Suite 14 St. Ives, HuntingtonH9P 1G1 Phoenix, AZ, 85040 Cambridgeshire, PE27 3LFTel : 1 (514) 420 0045 Tel : (480) 784 4646 Tel : 44 1480 357 600Fax : 1 (514) 420 0073 Fax : (480) 784 1010 Fax : 44 1480 357 601

An Advantech AMTTM CompanyAn Advantech AMTTM Company

PREFACE 3

SkyLaneTM SL-2048 Modem O&M ManualAn Advantech AMTTM Company

PREFACE

Thank you for purchasing the industry’s first L-band digital satellite modem with FFT technology,the optional Reed Solomon and Turbo codecs and the optional Ethernet interface. Thisdocument describes the installation, operation, and maintenance of the SkyLane SL-2048satellite modem. It has been the goal of SPL/ACT Wireless to provide you with a product andthe associated documentation that eases the installation and operation, and provides longevityof this modem into a fully operational satellite network.

The following information provides the document part number, revision, the copyright notices,along with the pertinent FCC, English, German, and French compliance, and the serviceabilityof the modem.

Document Part Number and Revision:

Revision History: Date Document RevisionJune 2000 Initial ReleaseNov 2001 Rev BApr 2002 Rev CJune 2002 Rev DJune 2002 Rev E As per ECO # 3155

July 2002 Rev F As per ECO # 3247

Copyright Notices:

Copyright 2002 by SPL/ACT Wireless, Inc., an Advantech AMT Company. All rights reserved.This manual may not be reproduced or disclosed in whole or in part by any means without thewritten consent of SPL/ACT Wireless, Inc.

FCC Warning:This equipment generates, uses and can radiate radio frequency energy, and if not installed inaccordance with the instructions contained herein, may cause interference to radiocommunications. It has been tested and found to comply with the limits for a Class A computingdevice pursuant to Subpart J of Part 15 of the Federal Communications Commission rules,which are designed to provide reasonable protection against such interference when operatingin a commercial environment. Operation of this equipment in a residential area is likely to causeinterference; in which case, at the user’s expense, is required to take whatever measures arenecessary to correct the interference.

If radio frequency interference is encountered after the installation of this equipment, necessarycorrective measures are required to reduce this interference. Information on recommendedmeasures can be obtained from the manufacturer.

4 PREFACE


English/German/French Warnings:

English Text (UL/CSA) German Text (VDE/TUV) French Text

WARNING WARNUNG AVERTISSEMENTOnly a qualified technicianshall make access to theinterior of this unit.

Der Zugang ins Innere desGerätes ist nur einemfachlich qualifiziertenTechniker gestattet.

Seul un spécialiste devraitavoir accès à l’appareil.

1. To ensure adequatecooling of the equipment, a2.0-inch unobstructedspace must be providedaround all sides of the unit.

1. Um die Kühlung desGerätes nicht zubeeinträchtigen, ist esnotwendig, an allen Seitendes Gerätes ca. 5 cm Raumzu lassen.

1. Afin de ne pas nuire auprocessus derefroidissement, il estnécessaire de laisser unespace d’environ 5 cm dechaque côté de l’appareil.

2. The AC Power Socketshall be installed near theequipment and shall beeasily accessible.

2. Stellen Sie das Gerät inder Nähe eines geerdetenSchutzkontaktsteckers soauf, dass der Stecker leichterreichbar und zugänglich ist.

2. Placez l’appareil prèsd’une prise de courantfacilement accessible.

WARNING WARNUNG AVERTISSEMENTRemove power plug fromthe power socket beforeperforming any servicework on the unit!

Vorm Öffnen des Gerätesmuss der Netzstecker vomStromnetz getrennt werden!

Débranchez l’appareilavant de l’ouvrir.

Caution:

Service of this unit can only be made by factory authorised service personnel. Failure toobserve this warning can result in malfunction to the unit as well as electrocution to personnel.

Avertissement:

Cet appareil ne peut être examiné ou réparé que par un employé autorisé du fabricant. Si cetteconsigne n’est pas respectée, il y a risque de panne et d’électrocution.

Vorsich:

Dieses Gerät darf nur durch das bevollmächtigte Kundendienstpersonal der fabrikinstandgehalten werden. Die Nichtbeachtung dieser Vorschrift kann zu Fehlfunktionen desGerätes führen und das Personal durch Stromschläge gefährden.

Notice:

All specifications, tolerances and product characteristics are subject to change without notice.

Format of Manual:

This manual is arranged in Sections and Appendices. The beginning of the manual states theWarranty and Service support of the product. There are currently 4 Sections to the manual, asnoted below:

Section Number TitleSECTION 1. OVERVIEWSECTION 2 INSTALLATIONSECTION 3 OPERATIONSECTION 4 BENCH TESTING THE SL-2048

PREFACE 5


Appendices are provided to complement the use of the product, such as when the modem isused with other products, or embellishment of a modem feature or an optional feature, such asthe optional receive buffer. There are currently 4 Appendices as follows:

Appendix Letter TitleAPPENDIX A. CABLES AND PINOUTSAPPENDIX B. S/N AND Eb/No VALUESAPPENDIX C. RECEIVE BUFFER CARD OPTIONAPPENDIX D. SL-2048 OPERATION WITH SIERRACOM BUC AND

ADVANTECH SSPB

The page number in the Table of Contents (following) hyperlinks to the actual page where aSection or Paragraph is located. Should you have an electronic copy of this manual, merelyplacing the cursor over the page number and clicking on it brings up the page to the locationwhere the Section or Paragraph is located. (The cursor turns into a hand when it is directly overthe page number.)

6 PREFACE


“This page is intentionally left blank”

TABLE OF CONTENTS 7


TABLE OF CONTENTS

PREFACE .................................................................................................................... 3Document Part Number and Revision.................................................................................................3Copyright Notices ................................................................................................................................3FCC Warning.......................................................................................................................................3English/German/French Warnings ......................................................................................................4Caution ................................................................................................................................................4Avertissement......................................................................................................................................4Vorsich.................................................................................................................................................4Notice ..................................................................................................................................................4Format of Manual ................................................................................................................................4

TABLE OF CONTENTS............................................................................................... 7

LIST OF FIGURES....................................................................................................... 9

LIST OF TABLES ...................................................................................................... 10

WARRANTY AND SERVICE..................................................................................... 11WARRANTY ........................................................................................................................................ 11

Extended Warranty Options ..............................................................................................................11SERVICE ............................................................................................................................................. 11

SECTION 1. OVERVIEW .......................................................................................... 131.0 INTRODUCTION ......................................................................................................................... 131.1 PRODUCT OVERVIEW .............................................................................................................. 131.2 CONNECTOR PANEL ................................................................................................................ 141.3 CONFIGURATIONS .................................................................................................................... 151.4 TECHNICAL SPECIFICATIONS................................................................................................. 17

SECTION 2. INSTALLATION ................................................................................... 192.0 INTRODUCTION ......................................................................................................................... 192.1 UNPACKING AND INSPECTION ............................................................................................... 19

2.1.1 Unpacking.............................................................................................................................192.1.2 Inventory ...............................................................................................................................19

2.2 INSTALLATION CONSIDERATIONS......................................................................................... 192.2.1 Site Considerations...............................................................................................................192.2.2 Power Requirements ............................................................................................................192.2.3 Link Budget Analysis ............................................................................................................20

2.3 INSTALLATION .......................................................................................................................... 212.3.1 Modem Rear Support ...........................................................................................................222.3.2 Data Connections .................................................................................................................232.3.3 BUC and LNB/BDC Connections .........................................................................................232.3.4 Front Panel Controls and Indicators .....................................................................................242.3.5 Transmit Levels ....................................................................................................................262.3.6 Bringing the Modulator Online ..............................................................................................272.3.7 Translation from L-Band to Transmit/Receive Bands...........................................................27

8 TABLE OF CONTENTS


SECTION 3. OPERATION ........................................................................................ 293.0 INTRODUCTION ......................................................................................................................... 293.1 REMOTE MONITOR AND CONTROL FUNCTIONS ................................................................. 30

3.1.1 RS-232 Rear Panel Remote M&C........................................................................................313.1.2 RS-485 Rear Panel Remote M&C........................................................................................313.1.3 Simplified User Interface.......................................................................................................313.1.4 Display Configuration (Modulator Only)................................................................................323.1.5 Display Status (Modulator Only)...........................................................................................32

3.2 MODULATOR (TRANSMIT) COMMANDS................................................................................. 333.2.1 Transmit Control Commands................................................................................................333.2.2 Modulator Operation for PowerTrack Option........................................................................363.2.3 Modulator Test Modes.........................................................................................................373.2.4 Transmit Monitor Commands ...............................................................................................38

3.3 DEMODULATOR (RECEIVE) COMMANDS .............................................................................. 393.3.1 Receive Control Commands.................................................................................................403.3.2 Demodulators Equipped with 70 MHz IF Inputs ...................................................................423.3.3 Commands for Dual Demodulators ......................................................................................423.3.4 Receive Monitor Commands ................................................................................................443.3.5 Monitor Commands for Dual Demodulators .........................................................................453.3.6 Carrier Acquisition ................................................................................................................453.3.7 Carrier Frequency Configuration ..........................................................................................453.3.8 Measuring Acquisition Time of the SL-2048 Demodulator ...................................................47

3.4 MODEMS WITH REED SOLOMON OPTION............................................................................. 483.4.1 Transmit Commands/Status with R/S Option.......................................................................493.4.2 Receive Commands/Status with R/S Option........................................................................503.4.3 Receive Buffer Commands/Status for R/S and Turbo Options ............................................51

3.5 MODEMS WITH TURBO OPTION.............................................................................................. 533.5.1 Transmit Commands/Status with Turbo Option ...................................................................533.5.2 Receive Commands/Status with Turbo Option ....................................................................54

3.6 MODEMS WITH ETHERNET BRIDGE OPTION ........................................................................ 553.6.1 Wan Controller......................................................................................................................55

3.7 PRESET COMMANDS................................................................................................................ 563.7.1 Building PRESET Commands ..............................................................................................563.7.2 Saving PRESET Configuration Commands .........................................................................573.7.3 Viewing PRESET Configuration Commands........................................................................573.7.4 Activating PRESET Configuration Commands.....................................................................57

3.8 MONITORING CHASSIS STATUS............................................................................................. 573.8.1 Monitor Commands ..............................................................................................................573.8.2 RS-485 Addressing Mode.....................................................................................................58

SECTION 4. BENCH TESTING THE SL-2048 ......................................................... 594.0 TESTING METHODS .................................................................................................................. 59

4.1 Testing One SL-2048................................................................................................................594.2 Testing Two SL-2048s..............................................................................................................59

APPENDIX A. CABLES AND PINOUTS .................................................................. 61A.1 RS-442/449 TO RS-530 ADAPTER CABLE............................................................................ 61A.2 RS-442/449 TO RS-530 Y-CABLE........................................................................................... 61A.3 RS-530 DATA INTERFACE PINOUT....................................................................................... 62A.4 RJ-45 ETHERNET CONNECTOR PINOUT ............................................................................. 63A.5 RS-232 CONNECTOR PINOUT ............................................................................................... 63A.6 RS-232 NULL MODEM CABLE ASSEMBLY .......................................................................... 64A.7 RS-485 CONNECTOR PINOUT ............................................................................................... 64A.8 RJ-11 TO 9-PIN ADAPTER CABLE ........................................................................................ 64

TABLE OF CONTENTS 9


A.9 BUC/MODEM CABLING REQUIREMENTS ............................................................................ 65A.10 L-BAND TRANSMIT CABLE ................................................................................................... 65A.11 L-BAND RECEIVE CABLE ...................................................................................................... 65

APPENDIX B. S/N AND Eb/N0 VALUES .................................................................. 67

APPENDIX C. RECEIVE BUFFER CARD OPTION ................................................. 69C.1 FUNCTIONAL DESCRIPTION ................................................................................................. 69C.2 SIMPLIFIED THEORY OF OPERATION ................................................................................. 70C.3 BUFFER COMMANDS AND STATUS..................................................................................... 71

C.3.1 Receive Buffer Commands...................................................................................................72C.3.2 Receive Buffer Status ...........................................................................................................72C.3.3 Receive Buffer Standard Configuration Settings..................................................................72

APPENDIX D. SL-2048 OPERATION WITH SIERRACOM BUC AND ADVANTECH SSPB..... 73D.1 BUC INTERFACE CONNECTIONS ......................................................................................... 73D.2 LNB INTERFACE CONNECTIONS ......................................................................................... 73D.3 RS-232 M&C INTERFACE CONNECTIONS ........................................................................... 73D.4 SL-2048 MODEM CONFIGURATION ...................................................................................... 73D.5 TX CARRIER ENABLE ............................................................................................................ 73D.6 RX CARRIER ACQUISITION ................................................................................................... 74

APPENDIX E. COMMANDS NO LONGER SUPPORTED BY THE DEMODULATOR.............. 75

LIST OF FIGURES

Figure Title Page

1.1 Front View, SL-2048 Satellite Modem ……………………………. 131.2 SL-2048 Rear Connector Panel (3 Versions)………………………. 141.3 SL-2048 Label…………………………………………………………. 162.1 SL-2048 Rear Support Kit Installation 222.2 Typical SkyLane SL-2048 Interconnection…………………………. 242.3 Exploded View of Front Panel LEDs and M&C RJ-11 Jack………. 252.4 Hand-Held Terminal…………………………………………………… 252.5 Power Loss in LMR-600 Cable versus Cable Length and

Frequency……………………………………………………………… 263.1 SkyLane SL-2048 Transmit Clocking Options……………………... 383.2 Simplified Block Diagram Showing Reed Solomon Option Card… 483.3 Preferred Transmit Clocking Options……………………………….. 523.4 Preferred Receive Clocking Options………………………………… 533.5 Switches for Filtering and Control…………………………………… 56A.1 RJ-45 Connector Showing Pinout…………………………………… 63A.2 RJ-11 Connector Showing Pinout…………………………………… 65C.1 Simplified Logic Diagram of Enhanced Receive Buffer…………… 71D.1 Test Diagram 1………………………………………………………… 74

10 TABLE OF CONTENTS


LIST OF TABLES

Table Title Page

1.1 SkyLane SL-2048 Models……………………………………………. 151.2 Technical Specifications………………………………………………. 172.1 Allocated Bandwidth for each Carrier Type…………………………. 212.2 Front Panel LED Indicators…………………………………………... 253.1 SL-2048 Standard (L-Band or 70 MHz) Configurations…………… 293.2 SL-2048 Additional Settings when Equipped with Reed Solomon. 303.3 SL-2048 Additional Settings when Equipped with Turbo…………. 304.1 SL-2048 Back-to-Back Parameter Configuration………………….. 594.2 RS-530 Loopback Connector………………………………………… 60A.1 RS-422/RS-449 to RS-530 Adapter Cable Pinout…………………. 61A.2 RS-422/RS-449 to RS-530 Y-Cable Pinout………………………… 61A.3 TX/RX Data Pinout……………………………………………………. 62A.4 RJ-45 Connector Pinout……………………………………………… 63A.5 RS-232 Connector Pinout……………………………………………. 63A.6 RS-232 Null Cable Connector Pinout…………………………….…. 64A.7 RS-485 Connector Pinout…………………………………………….. 64A.8 RJ-11 to 9-Pin Connector Cable Pinout…………………………….. 64A.9 Cable Assembly Pinout for SL-2048 Modem and SierraCom

Ku Band BUC…………………………………………………………... 65B.1 S/N and Eb/No Values…………………………………………………. 67C.1 Buffer Depth Options using Alternate IDT FIFO Devices…………. 69

WARRANTY AND SERVICE 11


WARRANTY AND SERVICE

WARRANTYSPL/ ACT Wireless, Inc., warrants to Purchaser that the Products and any Repaired Products (Repairs)will be free from defects in material and workmanship for a period of two years from the date ofshipment to Purchaser.

SPL/ACT Wireless' obligation under this warranty is limited to replacing or repairing, at SPL/ACTWireless' option, Products or Repairs found by SPL/ACT Wireless to be defective within the warrantyperiod. All such replacements and repairs shall be performed at facilities designated by SPL/ACTWireless and shall be performed only after the customer has received a Return Material Authorisation(RMA) number from SPL/ACT Wireless and has returned the Product to SPL/ACT Wireless, shippingand insurance prepaid by Purchaser.

The returned Product must be accompanied by the customer's name, address and telephone number,the model and serial number of the Product, a statement of the purchase date and a detaileddescription of the problem. Products and Repairs returned by Purchaser shall be repaired by SPL/ACTWireless using new or refurbished parts and shall be returned to Purchaser by SPL/ACT Wireless,shipping prepaid by SPL/ACT Wireless.

This warranty shall immediately become null and void if, in SPL/ACT Wireless' sole judgement, theProduct has been subject to unauthorised modification, misuse, abuse, neglect, accident, improperinstallation or application, alteration or neglect in use, storage, transportation or handling, or if the serialnumber and/or other Product markings have been removed, defaced or altered.

SPL/ACT Wireless may, at its discretion, perform out of warranty repairs at SPL/ACT Wireless'customary charges or enter into a written agreement extending the terms of this warranty at a pricestated in such agreement. All repairs performed out of warranty or pursuant to an extended warrantyagreement shall be subject to all of the applicable limitations and procedures of this Agreement.

The above warranties are in lieu of all other warranties, expressed, implied, or statutory or arising bycustom of trade usage, including any warranty of merchantability of fitness for any unique, special orexpress purpose, and of all other obligations of liabilities whether in contract, tort or otherwiseincluding, without limitation, liability for damages (whether general or special, direct or indirect,consequential, incidental, exemplary) or any claim for the loss of profits or business or for damage togoodwill.

Extended Warranty OptionsPlease contact Customer Service or your reseller for information on optional extended warranties.

SERVICESupport functions provided by SPL/ACT Wireless' Customer Service include complete factory repair forboth in-warranty and out-of-warranty equipment.

In the U.S.A., call SPL/ACT Wireless' Customer Service at 1-480-784-4646. In Canada, call SPL/ACTWireless, Advantech AMT at 1-514-420-0045. In Europe, contact SPL/ACT Wireless at 011-44-122342037 and ask for Customer Service. In all other countries, contact your local SPL/ACT Wirelessdistributor or reseller.

A Customer Service engineer will answer warranty-related questions, discuss your specific equipmentproblems, and when necessary, give you shipping instructions for returning equipment to SPL/ACTWireless for repair.

12 WARRANTY AND SERVICE


To return a Product for service or repair, you must obtain a RMA number from SPL/ACT Wireless'Customer Service. The following information is required:

•••• Customer name, address, telephone number

• Model number

• Serial number

• Detailed description of problem

All customer-returned units must be shipped to SPL/ACT Wireless freight prepaid, in the original cartonor equivalent. SPL/ACT Wireless is not responsible for damage in transit. All repairs will require returnof the entire equipment to SPL/ACT Wireless. No individual modules will be accepted for repair underthis contract.

SECTION 1. OVERVIEW 13


SECTION 1. OVERVIEW

1.0 INTRODUCTIONThis section provides an overview of theSPL/ACT Wireless’ SkyLane SL-2048 SatelliteModem. It is a versatile rack-mounted productdesigned to be used in a Single-Channel-Per-Carrier (SCPC), Multiple-Channel-Per-Carrier(MCPC), or even a Multiple-Address-Per-Carrier(MAPC) environment using a Frame Relayapproach. A front panel view of the product isshown in Figure 1.1.

1.1 PRODUCT OVERVIEWSkyLane SL-2048 is the satellite industry’s first standalone L-Band modem with FFT Technology.Through the use of innovative L-band technology, SkyLane eliminates the need for a conventional RFindoor unit, and reduces by more than 50% the cost of a RF transceiver (RFT). A RF transceiver canrepresent more than half of the overall costs of an integrated VSAT Solution. SkyLane can be used asa standalone satellite modem and works with any voice/data multiplexer.

Two methods of acquiring the satellite carrier are deployed in the SL-2048 modem. One methodutilises the more conventional sweep function, and the other utilises the Fast Fourier Transform (FFT)algorithm. FFT Technology reduces the lockup time when acquiring the carrier for the first time.Acquisition times of <500 milliseconds for a 32 kbps data rate carrier over a +24 kHz frequencyuncertainty are achievable. (See Carrier Acquisition of Table 1.2, Specifications.)

Standard features of the SL-2048 include:

• L-Band IF output of 950-1450 MHz, input of 950-2050 MHz tuneable in 100 Hz steps• Provides DC power and 10 MHz reference for Low Noise Block Down Converter

(LNB)/Block Down Converter (BDC) and Block Up Converter (BUC)• Variable data rates from 9.6 to 3,850 KBPS, in 1 BPS increments• Viterbi (FEC), ½, ¾, or 7/8 symbol rate• BPSK/QPSK modulation• Programmable Acquisition Range• FFT Technology for fast acquisition applications• Occupies 1 Rack Unit (RU) of Rack Space (1.75”)• Consumes less than 60 Watts of Power (not including BUC power supply)• Full Monitor and Control Capability using a Hand-Held Terminal (option), ASCII terminal,

or PCOptional features of the SL-2048 include:

• Receive buffer with enhanced clocking options and programmable digital loopbackcapability (See Appendix C)

• Reed Solomon codec concatenated with Viterbi plus Doppler buffer• Turbo standalone codec (¾ rate) plus Doppler buffer• V.35 Interface (includes cable adapter to comply with 34-pin Winchester connector)• RS-422/RS449 interface (includes cable adapter to comply with 37-pin D connector)• Ethernet 10Base T interface (similar to RAD TinyBridgeTM) with RJ45 connector• 70 +18 MHz IF interface• Dual demodulator• Transmit only, receive only, or receive only with dual demodulator versions• Various RF input and output connector types

Figure 1.1. Front View, SL-2048Satellite Modem

14 SECTION 1. OVERVIEW


• 48 VDC input power• BUC power supply voltages and currentsControl of the SL-2048 modem includes an RJ-11 (6-wire telephone plug) on the front panel for easyconnection to an ASCII terminal using an asynchronous RS-232 interface. It also includes a rear panelRS-232 and an RS-485 serial bus interface. The ASCII terminal can be a hand-held terminal or a PCwith terminal emulation software. User-friendly, menu-driven resident software is stored in non-volatileRandom-Access-Memory (NV-RAM). Once configured, the modem retains the last memory settings,and retrieves those settings upon power restoration.

Data interface to and from the modem is a synchronous RS-530 interface (25-pin D connector).Through the use of interface cables, the data port can be converted to a synchronous RS449/422interface (37-pin D connector) or a V.35 interface (34-pin Winchester connector).

The data interface can also be optionally equipped to interface directly to Ethernet 10BaseT (10 MHz)systems. The connector for this option is a RJ45 female connector. The Ethernet port is similar to theRAD TinyBridgeTM. It can operate in the full duplex mode, simplex mode or the half-duplex mode.

The standard SL-2048 is powered from a universal power supply with a range from 96 to 263 VAC,47-63 Hz, producing a maximum of 50 Watts. The modem utilises only 25 Watts; the extra is reservedfor LNB/BDC power (20 VDC, 0.5 Amperes). The standard BUC power supply produces 24 VDC at amaximum of 3.5 Amperes (110 Watts), which is in addition to the 50-Watt power supply. Optionally,the BUC power supply can be upgraded to 48 VDC, 2.2 Amperes. SPL/ACT Wireless does notrecommend higher current options, since the residual power left inside the modem can cause insidetemperatures to rise beyond our current specifications.

1.2 CONNECTOR PANELThe SL-2048 is configured as a transmit/receive modem. It can also be powered from a plus or minus48 VDC supply. Figures 1.2 (a), (b) and (c) show three different configurations.

The (a) version is a fully configured modulator/demodulator, with the option of providing DC power and10 MHz reference to the BUC and LNB/BDC. The (b) version is powered from a 48 VDC source, whichcan be either -48 VDC or +48 VDC. The (c) version is AC powered, as shown in (a), but with theoptional 10BaseT Ethernet interface.

Figure 1.2. SL-2048 Rear Connector Panel (3 Versions)

(a). Modem, Standard Version, AC Input

(b). Modem, 48 VDC Version, with BNC Input

(c). Modem, Standard Version, AC Input, with Optional Ethernet Data Port

IF Output to BUCL-Band 50 Ohms SW1

BUCPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms

IF Input From LNBL-band 75 Ohms

T3, 15A 230V

J5 P1Caution:

Double-pole/neutral fusing

100-240 V50-60 Hz115V-2.5A 60Hz230V-0.7A 50Hz

TX/RX DATARS-530


BUCPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


J5P1

FUSE

+ -+ + + +

48 V1.5 A

T6, 3A 250V

TX/RX DATARS-530


BUCPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


T3, 15A 230V

J5 P1Caution:


100-240 V50-60 Hz115V-2.5A 60Hz230V-0.7A 50Hz

(a). Modem, Standard Version, AC Input

(b). Modem, 48 VDC Version, with BNC Input

(c). Modem, Standard Version, AC Input, with Optional Ethernet Data Port


BUCPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


T3, 15A 230V

J5 P1Caution:


100-240 V50-60 Hz115V-2.5A 60Hz230V-0.7A 50Hz


BUCPower

SW1

BUCPower

SW2

LNBPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


T3, 15A 230VT3, 15A 230V

J5 P1Caution:


100-240 V50-60 Hz115V-2.5A 60Hz230V-0.7A 50Hz

TX/RX DATARS-530


BUCPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


J5P1

FUSE

+ -+ + + +

48 V1.5 A

T6, 3A 250V

TX/RX DATARS-530


BUCPower

SW1

BUCPower

SW2

LNBPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


J5P1

FUSEFUSE

+ -+ + + ++ + + +

48 V1.5 A

T6, 3A 250VT6, 3A 250V

TX/RX DATARS-530


BUCPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


T3, 15A 230V

J5 P1Caution:


100-240 V50-60 Hz115V-2.5A 60Hz230V-0.7A 50Hz

TX/RX DATARS-530


BUCPower

SW1

BUCPower

SW2

LNBPower

SW2

LNBPower

IF OutputTo Demod

70 MHz50 Ohms


T3, 15A 230VT3, 15A 230V

J5 P1Caution:


100-240 V50-60 Hz115V-2.5A 60Hz230V-0.7A 50Hz



1.3 CONFIGURATIONSThe SkyLane SL-2048 modem is available in several models. Use Table 1.1 to verify that you havereceived the correct model for your installation.

All models are identical in appearance. Caution should be taken to insure that the correct modemmodel is used when DC power is applied to the Block Up-Converter (BUC). The label on the top of themodem, centred and near the front panel (see Figure 1.3) provides the Model Number, Part Number,Revision Number, and the Serial Number.

Table 1.1. SkyLane SL-2048 Models

SL-2048

120-CTRDOS-BPX*

OPTION "T"TX FREQUENCY MHz NOTE

1 NO TX

2 70 +/- 18

3 950 -1450 5

4 950 - 1525 1

5 950 - 1750 1

OPTION "O"OPTION CARD NOTE

1 NO OPTION 5

2 BUFFER 4

3REED SOLOMON &

BUFFER4

4 TURBO & BUFFER 4

OPTION "P"DATA INTERFACE NOTE

R 85-265 VAC 5

S -48 VDC

OPTION "C"CHASSIS NOTE

AFULL DUPLEX/

SINGLE DEMODULATOR5

B FULL DUPLEX/DUAL DEMODULATOR

C TX ONLY/MODULATOR

D RX ONLY/SINGLE DEMODULATOR

E RX ONLY/DUAL DEMODULATOR

OPTION "D"DATA INTERFACE NOTE

K RS-230/ RS-422 (25-PIN D) 5

L ETHERNET 10 BASE (RJ-45)

M V.35 1

OPTION "B"BUC POWER SUPPLY NOTE

1 NO BUC POWER SUPPLY

2 24 VDC (4.0 A)

3 48 VDC (2.2 A) 5

4 48 VDC (3.2 A) 1

NOTE

1 NO RX

2 70 +/- 18

3 950 -1450 2

4 950 - 2050 5

5 950 - 2150 1

OPTION "S"SPECIAL OPTION NOTE

0 NO OPTION 3,5

P N-TYPE RX CONNECTOR

Q ACTIVE FRONT PANEL

Notes:

OPTION "R"RX FREQUENCY MHz

1 - option under development (contract review required)2 - option retired - not available3 - "0" is for no option selected4 - option available with Chassis Option "A" & "C" only5 - option in "Italic" type are for Standard Modems with no options

*- for C, T, R, D, O, S, B, P see option tables; last digit of part number "X" is to identify release



Figure.1.3 SL-2048 Label

Ser ial NoModel No

SPLACT



1.4 TECHNICAL SPECIFICATIONSTable 1.2 is a list of specifications for the SkyLane SL-2048 modem.

Table 1.2. Technical Specifications

DESCRIPTION SPECIFICATIONGENERAL Data Rate 9.6 to 3,850 kbps, variable in 1 bps increments

Data Interface RS-530 with RS-422 format

Optional V.35 with cable adapter for 34-pin Winchester

Optional RS-422/449 with cable adapter for 37-pin D

Optional 10BaseT Ethernet (similar to RAD TinyBridgeTM)

Data Connector 25-pin D, female, standard

RJ45 for Ethernet option

Data Scrambling CCITT

IESS-308/309

V.35

Off

Data Clock Source Selectable, Data Communications Equipment (DCE) or DataTerminal Equipment (DTE)

Modulation Schemes BPSK, ½ rate: 9.6 to 1100 kbps, in 1 bps increments

BPSK, ¾ rate: 14.4 to 1650 kbps, in 1 bps increments

QPSK, ½ rate: 19.2 to 2200 kbps, in 1 bps increments

QPSK, ¾ rate: 28.8 to 3300 kbps, in 1 bps increments

QPSK, 7/8 rate: 33.6 to 3850 kbps, in 1 bps increments

Forward Error Correction Rate ½, ¾ and 7/8 convolutional encoding

Viterbi, K=7, Soft Decision decoding

Optional Reed Solomon outer with Viterbi inner codec

Optional Turbo @ ¾ rate

MODULATOR Output Frequency 950 to 1450 MHz, variable in 100 Hz steps

Optional 70 +18 MHz in 1 Hz steps

Output Power Range: -5 to -49 dBm, adjustable in 0.10 dB increments

Accuracy: ± 1.0 dB

Stability: ± 0.5 dB

Outdoor Equipment Reference (through IF output connector)

BUC: 10 MHz, 0 dBm, ± 2 dB

Phase Noise (bandwidth at 1 Hz):-140 dBc/Hz maximum at 1 kHz

-143 dBc/Hz maximum at 10 kHz-143 dBc/Hz maximum at 100 kHz

Outdoor BUC Power (through IF output connector)

BUC DC Power: +24 VDC; 4.0 Amperes maximum

Optional BUC DC Power: +48 VDC; 2.2 Amperes maximum

Output Connector Type N, female; BNC female for 70 MHz version

Impedance: 50 Ohms

Return Loss: >15 dB

DEMODULATOR Input Frequency 950 to 2050 MHz, variable in 100 Hz steps

Optional 70 +18 MHz in 1 Hz steps

Input Connector Type F female; BNC female for 70 MHz versions

Impedance: 75 Ohms; 50 Ohms for 70 MHz versions

Return Loss: >9 dB

Input Level with Automatic Gain Control (AGC)

-70 dBm to -40 dBm, (L-Band mode)

-55 dBm to -35 dBm, (70 MHz mode)



DESCRIPTION SPECIFICATION Outdoor Equipment Reference (through IF input connector)

LNB/BDC: 10 MHz, 0 dBm, ± 2dB

Phase Noise (bandwidth at 1 Hz):

-140 dBc/Hz maximum at 1 kHz



Outdoor LNB/BDC Power (through IF input connector)

LNB/BDC: +20 VDC, 0.4 Amperes maximum

Sweep Range Variable in 1 kHz steps over a range of 1 to 512 kHz

Carrier Acquisition (FFT Mode) Varies, depending on data rate, frequency uncertainty, andoperating Eb/No. The following are some samples of lock timesgiven the data rate, frequency uncertainty, and Eb/No values:

< 1.0 sec @ 19.2 kbps, +24 kHz sweep range, > 8 dB Eb/No.

< 0.5 sec @ 32 kbps, +24 kHz sweep range, > 8 dB Eb/No.

Shorter lockup times can be achieved using a shorter sweep range.

Eb/No Performance, Viterbi Only

1 x 10-5

1 x 10-6

1 x 10-7

1 x 10-8

½ Rate

5.1 dB

6.1 dB

6.7 dB

7.2 dB

¾ Rate

6.2 dB

7.6 dB

8.3 dB

8.8 dB

Rate

8.0 dB

8.7 dB

9.4 dB

10.3 dB

Eb/No Performance, Viterbi + R/S

1 x 10-5

1 x 10-6

1 x 10-7

1 x 10-8

½ Rate

4.1 dB

4.3 dB

4.4 dB

4.6 dB

¾ Rate

5.5 dB

5.7 dB

5.9 dB

6.2 dB

Rate

6.5 dB

6.7 dB

6.9 dB

7.1 dB

Eb/No Performance, Turbo

1 x 10-5

1 x 10-6

1 x 10-7

1 x 10-8

¾ Rate

3.8 dB

3.9 dB

4.1 dB

4.3 dB

Receive Buffer (Option)Programmable. See Appendix C for details. Buffer is included withReed Solomon and Turbo Codec options.

Programmable Loopback (standard with Receive buffer option)

Digitally loops back receive data to transmit data, a test condition.

GENERAL SPECIFICATIONS Monitoring and Control (M&C) Hand-help terminal: RS-232, 9600 bps

External M&C interface: RS-232, RS-485

Commands: ASCII

Configuration parameter storage: NVRAM

Physical Dimensions The SL-2048 is packaged in a rack-mountable 1U EIA chassis.Height: 4.4 cm (1.75")Width: 43.2 cm (17")Depth: 45.7 cm (18")Weight: 11 lb. (5 kg) maximum

Power, AC Autosensing 95-265 VAC, 50/60 Hz

Power dissipation: 25 Watts without BUC power supply; 50 Wattswhen powering LNB/BDC; 150 Watts when powering BUC andLNB/BDC.

Power, DC (Option) 48 VDC, (+ 32 to +72 VDC)

Power dissipation: 25 Watts without BUC power supply, 50 Wattswhen powering LNB/BDC

BUC power supply limited to 24 VDC @ 3.5 Amperes.

Power dissipation with BUC P/S: 150 Watts maximum

Environmental Operating temperature: 0°C to 40°C (32°F to 104°F)Storage temperature: -25oC to 85oC (-13oF to 185oF)Relative humidity: up to 90% non-condensing, operating; up to95% non-condensing, storageAltitude: Up to 10,000’ (3,045 Meters) operating; to 40,000’(12,180 Meters) during transit

SECTION 2. INSTALLATION 19


SECTION 2. INSTALLATION2.0 INTRODUCTIONThis section describes the unpacking, inspection, and installation considerations. All SkyLane SL-2048modems provide a modulator and demodulator connection for interface to a satellite outdoor unit(RFT). A data port connection is used for connection to the aggregate port of a multiplexed, networkmultiplexer, digital video equipment, or other such devices. Additional ports are provided for monitorand control.

2.1 UNPACKING AND INSPECTIONCheck for damage to the outside and the inside of the shipping container. If any damage is noted,contact SPL/ACT Wireless Customer Service and the shipping carrier to report damage.

2.1.1 UnpackingTo insure safety and proper operation of this equipment, use the following unpacking and repackagingguidelines:

1. The equipment is shipped in a high-quality cardboard container and packed with high-densitymolded foam. This type of packing material can withstand impairments such as vibration andimpact associated with long-distance shipment. The original SPL/ACT Wireless packing box andfoam is the only suitable type of packing that should be used for shipping the equipment.

2. While unpacking, observe how the equipment is packed. In order to avoid damage, it must berepackaged in exactly the same manner if you need to ship the unit to another location or return itto the factory. The packing consists of one large cardboard box, two foam side caps, and oneaccessory box. Please retain these items for future use.

2.1.2 InventoryTake inventory of the complete package to ensure that all necessary parts are present. In addition tothe modem, the box should contain a power cord and this manual. A quick review of yourpre-installation site survey form, purchase order, and shipping list should reveal any discrepancies.

2.2 INSTALLATION CONSIDERATIONSInstallation is normally preceded by a pre-installation survey of the facilities where the unit will beinstalled. The purpose of this survey is to ensure a successful installation. The following paragraphsdescribe issues that should be addressed during the pre-installation survey.

2.2.1 Site ConsiderationsThe installation site should be compatible with the location used for other electronic equipment. Thatis, the building should be free from excessive dust and moisture. The room should not exceed therecommended temperature range (see Section 1, OVERVIEW). The installation location should allowfor ample airflow. Also, allow extra room for service access to cables and wiring.

2.2.2 Power RequirementsThe AC power version of the SkyLane SL-2048 modem can accommodate power requirements foundworldwide. The DC power version of the SkyLane SL-2048 modem accepts either a plus or minus DCvoltage from any 32 to 72 VDC power source. Please verify that the power system used at theinstallation site provides a proper earth ground. In Addition, verify that the voltage setting matches thevoltage and power provided by the facility where it will be installed. Refer to Paragraph 1.4, TechnicalSpecifications for details.

20 SECTION 2. INSTALLATION


2.2.2.1 AC Powered VersionsAC power is applied to the SkyLane modem via the receptacle labelled P1 on the rear panel. Thispower receptacle is a standard IEC 320 3-prong male power receptacle that can be used to provide ACinput power to the unit.

NOTE:Only the U.S.-type power cord isshipped with the SL-2048. Becauseno international power cords areshipped with the SL-2048, you mustsupply an appropriate approved powercord for the country of installation.

s SL-2048 ist mit einer USA-Schnur nurgeliefert. Da es keine internationalenSchnüre mit demSL-2048 gibt, muß man einezugelassene Schnur passend für dasbesondere Land liefern.

The fuse assembly is attached to the bottom of the power receptacle and contains two fuses. Toremove the fuses, press down on the tab that extends out just below the power receptacle andbetween the two fuse holders. When replacing the fuses, make sure to use the exact type and ratingmarked next to the fuse holder. AC versions use a Time Delay 3.15 Amp 250 V fuse.

2.2.2.2 DC Powered VersionsDC power is applied to the SkyLane modem via a barrier strip labelled P1 on the rear panel. Thisbarrier strip has two screw terminals; one labelled (+) and the other labelled (-). The two inputterminals are floating (neither lead is connected to chassis ground), and therefore can accommodateeither a -48 VDC source, or a +48 VDC source. In either case, do not tie either the plus or minus leadfrom the source to chassis ground. DC versions use a Time Delay 6.3 Amp 250 V fuse.

2.2.3 Link Budget AnalysisThere are many satellites available at Ku or C-band with different transmission parameters (power,bandwidth, sensitivity, etc.), different tariffs for their use, different operational requirements and underdifferent regulatory environments. The link budget problem normally consists of determining theoptimum economic solution for the particular network requirements, given the satellite parameters, theprice for utilisation of power and bandwidth and the operational restrictions that may apply.

Link budgets for SkyLane SL-2048 should always guarantee a minimum Eb/N0 for worst caseconditions, as a function of the availability requirements of the network. This minimum Eb/N0 is the onerequired for BER of 10^-07. Table 2.1 illustrates the minimum Eb/N0 required for different bit rates andcode rates. Any necessary link margins shall be added on top of the table value. This includes rainmargin, pointing loss, etc. For example, if a 3-dB rain margin is added, the link will normally beoperating at better than 10E-10 BER under clear sky conditions. Table 2.1 also shows examples of theallocated bandwidth (or channel spacing) for each of the carrier types.

Note: Refer to Appendix B for a table of values for Eb/N0 based on (S+N)/N.



Table 2.1. Allocated Bandwidth for each Carrier Type

Channel Spacing (Rounded) Eb/N0 @ 10^-07 (Typical)Transmission MethodViterbi & Viterbi R/S Viterbi Viterbi + R/S Viterbi Viterbi + R/S

2048 kbps, QPSK, rate 1/2 2870 kHz 3025 kHz 6.5 4.4









128 kbps, BPSK, rate 1/2 360 kHz 390 kHz 6.5 4.4








Transmission MethodTurbo

Channel Spacing(Rounded)

Eb/N0 @ 10E-07(Typical)

2048 kbps, QPSK, rate 3/4 2085 kHz 4.1





Out-of-beam emission limits or downlink emission limits as defined by the regulatory environment in thecountry where the network is being installed are also an issue: there may be a limit on the minimumantenna size to be used.

2.3 INSTALLATIONMove the unit to the location where it will be installed. Ideally, the unit will be installed into anequipment rack or a shelf. Follow these precautions:

1. Do not block the air holes or the fan cut outs along the sides of the unit, these openings must bekept clear for the proper cooling of the equipment.

2. Do not place the units beside each other or on top of each other. The exhaust from one unit canbe drawn into the air intake of another.

3. Make sure the room is properly cooled. Normally cooling may not be sufficient for locations wherethe electrical equipment is installed. See the environmental specifications in Table 1.2, TechnicalSpecifications, for details.

4. Always make sure the unit’s top cover is installed and secured in place.

5. If it has not already been done, label each cable that will be attached to the unit. This will preventconfusion and ensure for the proper connections.



2.3.1 Modem Rear SupportPrior to installing the SL-2048 unit into a rack or shelf, the depth of the supporting structure must bedetermined. Three modem rear support kits are available to secure the SL-2048 unit firmly on to thesupporting structure:

1. Kit with part number 19A-230001-001 is for rack mount structures with a depth of 600 mm,

2. Kit with part number 19A-230011-001 is for structures with a depth of 800 mm and

3. Kit with part number 19A-230021-001 is for structures with a depth of 700 mm.

Each kit contains two supports, two angles and the associated mounting hardware for the properinstallation on the supporting structure. Figure 2.1 illustrates how to install the rear support kits on tothe SL-2048 unit.

Figure 2.1. SL-2048 Rear Support Kit Installation



Note: The left and right supports are attached to the SL-2048 unit with two #6-32 x 5/16 inch Phillipscountersunk screws. Each angle is attached to a support by one #8-32 x 1/2 inch screw, one# 8 lock washer, one #8 flat washer 3/8 inch outer diameter, one #8 flat washer 1/2 inch outerdiameter, and one #8-32 hexagonal nut.

2.3.2 Data ConnectionsThere is an RS-530 synchronous data port (J6), RS-232 asynchronous Monitor and Control data port(J3), and an RS-485 asynchronous Monitor and Control data port (J2) on the back of the chassis. TheRS-485 data port may be used to manage the BUC and the LNB/BDC. The front panel includes anRS-232 asynchronous M&C data port using a RJ-11 (6-pin) telephone jack. Refer to Figure 1.2 forconnector locations. Appendix A provides most of the connector pinouts for the various interfaces.

2.3.2.1 Data Port RS-530Receive and transmit data connections are accomplished through the 25-pin female D connectorlabelled TX/RX DATA, RS-530 on the rear panel. Connector pinouts are in Appendix A, Table A.3.See the description of the TINTCLK command for data clock options related to the TX data input(Paragraph 3.2.1).

Appendix A also provides cable pinouts that convert from an RS-530 interface to a RS-422/449interface. These cables and the appropriate pinouts are provided in Appendix A, Table A.1.

2.3.2.2 10BaseT EthernetWhen the data port is configured as a 10BaseT Ethernet port, a RJ-45 female connector is installed onthe rear panel, replacing the 25-pin RS-530 connector. Connector pinouts are in Appendix A,Table A.4. Appendix A, Figure A.1 is the RJ-45 connector pin arrangement looking into the connector.

2.3.2.3 Monitor and Control RS-232Rear panel remote monitor and control functions can be accomplished by the use of a hand-heldterminal with a RJ-11 to 9-pin D adapter, or with a VT-100 terminal emulator program running on anyPC. The terminal is connected to the 9-pin female D connector labelled M&C/RS-232 (J2) on the rearpanel, via a straight through cable. The connector pinouts for J2 are in Appendix A, Table A.5. TheRJ-11 to 9-pin D adapter is shown in Appendix A, Table A.8. The connector pinouts for a null modemcable assembly is shown in Appendix A, Table A.6.

The front panel RJ-11 connector is wired as shown in Appendix A, Table A.8. Appendix A, Figure A.2shows the pinout for the RJ-11 connector, when looking into the connector.

2.3.2.4 Monitor and Control RS-485The rear panel 9 pin D connector labelled M&C RS-485 (J3) is provided for RS-485 compatible monitorand control of the SkyLane modem and BUCs that are so equipped. The connector pinouts for J3 arein Appendix A, Table A.7.

2.3.3 BUC and LNB/BDC ConnectionsSkyLane SL-2048 modems are capable of being used in conjunction with most C-band or Ku-bandRFTs, with L-Band IF frequencies (950-1450 MHz). A typical installation is illustrated in Figure 2.2.Two separate coaxial cables are required, one for transmitting signal and one for receiving.

Because the coaxial cable requirements vary depending on the application, they are not supplied withthe equipment. On the transmit side, the connection between the SkyLane SL-2048 and the BUC isstraightforward. The output of the Modulator (Type N, female, 50 ohms) should be connected directlyto the Transmit IF connector of the BUC.

The cable loss must be considered when selecting the cable and adjusting the transmit level of thestation. See Transmit Levels (Paragraph 2.3.5) below for more information. The BUC is typicallyprovided with DC power and a 10 MHz reference on the same cable as the L-band transmit carrier.Both the DC power and the reference can be turned on and off at the SkyLane SL-2048 modem.



Figure 2.2. Typical SkyLane SL-2048 Interconnection

Antenna

SL2048

BUC

LNB

OUTDOOR

Rx 950 - 2050 MHz

Tx 950 - 1450 MHz

(ODU)

INDOOR

(IDU)L-band ModulatorL-band DemodulatorM&C InterfaceComplete ODU Interface

Secondary M&C Interface RS -485

Data PortRS -530

Antenna

SL2048

BUC

LNB

OUTDOOR

Rx 950 - 2050 MHz

Tx 950 - 1450 MHz

(ODU)

INDOOR

(IDU)L-band ModulatorL-band DemodulatorM&C InterfaceComplete ODU Interface

Secondary M&C Interface RS -485

Data PortRS -530

The input of the Demodulator (Type F,female, 75 ohms) should be connecteddirectly to the Receive IF connector ofthe (LNB/BDC). The cable loss must beconsidered when selecting the cable.The LNB is provided with DC powerand/or a 10 MHz reference on the samecable as the L-band receive carrier.Both the DC power and the referencecan be turned on and off at the SkyLaneSL-2048 modem.

2.3.3.1 IF Output to BUCTransmission of the L-band carrier tothe block up converter (BUC) isaccomplished by connections to thefemale N connector labelled IF OutputTo BUC, L-band 50 Ohms (J1) on therear panel. Three signals required bythe BUC are provided on this connector.

1. The L-band carrier: 950 to 1450 MHz, -5 to –25 dBm.

2. DC power for the BUC. +24 or +48 volts, options are available up to 4 Amps. The ON/OFF state ofthe BUC power is controlled by SW1 on the rear panel of the modem and is indicated by theassociated LED (illuminates green when DC is applied).

3. 10 MHz, 0 dBm synthesizer reference. The ON/OFF state of this reference is controlled by theTREF command.

2.3.3.2 IF Input from LNB/BDCReception of the L-band carrier from the Low Noise Block down converter (LNB/BDC) is accomplishedby connections to the female F connector labelled IF Input From LNB, L-band 75 Ohms (J5) on the rearpanel. Two signals required by the LNB are provided on this connector.

1. DC power for the LNB. +20 volts, 0.4 Amps. The ON/OFF state of the LNB power is controlled bySW2 on the rear panel and indicated by the associated LED (illuminates green when DC isapplied).

2. 10 MHz, 0 dBm reference. The ON/OFF state of this reference is controlled by the RREFcommand.

The cable also supplies 950-2050 MHz IF to the demodulator from the LNB/BDC.

2.3.4 Front Panel Controls and IndicatorsThe SL-2048 includes a RJ-11 connector for monitoring and controlling the modem from either ahand-held terminal or a PC with a terminal emulator program. In addition, a set of 7 Light-Emitting-Diode (LED) indicators provides an instantaneous overview of modem operation.

2.3.4.1 LEDsThe LEDs indicate critical system status information as illustrated in Figure 2.3 and described in Table2.2. LEDs that illuminate GREEN indicate that the function is in operation. LEDs that illuminate REDindicate a fault condition.



Table 2.2. Front Panel LED Indicators

LED DescriptionBUC Pwr: Indicates that SW1 on the rear panel is on and D.C. power is available to the BUC at J1.

LNB Pwr: Indicates that SW2 on the rear panel is on and D.C. power is available to the LNB at J5.

TX On: Indicates that the modulator is transmitting.

RX Lock: Indicates that the demodulator is locked to a received signal.

TX Fault: Indicates a fault on the modulator or that serial communications with the modulator have been lost.

RX Fault: Indicates a fault on the demodulator or that serial communications with the demodulator have been lost.

2.3.4.2 Front Panel Monitor and Control Using Hand-Held TerminalThe RJ-11 phone jack on the front panel is intended to be used with a hand-held terminal or othersimilar device that is compatible with ANSI 3.64 (VT-100) format. The 6-pin phone jack includes anRS-232 asynchronous interface, plus pins that supply +5 VDC to the hand-held terminal (for ANSI3.64/VT-100 terminals, the DC power pins are not used).

Such a device is the Model 8045EK R2-1 (Figure 2.4) hand-held terminal manufactured by TwoTechnologies, and can be purchased through SPL/ACT Wireless (Model No. 8045EKR2-1), the latter ofwhich includes a cable for connecting to the SL-2048 front panel RJ-11M&C.

This rugged hand-held terminal emulates a fully functional ANSI 3.64(VT-100) format, and is compatible with the SL-2048 modem. It includesa high-clarity Liquid Crystal Display (LCD) and a 45-key membranekeypad. The transreflective LCD display presents 4 rows of 20characters. Characters are dark on a light background.

The keypad layout is 9 rows x 5 columns, with the top row being functionkeys (F1 through F5). These function keys are currently not used inaccessing modem functions. The remaining 40 keys provide up to 70alphanumeric functions, a control (CTRL) key, an escape (ESC) key, abackspace (BACKSP) key, a SPACE key, an ENTER key, and a SHIFTkey.

It is powered from +5 VDC, 50 ma that is supplied by the SL-2048modem through either the RJ-11 M&C connector on the front panel, orJ2 (9-pin) on the rear panel. When attaching the hand-held terminal toJ2, a 9-pin to RJ-11 adapter must be used.

Figure 2.4. Hand-HeldTerminal

Figure 2.3. Exploded View of Front Panel LEDs and M&C RJ-11 Jack.

M&C/RS-232

Prime PwrRX FaultTX FaultRX LockTX OnLNB PwrBUC Pwr



10 100 200 300

Length of LMR-600 Cable (ft)

BU

C In

put L

evel

(dB

m)

-40

-35

-30

-25

-20

-15

-10

-5

950 MHz 1450 MHz

2.3.5 Transmit LevelsThe output power level of the modulator is adjustable from -5 to –25 dBm, but is only calibrated from-5 to -20 dBm. The TX gain past the modulator output should be set for the desired EIRP level of theEarth Station. The ideal situation is to have the gain of the BUC set to give a rated output power with-20 dBm input. Figure 2.5 illustrates the power reaching the BUC versus the length of cable betweenthe modulator and the BUC for two frequencies and with the modulator at maximum and minimumoutput power. Figure 2.5 assumes the use of LMR-600 cable from Times Microwave Systems (SeeAppendix A, Paragraph A.10 for partnumber).

The shaded area in Figure 2.5 indicatesthe useful range of the signal poweravailable from the modulator output, atthe BUC input (for any length of cable upto 300 feet). Figure 2.5 also illustratesthe following points:

1. LMR-600 cable is low-loss. If cablewith a more typical loss of 12 dB per100 feet is used, the maximum cablerun is approximately 100 feet.

2. Other cables can be substituted forthe LMR-600 Times MicrowaveSystems cable, such as theCommScope 3227 cable, which hasan attenuation of 6.05 dB @1800 MHz, which will increase thedistance from the modem to the BUC by up to 200 feet.

3. The power and gain of the BUC is assumed to be a 5 Watt (37 dBm at 1 dB compression) unit witha fixed gain of 50 dB. This chart indicates that the BUC will be in compression with a 300 ft cableand the modem output set to +5 dBm and the highest frequency.

4. Slightly longer cable lengths are possible with BUCs of higher gain, though the slope delta worsensfrom the low frequency of 950 MHz to the high frequency of 1450 MHz.

5. Through the use of special slope equalizers and amplifiers, the distance between the modem andthe BUC can be extended.

It is important to note that a DC voltage (12, 24 or 48 volts) and a 10 MHz reference signal may bepresent at the modulator output. The DC voltage may supply up to 4 Amps and will damage any DCcoupled device (such as an attenuator) connected to the modulator output. Also, a typical attenuatoron the modulator output would reduce the level of 10 MHz reference signal available to the BUC.

Special inline 10 and 20 dB attenuators are available from SPL/ACT Wireless that pass DC (up to6 Amperes) and 10 to 50 MHz reference in either direction and only attenuate the L-band signals by theamount of the attenuation.

There are also amplitude/slope equalisers available that compensate for losses and “tilt” caused by thecable and other devices between the modem and the BUC, such as power combiners. Some arerack-mounted units, which include self-contained power supplies, and others are in-line modules thatutilise the DC power from the modem (single modem, not multiple modems). Contact SPL/ACTWireless for more details on these devices.

Figure 2.5. Power Loss in LMR-600 Cableversus Cable Length and Frequency



2.3.6 Bringing the Modulator OnlineWhen bringing a transmit carrier on line, the following sequence must be followed:

1. Power on the modem for five minutes to allow the ovenized oscillator to stabilize.

2. Before connecting the L-band cable to the BUC, verify that:

• The frequency of the modulator and demodulator is set to the correct frequency. SeeParagraph 2.3.7 for details on the conversion factor for determining the output and inputfrequency from the L-band output and input frequency.

• The modulator is off (TM OFF),• BUC power is off (SW1 on rear panel), and• 10 MHz reference is off (TREF OFF)

3. Set modulator power to –25 dBm (TLEVEL –25).

4. Turn on DC power to BUC (SW1 on rear panel).

5. Turn on 10 MHz reference to the BUC (TREF ON).

6. Increase modulator output power to desired level (TLEVEL < desired level >).

2.3.7 Translation from L-Band to Transmit/Receive BandsUnderstanding and calculating the transmit and receive frequency is important to insure the terminal isworking at the assigned frequency. Normally, this translation is simply subtracting the assignedfrequency from the PLO in the BUC and LNB/BDC to determine the L-band frequency. For example,for a C band BUC, the translation frequency is normally 4900 MHz. Assuming that the assignedtransmit frequency is 6000 MHz:

Then: 6000 MHz – 4900 MHz = 1100 MHz. The modulator would then be set to1100 MHz for this example.

This is considered a low side mixer in the BUC, since the PLO in the BUC is below the outputfrequency. In this case, the output is non-inverted, meaning that the output spectrum is the same asthe input.

In some cases, such as low cost C band LNBs or Ku band BUCs, the spectrum may be inverted,whereby the LNB mixer (and filter) picks off the high side from the mixer, and the PLO is higher thanthe incoming frequency. Assuming a standard 3700 to 4200 MHz frequency bandwidth and thetranslation frequency is 5150 MHz:

Then: 5150 MHz - 3700 MHz = 1450 MHzand

5150 MHz - 4200 MHz = 950 MHz

Notice that the spectrum is inverted. The low C band frequency is at the high L-band frequency andthe high C band frequency is at the low L-band frequency. The actual spectrum will also be inverted.

It gets even more complicated if either the BUC or LNB/BDC utilises dual conversion, since one wouldhave to know the frequency of both PLOs, and whether it is a high side mix or a low side mix.However, usually the reason for the dual conversion technique is to insure that the output isnon-inverted, and it would simply be a calculation of the delta between the PLOs. One such BDCutilises 9800 MHz and 7125 MHz, respectively. Both use low side mixing, meaning that the signal inputis always lower than the PLO (on the input, the 3625 MHz frequency is lower than 9800 MHz, and

NOTE:Before attempting to bring the modulator on line, the operator should become familiar with theoperation of the modem while off line. Refer to SECTION 3. OPERATION, to obtain athorough understanding of modem operation using a terminal emulator (or hand-held terminalor PC with terminal emulation program).



between the stages, the 6175 MHz (9800 MHz - 3625 MHz) is lower than 7125 MHz. Solving theconversion using the two stage mixing,

Then: (9800 MHz - 3625 MHz) - 7125 MHz = 950 MHz

The result of subtracting the higher PLO frequency from the lower frequency PLO yields 2675 MHz(9800 MHz - 7125 MHz = 2675 MHz),

Then: 3625 MHz - 2675 MHz = 950 MHz

The result is the same. Using this BDC, setting the demodulator frequency to 950 MHz would accept areceive signal of 3625 MHz.

A translation frequency for standard Ku band BUCs (14.00 to 14.50 GHz) is 13.050 GHz. A translationfrequency for an inverted Ku band BUC (14.0-14.5 GHz) is 15.400 GHz. A translation frequency forstandard Ku band LNB/BDCs is as follows:

• 10.95-11.20 GHz = 10.00 GHz• 11.45-11.70 GHz = 10.50 GHz• 11.70-12.20 GHz = 10.75 GHz• 12.25-12.75 GHz = 11.30 GHz

It is up to the systems integrator to understand the translation frequency of the BUC and the LNB/BDCto correctly set the modulator and demodulator frequencies.

SECTION 3. OPERATION 29


SECTION 3. OPERATION

3.0 INTRODUCTIONThis section describes the SkyLane SL-2048 remote control, simplified user interface, set-up menuoperation, transmit control commands, receive control commands and monitor commands for bothtransmit and receive. A table of standard configuration settings is shown in Table 3.1.

Table 3.1. SL-2048 Standard (L-Band or 70 MHz) Configurations

PARAMETER MODULATORCOMMAND

DEMODULATORCOMMAND REMARKS

Frequency (L-Band) TCAR xxxxxxxxxx RCAR xxxxxxxxxx Set to RF output or inputfrequency in Hertz.RLBAND must be set toON.

Frequency (70 MHz) (Optional) TCAR xxxxxxxx RCAR xxxxxxxx Set to IF output or inputfrequency in HertzRLBAND must be set toOFF.

Data Rate TDATA yyyyyy RDATA yyyyyy Set to data rate in Hertz

Code Rate TRATE 1, 3 or 7 RRATE 1, 3 or 7 Set to code rate ½, ¾ or as required

Differential Encoder/Decoder TDIF ON RDIF ON

Scrambler/Descrambler TSCR ON RDESC ON

BPSK/QPSK TBPS OFF or ON RBPS OFF or ON Set as required. OFF isQPSK

Spectral Invert ON/OFF TSPI ON or OFF RSPI OFF Set modulator to ON if RFset-up inverts spectrum

Scrambler Algorithm TCCI ON RCCI ON

Transmit Power Level TL -5 TO -40 dBm Set as required

Modulator ON/OFF TMOD ON Required setting (ON)

Modulator CW ON/OFF TCW OFF Required setting (OFF)

Modulator Data ON/OFF TEXT ON Required setting (ON)

Modulator CTS ON/OFF TCTS ON Required setting (ON)

Modulator Clock INT/EXT TINT ON Not used when R/S orTurbo option is used

Clock Invert ON/OFF TCINV OFF RCINV OFF

Data Invert ON/OFF TDINV OFF RDINV OFF

Demodulator Sweep Range RSWE 24000 Set per LNB stability

Demodulator Acquisition Range RACQ FFT

Modulator Viterbi ON/OFF TVIT ON

Modulator Reference ON/OFF (1) TREF ON or OFF Set as required

Modulator IESS ON/OFF TIESS ON Required setting (ON)

Modulator Burst ON/OFF TBUR OFF Required setting (OFF)

Modulator Test ON/OFF TQTEST OFF Required setting (OFF)

(1) Not available for 70 MHz configurations.

Required settings are for normal operation. The complementary settings are test modes.

If the SL-2048 modem is equipped with the optional Reed Solomon outer codec, then Table 3.2provides the additional commands for modem configuration:

30 SECTION 3. OPERATION


Table 3.2. SL-2048 Additional Settings Equipped with Reed Solomon



Outer Reed Solomon CodeRate

TRSRATE 126, 225, 219,194, or OFF

RRSRATE 126, 225,219, 194, or OFF

Set as required

Clock Timing TXCLK OFF, TT, or RT Set as required

Clock Invert TCINV ON or OFF RCINV ON or OFF Set as required

Data Invert TDINV ON or OFF RDINV ON or OFF Set as required

Receive Buffer RBUFFER OFF, TXCLK,or EXT

Set as required

Receive Buffer Centre TBC Centre buffer wheninvoked

Receive Buffer Depth TBD xxxx Set to 0-2047

Receive Buffer Flag TBF Reset buffer flag wheninvoked

Modem Baseband Loopback TMBL ON or OFF TMBL ON or OFF Required setting is OFF

If the SL-2048 modem is equipped with the Turbo option, then Table 3.3 provides the additionalcommands for modem configuration.

Table 3.3. SL-2048 Additional Settings Equipped with Turbo



Select Viterbi or Turbo TCODE V or T RCODE V or T Set as required

Code Rate TRATE 1, 3, 7 for Viterbi;TRATE 3 for Turbo

RRATE 1, 3, 7 for Viterbi;RRATE 3 for Turbo

Set as required

Clock Timing TXCLK OFF, TT, or RT Set as required

Clock Invert TCINV ON or OFF RCINV ON or OFF Set as required

Data Invert TDINV ON or OFF RDINV ON or OFF Set as required

Receive Buffer RBUFFER OFF, TXCLK,or EXT

Set as required

Receive Buffer Centre TBC Centre buffer wheninvoked

Receive Buffer Depth TBD xxxx Set to 0-2047

Receive Buffer Flag TBF Reset buffer flag wheninvoked

Modem Baseband Loopback TMBL ON or OFF Required setting is OFF

3.1 REMOTE MONITOR AND CONTROL FUNCTIONSTwo asynchronous serial ports are available for the external monitor and control of the receiverfunctions. One input is a 9-pin female D connector on the rear panel and the other is a RJ-11 jack onthe front panel. Examples of ASCII terminals which can be used are as follows: 1) a stand-aloneterminal such as a VT100, 2) a hand-held terminal such as the Model 8045EK R2-1, or 3) a PC usingterminal emulation software. The terminal must be set to 9600 baud, No Parity, 8 Data bits, and 1 Stopbit (9600,8,N,1).

If the RS-232 is connected to a PC, such as a laptop or notebook, and the PC is operating in MSWindows, the PC can communicate with the SL-2048 using an MS Windows program calledHyperTerminal. (This is under Accessories – Communications – HyperTerminal.) UnderHyperTerminal, type a name, hit OK, then change CONNECT field to Direct to Com 1 (or whicheverCom port is being used). Hit OK, then enter: 9600 baud, no parity, 8 data bits, 1 stop bit and set flowcontrol to none.



The following hints may be helpful in establishing communication with the modem:1. The cable should be wired pin for pin (for pins 2, 3 and 5), 9-pin male to 9-pin female (no

crossover).

2. Insure that the ground (pin 5) is connected between the modem and the PC.

3. Pin 9 is used for powering the hand-held terminal as described above (+5 VDC @ 50 ma). This pinis normally not used, and shouldn’t cause any problems.

3.1.1 RS-232 Rear Panel Remote M&CTo use the rear panel connector, attach an ASCII terminal to the D connector labelled M&C RS-232 J2.The input data is applied to pin 3, and the output data is available at pin 2 of the SkyLane SL-2048modem. A standard one to one cable from the 9-pin COM port of a PC will provide the properconnection. Pin 9 has +5 VDC and pin 5 has the 5 VDC RTN that may be used to power the optionalhand-held terminal.

Either the RS-232 port from the rear panel or the front panel can be used to set the address of themodem using the MCADD command. This address must be unique to each SL-2048 modem thatshares the RS-485. Either of these two RS-232 ports must also be used to set the RS-485 to either asimplex (2-wire) or full duplex (4-wire) mode. Refer to Paragraphs 3.1.2 and 3.8.1 for furtherinformation and instructions for setting the ADDRESS and WIRE commands.

3.1.2 RS-485 Rear Panel Remote M&CA dual function RS-485 port is also present at the rear panel. The port can be set for 2- or 4-wireoperation using the WIRE command. For monitor and control over this RS-485 M&C port, eachcommand must be preceded by the unique M&C address for the unit using the MCADD command.The address must precede the command being issued, with the ending of the address being separatedby a SPACE. Refer to Paragraph 3.8.2 for an example of a command and response when using thisport.

The MCADD command must be accessed and changed using one of the RS-232 ports at either thefront or rear of the modem. See Paragraphs 3.1.1 and 3.8.1 for a detail regarding the MCADD andWIRE commands. Using the RS-485 port allows a number of SL-2048 Modems to be controlled from asingle RS-485 port on a PC. Each SL-2048 being controlled on the same bus must have a uniqueaddress set.

3.1.3 Simplified User InterfaceSetting the user configuration is easily accomplished by using the SETUP feature of the SkyLaneSL-2048 modem. Each user-controlled parameter in the modulator is listed one at a time, and the useris given the opportunity to change that parameter. When the modem is first powered up, the messageACT Wireless SL-2048 appears and then followed by HH>. HH> is the prompt from which allcommands are entered from, followed by the ENTER key.

To enter the SETUP menu for the modulator type TSET at the HH> prompt. To exit a SETUP menu,push Ctrl-C at the NEW: prompt. To return to the previous setting, or to reverse the order of the items,push Ctrl-P at the NEW: prompt.

3.1.3.1 Standard (L-Band or 70 MHz) SETUP MENU ExampleTo set up the L-band modulator, type TSET at the prompt, and then press the enter key to use theSETUP menu. The first user-controlled parameter in the menu is the carrier frequency. After a briefmessage, the following screen will appear:

Frequency in HzL-Band = 950000000 (Assuming the carrier frequency was set to 950000000)NEW:

At this time, the user can enter a new carrier frequency.



Type 1234567890, then press Enter, and the following screen will appear:

Frequency in HzL-Band = 950000000 (Assuming the carrier frequency was set to 950000000)NEW:L-Band = 1234567890

The carrier frequency has now been changed to this new value. The next user-controlled parameter willthen appear.

The 70 MHz modulator operates similarly, but the following screen will appear:

Frequency in HzIF = 52000000NEW:

At this time, the user can enter a new carrier frequency, then presses the ENTER key, and the newcarrier frequency will be displayed.

3.1.3.2 Standard (L-Band and/or 70 MHz) SETUP MENU OperationThe cursor will always appear after the NEW: prompt when using SETUP. The user can type in a newvalue and then press the enter key to change the value for this parameter. If the user enters an invalidnumerical value, the terminal will beep and the user will again be prompted for a new value. SomeASCII terminals may not support the BELL character, and therefore the beep would not be heard. Thefollowing is a summary of the SETUP MENU operation:

KEYSTROKE RESULTENTER No change to current item. Proceed to the next item.

<Valid Input>Enter Change current item to <Valid Input>. Proceed to the next item.

<Invalid Input>ENTER No change to current item. Return to the current item.

<Any Input>Ctrl-X No change to current item. Return to the current item.

Ctrl-N No change to current item. Proceed to the next item.

Ctrl-P No change to current item. Return to the previous item.

Ctrl-C No change to current item. Exit from the SETUP MENU.

Holding the control key while pushing the letter indicated enters the control key commands. TheENTER key is not used with the control key commands.

If the ENTER key is pushed each time the NEW: prompt appears, each user-controlled parameter willappear once, and the SETUP operation will stop after the last item. When using Ctrl-N or Ctrl-P theitems will appear in a circular fashion. For example, if you are at the first item and you enter Ctrl-P,SETUP will take you to the last item.

3.1.4 Display Configuration (Modulator Only)Type TCONF at the prompt, then press the ENTER key to view the current configuration of theSkyLane SL-2048 modulator or demodulator respectively. The current setting of each user-controlledparameter will be displayed. To accommodate the hand-held terminal, only four lines of the output aredisplayed on the screen at a time. A brief pause will occur after four lines have been displayed, andthen four more lines will be displayed. Pressing any key during the pause will make the next four linesappear immediately. The display returns to the HH> prompt when the last parameter has beendisplayed after a brief pause.

3.1.5 Display Status (Modulator Only)Type TSTAT at the prompt, and press the ENTER key to view the status of parameters for the SkyLaneSL-2048 modulator or demodulator respectively. The terminal will display four lines at a time. A briefpause will occur after four lines have been displayed, and then four more lines will be displayed.



Pressing any key during the pause will make the next four lines appear immediately. The displayreturns to the HH> prompt when the last parameter has been displayed after a brief pause.

3.2 MODULATOR (TRANSMIT) COMMANDSThe modulator commands are grouped into four types: control, test, configuration, and status. Controlcommands allow a parameter to be modified. Test modes allow the operator to activate certain built-intest functions that are helpful in testing and troubleshooting the modem, such as activating a BER testpattern, and etc. Configuration commands present the user-controlled parameters, such as frequency,data rate, code rate, and etc. Status commands present those parameters that are not user-controlled,such as BUC voltage and current, serial number of the modulator, software version of the modulator,lock status of the synthesiser, and etc. These are described in the following paragraphs.

3.2.1 Transmit Control CommandsThe following are all of the modulator control commands that allow an operator to change either asingle parameter without having to cycle through a series of items to reach the appropriate function, ora command that cycles through a group of functions, such as TSETUP described previously.

If for example, the user wishes to change the modulator from BPSK to QPSK modulation, thecommand TBPSK OFF, followed by ENTER, performs the function. All functions must be followed byENTER to implement the change. For monitor and control over the RS-485 M&C port, each commandmust be preceded by the unique M&C address set for the unit using the MCADD command. TheMCADD command must be accessed and changed using one of the RS-232 ports at either the front orrear panel of the demodulator.

Command DescriptionTBPSK [ON | OFF] If this command is entered with no argument, it indicates whether the BPSK Mode is on or

off. This command allows the modulator to be used in QPSK or BPSK systems with nochange to the hardware.

Example: TBPSK OFF

The BPSK Mode is not enabled. In this mode, the modulator will generate a signal thatuses QPSK modulation.

Example: TBPSK ON

The BPSK Mode is enabled.

TCAL [<setting>] The frequency of the reference oscillator can be changed with this command. Thisadjustment is performed only to counter the effects of frequency change due to the ageingoscillator. Do not attempt to change the CAL setting unless a frequency counter with anaccuracy exceeding .01 PPM is available. If this command is entered with no argument, itreturns the current setting of the frequency trimmer for the reference oscillator. To changethe setting of the frequency trimmer, enter the command followed by the desired setting.The range of valid values for <setting> is 0 to 4095. Changing this setting will cause anydemodulator that is locked to the modulator to receive a momentary burst of errors.

Example: TCAL 2047

In the example, the frequency trimmer is set to the middle point. This command should notbe used unless the proper test equipment is available. To set the frequency, the10 MHz reference at the modulator IF output must be ON (TREF ON).

TCARRIER[<frequency>]

If this command is entered with no argument, it returns the current L-band outputfrequency in Hz. To change the output frequency, enter the command followed by thedesired L-band output frequency in Hz. The range of valid values for <frequency> is950000000 to 1450000000.

Example: TCARRIER 950000000

The L-band input frequency is set to 950 MHz.

TCCITT [ON | OFF] If this command is entered with no argument, it indicates whether the scrambler is usingthe exact algorithm specified by CCITT V.35. When set to OFF, the scrambler uses aslightly modified algorithm, as called out in Intelsat specification IESS-308.

Example: TCCITT ON

The exact CCITT V.35 algorithm is used for scrambling.



Command DescriptionTCINV [ON | OFF] If this command is entered with no argument, it indicates whether the input clock inversion

is on or off. When TCINV is off, data is clocked into the modem with the rising edge of theclock being used (either SCTE or SCT).

Example: TCINV OFF

The input clock inversion feature is turned off. Data should be valid at the rising edge ofthe clock.

TCTS [ON | OFF] If this command is entered with no argument, it indicates whether the clear-to-send signalis on or off. This command controls the clear-to-send signal on the RS530 interface.When the modem Ethernet Bridge option is used, TCTS should be set to on.

TCW [ON | OFF] If this command is entered with no argument, it indicates whether the modulator istransmitting an unmodulated, continuous wave, carrier. When TCW is on, the modulatortransmits an unmodulated carrier. This command is used for testing ONLY, when it isdesired to measure the carrier frequency or CW amplitude. Reverts to OFF during powerup or reset.

TCW OFF also aborts the 4 minute timed CW test (invoked by TTIMCW ON).

TDATA [<rate>] If this command is entered with no argument, it returns the current data rate in bits persecond. To change the data rate, enter the command followed by the desired data rate inbits per second. The range of valid values for <rate> is 9600 to 576000 in integer steps.

Note: The high and low limits on data rate depend on the modulation type (TBPSK[ON | OFF] ) and the encoder rate TRATE [½| ¾|] as outlined below:

BPSK, ½ rate 9600 to 1100000

BPSK, ¾ rate 14400 to 1650000

QPSK, ½ rate 19200 to 2200000

QPSK, ¾ rate 28800 to 3300000

QPSK, 7/8 rate 33600 to 3850000

Example: TDATA 2048000

The data rate is set to 2048 kilobits per second. The user can also use the exponent formto set the data rate.

Example: TDATA 2.048e6 or TDATA 2048e3

Sets the data rate to 2048 kilobits per second.

TEXT [ON| OFF] If this command is entered with out an argument, it indicates whether the modulator isusing an external data source or the internal 2047 BERT pattern. When TEXT is set toON, the transmitted data is from the RS530 interface. This command is not availble withthe Turbo product code option.

Example: TEXT OFF

The transmitted data is a 2047 data pattern compatible with BER testers. This commandis not supported in the TPC version of the SL-2048.

TDIFF [ON | OFF] If this command is entered with no argument, it indicates whether the differential encoder ison or off.

Example: TDIFF ON

The differential encoder is turned on.

It is recommended that in Viterbi mode, TDIFF should be turned on. If it is turned off(RDIFF is also turned off), there is a 50% chance for the receiving data to be inverted.This command has no effect if the modem is in Turbo mode.

TDINV [ON | OFF] If this command is entered with no argument, it indicates whether the data inversion is onor off. This feature is provided for those systems where it becomes necessary to invert thedata.

Example: TDINV OFF

The output data inversion feature is turned off. The transmitted data will be the samepolarity as the data input to the modulator.

TIESS [ON | OFF] If this command is entered with no argument, it indicates whether the Viterbi encoder isusing the IESS or DVB algorithm. When IESS is set to ON, the encoder uses thealgorithm as called out in the Intelsat Specification IESS-308. When set to OFF, the DVBalgorithm is used. The DVB demodulator must have the Reed-Solomon disabled to befunctional.

Example: TIESS ON

The encoder uses the IESS algorithm. This command has no effect if the modem is inTurbo mode.



Command DescriptionTINTCLK [ON | OFF] If this command is entered with no argument, it indicates whether the data timing is

generated by the modem or by the DTE. When TINTCLK is on, the modem generates thedata timing and provides a data clock on the SCT (or ST) pins of the RS-530 interface.When TINTCLK is off, the modulator requires a clock on the SCTE (or TT) pins of theRS-530 interface at the programmed data rate ±100 ppm. The SCT clock pins are alwaysdriven by the SkyLane modem even when TINTCLK is off. This operation is illustrated inFigure 3.1. Thic command is not valid with the Turbo or the Reed-Solomon option. Therewill not be an SCT output with the Turbo or Reed-Solomon option.

TXCLK For an explanation of this command, see sections 3.4.1 and 3.5.1.

TLEVEL [<level>] If this command is entered with no argument, it indicates the current modulator outputpower level in dBm. To change the modulator output power level, enter the commandfollowed by the desired output level in dBm. The output power level may be changed from-5 to -49 dBm, but the only valid calibrated levels are from -5 to -20 dBm. The TMODcommand is used to actually turn the modulator on and off. TLEVEL merely sets what thelevel will be when the modulator is turned on.

TMOD [ON | OFF] If this command is entered with no argument, it indicates whether the modulator iscurrently transmitting an L-band carrier or not. When TMOD is on, the modulator willtransmit a signal power consistent with the current setting of the TLEVEL command.

TQTEST [ON| OFF] Modulator quadrature test mode. Used during factory testing only. Defaults to OFF duringpower up or reset.

TRATE [½| ¾|7/8] If this command is entered with no argument, it returns the current Viterbi encoder ratesetting. To change the encoder rate, enter the command followed by the desired encoderrate. Valid values for the encoder rate are ½, ¾ and 7/8.

Example: TRATE ½

This sets the code rate to ½.

TREF [ON | OFF] If this command is entered with no argument, it indicates whether the modulator iscurrently supplying a 10 MHz reference output. When TREF is ON, a 10 MHz ±0.1 ppm,0-dBm sine wave is sent to the RF output on J1.

TRFC Resets all modulator sticky bit faults. Refer to Paragraph 3.2.4 TFAULT for anexplanation.

TRPC Resets the parameter status change bit. Refer to Paragraph 3.2.4 TFAULT for anexplanation.

TSCRAM [ON | OFF] If this command is entered with no argument, it indicates whether the Scrambler is ON orOFF.

Example: TSCRAM ON

The Scrambler is turned ON.

TSETUP Refer to Paragraph 3.1.3 for explanation.

TSPINV [ON | OFF] If this command is entered with no argument, it indicates whether the modulator carrier isgenerated with an inverted spectrum. When TSPINV is on, the transmitted spectrum willbe inverted in frequency. This feature is provided for those systems that invert the transmitspectrum but require the received signal to be uninverted. In the BPSK mode, spectralinvert must be set to the OFF state to be compatible with the SL512 demodulator.

TTIMCW [ON | OFF] If this command is entered with no argument, it indicates the time left in seconds before themodulator carrier is returned to normal operation. When set to ON, it sets the modulatorinto a timed, four-minute CW carrier mode of operation. If the TTIMCW OFF or TCW OFFcommands are not issued, then the modulator will return to normal operation automaticallyafter four minutes. The command is recursive. If issued repeatedly, the modulator CWoperation will be extended another four minutes each time it is invoked. Reverts to OFFduring power up or reset.

TVIT [ON | OFF] If this command is entered with no argument, it indicates whether the modulator iscurrently Viterbi encoding the transmit data.

TWARM [0] If this command is entered with out an argument, it indicates how many seconds remainbefore the modulator output will turn on. If TWARM is set to 0 (zero), then the modulatoroutput will turn on as soon as the command is invoked.

Example: TWARM 0

The modulator output will turn on in zero seconds.



3.2.2 Modulator Operation for PowerTrack OptionThe SL-2048 has the added feature of providing output power control of a BUC manufactured bySierraCom or Advantech. A microprocessor controlled M&C function within the BUC interfaces via anRS-485 link to the SL-2048 modem. When a cable is connected between the BUC and the SL-2048,the modem can be used to turn the BUC on and off, provide status information, including temperatureand power output, and maintain the BUC power output level.

This option is only available with modulators equipped with the L-band output frequency.

With the M&C cable disconnected, the SL-2048 and the BUC operate independently, as is normal forBUCs that have no interface capability.

The BUC includes an output power monitor, with the output power being carefully calibrated overtemperature and frequency. The SL-2048 and with the PowerTrack activated, utilises the powermonitor information to accurately control the actual power level transmitted to the satellite.

3.2.2.1 Power Control Feedback LoopIdeally, the amount of power transmitted to the satellite will always remain constant. However,amplifier gain and cable attenuation varies with the temperature. The PowerTrack system reads theoutput power reported by the BUC, and adjusts the SL-2048 output power when necessary.

For example, if the amount of attenuation in the cable between the modulator and BUC increases, theoutput power reported by the BUC will decrease. The PowerTrack system detects the drop in powerlevel, and increases the SL-2048 power output to maintain the desired output power.

3.2.2.2 Control, Status and RS-485 Cabling for SierraCom BUCs and theAdvantech SSPBSection 3.4 of this manual lists all of the commands that are used to communicate with the SierraComBUC and the Advantech SSPB. The RS-485 cable that connects the SL-2048 to the SierraCom BUCand the Advantech SSPB M&C port is described in Section A.9 of this manual.

3.2.2.3 Enabling PowerTrackThe SL-2048 includes an RS-485 port on the rear panel labelled J3. This port must be set for 2-wireoperation to be compatible with the SierraCom BUC or Advantech SSPB equipped with PowerTrack.The command to enable 2-wire operation is:

Wire 2

The PowerTrack system should be turned off during the initial set-up. The command to disable thetracking function is:

SBTR OFF

The SierraCom BUC or the Advantech SSPB may be shipped with the transmitter defaulted to ON. Ifnot, issue the command to turn on the transmitter. The command to turn on the BUC transmitter is:

SBTX ON

The SierraCom BUC and Advantech SSPB report the output power in dBm. The command to monitorthe output power level of the BUC is:

SBPWR

The power level should be adjusted manually to obtain the desired output power. Refer to Section 3,Paragraph 3.2.1 for information on setting the output power of the SL-2048 modulator. The commandto set the SL-2048 output power level to -20 (-25) dBm is:

TLEVEL –20 (for SierraCom BUC), TLEVEL –25 (for Advantech SSPB)



Now set the desired SierraCom BUC or the Advantech SSPB output power in dBm. The command toset the target output power level of the BUC to +30 dBm is:

POWER 30

Monitor the BUC output power with the command:

SBPWR

This time, the PowerTrack feature can be enabled. The command to turn on PowerTrack is SBTR ON.

3.2.2.4 Monitoring PowerTrackThe SL-2048 modem will adjust the output power level of the modulator to keep the SierraCom BUC orthe Advantech SSPB output power level constant. The BUC power level reported by the commandSBPWR will not vary more than +0.2 dB.

3.2.3 Modulator Test ModesThe modulator has four test modes of operation, three of which default to OFF (if invoked) duringpower up or reset. The four commands are as follows:

TCW [ON | OFF] for unlimited CW operation. Defaults to OFF during power up or reset.

TTIMCW [ON | OFF] for four minute CW Operation. Defaults to OFF during power up or reset.

TQTEST [ON | OFF] for modulator quadrature mode. Defaults to OFF during power up or reset.

TEXT [ON | OFF] for internal BERT/ external DATA selection.

The modulator provides a return prompt to the user, indicating whether it is in a test or normaloperating mode whenever queried or commanded. The modulator prompt for normal operation isLMOD-97>. If the modulator were set for any of its test modes, then the prompt would be LMOD-TEST>. Another reporting prompt, LMOD-COLD>, occurs during a ninety-second warm-up period forthe modulator before the modulator output is enabled. After ninety seconds, the prompt reverts toLMOD-97> or perhaps LMOD-TEST> if the internal BERT option was ON.



Figure 3.1. SkyLane SL-2048 Transmit Clocking Options

3.2.4 Transmit Monitor CommandsThese are all of the modulator monitor commands that allow an operator to change either a singleparameter without having to cycle through a series of items to reach the appropriate function, or acommand that cycles through a group of functions, such as TCONF or TSTAT as described previously.If for example, it is desired to monitor the voltage being supplied to the BUC, the command TBUCfollowed by ENTER, reports the voltage being supplied to the BUC. All of the following functions mustbe followed by ENTER to view the contents.

Command DescriptionTBUC This command accepts no parameters. When entered it reports the voltage being

supplied to the BUC.

TBUCI This command accepts no parameters. When entered it reports the current beingsupplied to the BUC.

TCONF Refer to Paragraph 3.1.4 for an explanation.

TEEPROM Displays the part number and version number of non-volatile memory.

TRFC Resets all modulator “stick” bit faults. It also resets the parameter status change bit.

TRPC Resets the parameter status change bit. This bit is set each time a command parameteris executed. The parameter status change bit can also be reset by TRFC.

THELP Displays an alphabetical list of all commands in a format that fits the hand-held terminalscreen. Four lines are displayed, and the display will freeze for approximately fourseconds before displaying the next four lines. If the user presses a key, the display willadvance to the next four lines.

D

Q

Q

+-

+-

Clock Invert

TCINV

1

1

Clock Internal

TINT

0

1

Data Invert

TDINV

0

+

-

SCT ClockPLL

Hold

SD-A (2)SD-B (14)

TT-A (24)TT-B (11)

ST-A (15)ST-B (12)

Selected TX Data

Selected TX Clock

0

+

-

CTS-A (5)CTS-B (13) Modulator Fault Summary, Fault = 0

+-

RTS-A (4)RTS-B (19) Not used in the SCPC mode

RS-530 DB-25Female (DCE)

D

Q

Q



Command DescriptionDisplays the fault status of the modulator. The synthesiser fault will cause the modulatorto turn off. Some of the faults will continue to show a fault, even though the condition wascleared. The command TRFC will reset these “stick” bits. There are two commands thatwill reset the parameter change flag, TRFC and TRPC. The TFAULT will report themodulator faults as indicated below. The check marks in the Stick column are thosefaults that will continue to show a fault.

TFAULT

STICK

√

√√√

√

REPORT

Temp FLT

Warm-up FLT

Synthesiser FLT

Power Detector FLT

Parameter Change FLT

FPGA Load FLT

+12 VDC Supply FLT

DESCRIPTION/RANGE

Board temperature is <5oC or >70oC

Reported during 90 second warm-up period

Modulator synthesiser faulted

Detector is <40 or >254

Parameter change since last TRPC command.

Loading of an FPGA has failed

+12 VDC Power supply is <11 VDC or >14 VDC

TFIVE Displays the voltage of the modulator’s +5 volt power supply. This reading is accurate toapproximately ±10%.

TPN Displays the part number of the modulator assembly.

TSERIAL Displays the serial number of the modulator circuit board assembly.

TSTAT Refer to Paragraph 3.1.5 for explanation.

TSYNTH Displays the lock status of the modulator synthesiser.

TTEST Displays the state of the four test modes that the modulator may be in. It also reports thestate of the transmit clock as well as indicating that the FPGAs have been programmedproperly. Invoking the command, TTEST yields the following display for normal operation:

TXTEST DISPLAY

CW Mode = OFF

Timed CW Mode = OFF

Quad Test = OFF

Data = ON

INT CLK = ON

U100(1) = ON

U200(1) = ON

TX TEST DISPLAY

LMOD-97>

The modulator prompt for normal operation is LMOD-97>. If the modulator were set forany of its test modes, then the prompt would be LMOD-TEST>. Another reportingprompt, LMOD-COLD>, occurs during the ninety second warm-up period for themodulator before the modulator output is enabled. After ninety seconds, the prompt willrevert back to LMOD-97>, or perhaps LMOD-TEST> if the internal BERT option was ON.

TTWELVE Displays the voltage of the modulator’s +12 volt power supply. This reading is accurate toapproximately ±10%.

TVER Displays the part number and version number of the internal software.

T? Displays the help information in a full screen format.

3.3 DEMODULATOR (RECEIVE) COMMANDSThe demodulator commands are grouped into three types: control, configuration, and status. Controlcommands allow a parameter to be modified. Configuration commands present the user-controlledparameters, such as frequency, data rate, code rate, and etc. Status commands present thoseparameters that are not user-controlled, such as AGC voltage, serial number of the demodulator,software version of the demodulator, lock status of the synthesiser, and etc. These are described inthe following paragraphs.



3.3.1 Receive Control CommandsThese are all of the demodulator control commands. If for example, it is desired to change thedemodulator data rate, the command RDATA, followed by the value, then followed by ENTER,performs the function. All of the following functions must be followed by ENTER to implement thechange.

Command DescriptionRACQ [FFT|SWEEP] Refer to Paragraph 3.3.6 Carrier Acquisition for additional information regarding this

command. Selects the method used for acquisition. If this command is entered without anargument, it returns the current demodulator acquisition type. To change the acquisitiontype, enter the command followed by then desired type.

Example: RACQ FFT.

The demodulator will use the FFT mode when acquiring a carrier.

RBPSK [ON | OFF] If this command is entered with no argument, it indicates whether the BPSK Mode is on oroff. This command allows the demodulator to be used in QPSK or BPSK systems with nochange to the hardware.

Example: RBPSK OFF

The BPSK Mode is not enabled. In this mode, the demodulator will only lock to a signal thatuses QPSK modulation.

RCCITT [ON | OFF] If this command is entered with no argument, it indicates whether the descrambler is usingthe exact algorithm specified by the CCITT V.35 or the IESS 308 descrambler. When set toON, the descrambler uses the CCITT V.35 algorithm. When set to OFF, the descrambleruses a slightly modified algorithm, as called out in Intelsat specificationIESS-308.

Example: RCCITT ON

The exact CCITT V.35 algorithm is used for descrambling.

The user should set the demodulator parameter [RCCITT] to the same value as for[TCCITT].

RCINV [ON | OFF] If this command is entered with no argument, it indicates whether the output clock inversionis on or off. This feature is provided for those systems that expect the rising edge of the clockto occur in the middle of the data bit.

Example: RCINV OFF

The output clock inversion feature is turned off. The rising edge of the clock will occur at thetransitions.

RDATA [<rate>] If this command is entered with no argument, it returns the current data rate in bits persecond. To change the data rate, enter the command followed by the desired data rate inbits per second. The range of valid values for <rate> is 9600 to 3850000 in integer steps.

Note: The high and low limits on data rate depend on the modulation type (TBPSK [ON |OFF] )and the encoder rate TRATE [½| ¾|7/8] as outlined below:

BPSK, ½ rate 9600 to 1100000

BPSK, ¾ rate 14400 to 1650000

QPSK, ½ rate 19200 to 2200000

QPSK, ¾ rate 28800 to 3300000

QPSK, 7/8 rate 28800 to 3850000

Example: RDATA 64000

The data rate is set to 64000 bits per second.RDESC [ON | OFF] If this command is entered with no argument, it indicates whether the descrambler is on or

off.

Example: RDESC ON The descrambler is turned on.

The user should set the demodulator parameter to the same value as for [TDESC].

RDIFF [ON | OFF] If this command is entered with no argument, it indicates whether the differential decoder ison or off.

Example: RDIFF ON The differential decoder is turned on.

The user should set this parameter to ON when using the Viterbi decoder. This feature hasno effect while in Turbo. Also, the user should set the demodulator parameter to the samevalue as for [TDIFF].



Command DescriptionRDINV [ON | OFF] If this command is entered with no argument, it indicates whether the output data inversion is

on or off. This feature is provided for those systems where it becomes necessary to invertthe data.

Example: RDINV OFF

The output data inversion feature is turned off. The output data will be the same polarity asthe data input to the modulator.

RLBAND [ ON | OFF ] If this command is entered with no argument, it returns to the current setting of the inputignal for the demodulator. ‘OFF’ represents the 70 MHz input signal and ‘ON’ is for the L-and input signal. To change this setting, enter the command followed by the desired value.

Example: RLBAND OFF

The demodulator assumes a 70 MHz input signal and turns off the L-band tuner.

RADJC [ ON | OFF ] If this command is entered with no argument, it returns to the current center frequencyajustment mode. ‘ON’ means that the center frequency will be adjusted automatically and‘OFF’ manually. To change this setting, enter the command followed by the desired value.

Example: RADJC ON

The center frequency will be adjusted automatically.

RCENTER [<freq>] If this command is entered with no argument, it returns to the current 70 MHz or L-bandcenter frequency in Hz for the demodulator depending on the RLBAND value and if theRADJC is set to manual mode. To change the center frequency, enter the commandfollowed by the desired 70 MHz or L-band frequency in Hz. The range of valid values for<frequency> is 950000000 to 2050000000, in 100000 Hz steps (L-band input signal) and52000000 to 88000000, in 1 Hz steps (70MHz input signal). Important: Always set the centerfrequency before any carrier.

Example: RCEN 950000000

The L-band input frequency for the down converter used by demodulator is set to 950 MHz.

RCARRIER [<freq>] If this command is entered with no argument, it returns to the current 70 MHz or L-band inputfrequency in Hz for the demodulator depending on the RLBAND value. To change the inputfrequency, enter the command followed by the desired 70 MHz or L-band input frequency inHz. The range of valid values for <frequency> is 950000000 to 2050000000, in 100 Hz steps(L-band input signal) and 52000000 to 88000000, in 1 Hz steps (70MHz input signal).

Example: RCAR 950000000

The L-band input frequency for the demodulator is set to 950 MHz.

ROFFSET [<± frequency>] If this command is entered with no argument, it returns the current setting of the frequencyoffset in Hz. To change the offset frequency, enter the command followed by the desiredamount of frequency offset in Hz. The range of valid values for <± frequency> is 0 ± 32000,in 1 Hz increments.

Example: ROFFSET –8000

The frequency offset is set to –8000.

RRATE [ ½ | ¾ | ] If this command is entered with no argument, it returns the current decoder rate setting.

Example: RRATE ½

The demodulator decoder is set to ½ rate.

RREF [ON | OFF] If this command is entered with no argument, it returns the current setting of the LNBreference. When REF is ON, a 10 MHz, 0-dBm signal appears at the LNB input. Thisshould always be turned off, unless using an externally referenced LNB.

Example: RREF OFF

The 10 MHz reference at the L-band IF input is off.

RSPINV [ON | OFF] If this command is entered with no argument, it indicates whether the spectral inversion is onor off. This feature is provided for those systems that invert the spectrum in the frequencyconversion scheme. For a low side LO system, such as a typical Ku-Band LNB, SPINVshould be set to OFF.

Example: RSPINV OFF

The spectral inversion feature is turned off.



Command DescriptionRSWEEP [<width>] Refer to Paragraph 3.3.7 CCaarrrriieerr FFrreeqquueennccyy CCoonnffiigguurraattiioonn for additional information

regarding this command. If this command is entered with no argument, it displays thecurrent setting of the acquisition sweep range. This feature is provided to accommodatesystems with different ranges of frequency uncertainty. Changing this value will impact thelock time, but does not affect the performance of the demodulator. The range of valid valuesfor <width> is 1000 to 512000 in steps of 1 Hz.

Example: RSWEEP 8000

The demodulator will now sweep ±8 kHz during the carrier acquisition.

RCOMP [<range>] f this command is entered with no argument, it returns to the current composite signal powerevel in dBm for the demodulator (when using L-band input signal). To change this setting,enter the command followed by the desired value (range from –15 to –26 dBm). For bestresults, this should always be –20 dBm.

Example: RCOMP -20

The AGC will provide a –20 dBm signal level at the composite side.

3.3.2 Demodulators Equipped with 70 MHz IF InputsDemodulators equipped with 70 MHz IF inputs (refer to Table 1.1 to determine configuration) utilisesthe same command for setting the receive frequency as is used in L-band modems. The RCARRIERcommand will be used to configure the carrier frequency. Demodulators can also be equipped with theL-band tuner, giving the operator the ability to chose between either a 70 MHz input, or an L-bandinput. When using the 70 MHz input, the L-band tuner should be turned off with the followingcommand:

RLBAND OFF

3.3.3 Commands for Dual DemodulatorsModems (including receive-only versions) equipped with dual (2) demodulators are independentlytuned, provided that the two receive frequencies are spaced by no more than 5 MHz. The commandslisted below should be used in addition to the commands in Section 3.3.1 for the first demodulator.For these commands, the symbol [#2] indicates the syntax to command demodulator number two.

EXAMPLE:To set the data rate of demodulator number 1 to 32000 bps, use the command:

RD 32000

To set the data rate of demodulator number 2 to 32000 bps, use the command:

RD #2 32000

As with all commands, the ENTER button performs the function. The commands unique to the seconddemodulator are noted below.

Command DescriptionRCAR [#2] [<freq>]

RCAR [<freqA> <freqB>]

If this command is entered with no argument, it returns to the current 70 MHz or L-bandinput frequency in Hz for the demodulator depending on the RLBAND value. To changethe input frequency, enter the command followed by the desired 70 MHz or L-band inputfrequency in Hz. The range of valid values for <frequency> is 950000000 to2050000000, in 100 Hz steps (L-band input signal) and 52000000 to 88000000, in 1 Hzsteps (70MHz input signal).

Example1: RCAR #2 950000000

The L-band input frequency for demodulator 2 is set to 950 MHz.

Example2: RCAR 950000000 954000000

The L-band input frequencies for demodulators 1 & 2 are 950 and 954 MHz.



Command DescriptionRACQ [#2] [FFT|SWEEP] Refer to Paragraph 3.3.6 CCaarrrriieerr AAccqquuiissiittiioonn for additional information regarding this

command. Selects the method used for acquisition. If this command is entered withoutan argument, it returns the current demodulator acquisition type. To change theacquisition type, enter the command followed by then desired type.

Example: RACQ #2 FFT

The demodulator will use the FFT mode when acquiring a carrier.

RBPSK [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the BPSK Mode is onor off. This command allows the demodulator to be used in QPSK or BPSK systems withno change to the hardware.

Example: RBPSK #2 OFF

The BPSK Mode is not enabled. In this mode, the demodulator will only lock to a signalthat uses QPSK modulation.

RCCITT [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the descrambler isusing the exact algorithm as specified by CCITT V.35 or the IESS 308 descrambler.When set to ON, the descrambler uses the CCITT V.35 algorithm. When set to OFF, thedescrambler uses a slightly modified algorithm, as called out in the Intelsat specificationIESS-308.

Example: RCCITT #2 ON

The exact CCITT V.35 algorithm is used for descrambling.

The user should set the demodulator parameter [RCCITT] to the same value as for[TCCITT].

RCINV [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the output clockinversion is on or off. This feature is provided for those systems that expect the risingedge of the clock to occur in the middle of the data bit.

Example: RCINV #2 OFF

The output clock inversion feature is turned off. The rising edge of the clock will occur attransitions.

RDATA [#2] [<rate>] If this command is entered with no argument, it returns the current data rate in bits persecond. To change the data rate, enter the command followed by the desired data rate inbits per second. The range of valid values for <rate> is 9600 to 3850000 in integer steps.

Note: The high and low limits on data rate depend on the modulation type (TBPSK [ON| OFF] )and the encoder rate TRATE [½| ¾|7/8] as outlined below:BPSK, ½ rate 9600 to 1100000BPSK, ¾ rate 14400 to 1650000QPSK, ½ rate 19200 to 2200000QPSK, ¾ rate 28800 to 3300000QPSK, 7/8 rate 28800 to 3850000

Example: RDATA #2 64000

The data rate is set to 64000 bits per second.

RDESC [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the descrambler is onor off.

Example: RDESC #2 ON

The descrambler is turned on. The user should set the demodulator parameter [RDESC]to the same value as for [TDESC].

RDIFF [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the differential decoderis on or off.

Example: RDIFF #2 ON

The differential decoder is turned on.

The user should set this parameter to ON when using the Viterbi decoder. Thisparameter has no effect when using Turbo. Also, the user should set the demodulatorparameter [RDIFF] to the same value as for [TDIFF].

RDINV [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the output datainversion is on or off. This feature is provided for those systems where it becomesnecessary to invert the data.

Example: RDINV #2 OFF

The output data inversion feature is turned off. The output data will be the same polarityas the data input to the modulator.



Command DescriptionROFFSET [#2][<± frequency>]

If this command is entered with no argument, it returns the current setting of thefrequency offset in Hz. To change the offset frequency, enter the command followed bythe desired amount of frequency offset in Hz. The range of valid values for the<± frequency> is 0 ± 32000, in 1 Hz increments.

Example: ROFFSET #2 –8000

The frequency offset is set to –8000.

RRATE [#2][½ | ¾ | 7/8]

If this command is entered with no argument, it returns the current decoder rate setting.

Example: RRATE #2 ½

The demodulator decoder is set to ½ rate.

RSPINV [#2][ON | OFF]

If this command is entered with no argument, it indicates whether the spectral inversion ison or off. This feature is provided for those systems that invert the spectrum in thefrequency conversion scheme. For a low side LO system, such as a typical Ku-BandLNB, RSPINV should be set to OFF.

Example: RSPINV #2 OFF

The spectral inversion feature is turned off.

RSWEEP [#2] [<width>] Refer to Paragraph 3.3.7 Carrier Frequency Configuration for additional informationregarding this command. If this command is entered with no argument, it displays thecurrent setting of the acquisition sweep range. This feature is provided to accommodatesystems with different ranges of frequency uncertainty. Changing this value will impactthe lock time, but does not affect the performance of the demodulator. The range of validvalues for <width> is 1000 to 512000 in steps of 1 Hz.

Example: RSWEEP #2 8000

The demodulator will now sweep ±8 kHz during carrier acquisition.

3.3.4 Receive Monitor CommandsThese are all of the demodulator monitor commands that allow an operator to observe what ishappening with the demodulator. If for example, you wish to monitor the AGC voltage, the commandRAGC followed by ENTER, reports the AGC reading. All of the following functions must be followed byENTER to view the contents.

Command DescriptionRAGC Displays information relative to the level of the received signal. The display will present

the actual power level signal in dBm.

RBER Displays an estimate of the current bit error rate when the demodulator is locked.Note: This command is still under development.

RRBER Displays the number of raw errors detected by the decoder during the previous second.This command is useful only when the decoder is locked. The information is updatedonce each second.Note: This command is still under development.

RCD Displays the current carrier detect status. When the receiver is locked, the display willshow "Carrier Detect = ON".

RCONF Displays the configuration parameters of the demodulator.

RDEC Displays the current decoder lock status. When the receiver is locked, the display willshow "Decoder Lock = ON".

REBNO Displays the current Eb/No estimation when the demodulator is locked.

RHELP Displays an alphabetical list of all commands in a format that fits the hand-held terminalscreen. Four lines are displayed, and the display will freeze for approximately fourseconds before displaying the next four lines. If the user presses a key, the display willadvance to the next four lines.

R? Displays an alphabetical list of all commands in a format that fits into a standard terminalscreen. Some lines are displayed, however the display will freeze until the user pressesa key to view the next lines.

RPN Display the demodulator circuit board assembly part number.

RSERIAL Display the demodulator circuit board assembly serial number.

RROFFSET Displays the amount of frequency offset from the programmed frequency, in Hz[+ delta frequency].

RSYNTH Displays the status of the demodulator synthesiser.



Command DescriptionRSWVER Displays the version number of the internal software.

RSWDATE Displays the complete date of the internal software.

RSWNAME Displays the name of the FPGA internal software.

RSWSUM Displays the checksum of the internal software stored in the flash.

RSWALL Displays all of the software information above.

3.3.5 Monitor Commands for Dual DemodulatorsThe monitor commands that allow an operator to observe what happens to the second demodulator, isindependent from those for the first demodulator. The monitor commands listed below should be usedin addition to the monitor commands listed in Section 3.3.4 for the first demodulator. The symbol [#2]indicates the syntax to command demodulator number two. All of the following functions must befollowed by ENTER to implement the command.

Command DescriptionRAGC [#2] Displays information relative to the level of the received signal. The display will present the

actual power level signal in dBm.

RBER [#2] Displays an estimate of the current bit error rate when the demodulator is locked.

Note: This command is still under development

RRBER [#2] Displays the number of raw errors detected by the decoder during the previous second. Thiscommand is useful only when the decoder is locked. The information is updated once eachsecond.Note: This command is still under development

RCD [#2] Displays the current carrier detect status. When the receiver is locked, the display will show"Carrier Detect = ON".

RCONF [#2] Displays the configuration parameters of the demodulator.

RDEC [#2] Displays the current decoder lock status. When the receiver is locked, the display will show"Decoder Lock = ON".

REBNO [#2] Displays the current Eb/No estimation when the demodulator is locked.

RROFFSET [#2] Displays the amount of frequency offset from the programmed frequency, in Hz[+ delta frequency].

3.3.6 Carrier AcquisitionThe demodulator may be configured to use one of two methods to acquire the desired carrier. Themethod is selected by the RACQ command.

FFT mode will achieve demodulator lock very quickly, and is most often used. (For symbol rates >1 Msymbols per second, using the SWEEP mode may be a better choice.) The configured sweep widthmust be set narrow to prevent the adjacent carriers from being included into the sweep window in orderfor the FFT acquisition mode to function. Acquisition times are a function of the data rate, sweep width,and the Eb/No. Higher data rates, smaller sweep widths, and higher Eb/No values all reduce theacquisition time.

SWEEP mode will lock to a signal even in very low signal to noise ratio conditions. The configuredsweep width will impact the lock time. If adjacent carriers are using the same data rate, the sweepmust not be set too wide so as to pass through these carriers.

3.3.7 Carrier Frequency Configuration

3.3.7.1 ROFFSET and RCARRIER Input Frequency ConfigurationThe value stored by the command, ROFFSET, is algebraically added to (or subtracted from) theRCARRIER setting to determine the actual centre frequency for the demodulator. ROFFSET is usuallyreserved for centring the carrier by observing the contents of RROFFSET. RROFFSET (a monitor



command) displays the frequency offset of the received signal from the actual centre frequency for thedemodulator.

EXAMPLE1:Demodulator 1 desired input frequency: 70.000000 MHzRCARRIER 70ROFFSET 0RROFFSET +10000Actual centre frequency of the acquired carrier is 70 + 10000 = 70.010000 MHz

If you change ROFFSET to reflect the value displayed by RROFFSET, then the actual centrefrequency of the incoming carrier is still 70 + 10000 = 70.010 MHz, but RROFFSET should display nearzero.

From EXAMPLE1:Demodulator 1 desired input frequency: 70.000000 MHzRCARRIER 70ROFFSET 10000RROFFSET 0Actual centre frequency of the acquired carrier is 70 + 10000 = 70.010000 MHz.

3.3.7.2 Advanced Carrier Frequency Configuration

The demodulator includes a special circuit to down convert the L band input signal to 70 MHz. Thisdown converter has a frequency step size of 0.1 MHz, as noted in the description of the RCENTERcommand. A second circuit is used to down convert the 70 MHz signal. The centre frequency of thisdown converter is set also by the RCENTER command. The final frequency selection is configured withthe RCARRIER command.

In normal operation RADJC will be set to ON to automatically adjust the down convert frequencies. Butfor example if you are using a dual demodulator, every time a change is made on carrier, data rate,code rate, modulation type the down convert frequency will be updated to be at the centre of bothcarrier.

In manual mode the user will have to set the down convert frequency before any carrier. The user haveto know that the maximum bandwidth between both carrier must be 5MHz. The major advantage of thismode is to be able to modify a carrier frequency without interrupted the second one. Following are fewexamples of programming the input frequency:

EXAMPLE 1 (L band input, dual demodulator with RCENTER adjusted auto)Demodulator 1 Desired Input Frequency: 1200.025 MHzDemodulator 2 Desired Input Frequency: 1198.125 MHz

RLBAND ON RLBAND ONRADJC ON RADJC ONRCARRIER 1200.025 RCARRIER 1200.025 1198.125RCARRIER #2 1198.125

OR

EXAMPLE 2 (L band input, dual demodulator with RCENTER adjusted manually)Demodulator 1 Desired Input Frequency: 1305.0 MHzDemodulator 2 Desired Input Frequency: 1307.0 MHz

RLBAND ON RLBAND ONRADJC OFF RADJC OFFRCENTER 1306.5 RCENTER 1306.5RCARRIER 1305.0 RCARRIER 1305.0 1307.0RCARRIER #2 1307.0

OR



EXAMPLE 3 (70 MHz input, single demodulator with RCENTER adjusted manually)Demodulator Desired Input Frequency: 68.6 MHz

RLBAND OFFRADJC OFFRCENTER 68.6RCARRIER 68.6

3.3.7.3 Fast Acquisition OperationIn the sweep acquisition mode, programming the centre carrier frequency closer to the actual receivefrequency will reduce the acquisition time. The ROFFSET command is used for this, but only after atleast one acquisition has been made. A query of RROFFSET during the first acquisition determinesthe delta offset between the algebraic sum of RCARRIER and ROFFSET and the actual centrefrequency of the incoming carrier.

For example, once a desired carrier has been acquired, the receive offset value stored in RROFFSETis queried at the remote terminal. From this query, a response of RROFFSET -6200 appears,indicating that the value of the receive carrier is offset by a negative 6200 Hz. This value is enteredusing the command ROFFSET -6200, which will cause the demodulator to begin the acquisition at theRCARRIER frequency minus 6200 Hz.

If the source of the carrier is generated from a highly stable reference oscillator, the value stored inRROFFSET can also be used to adjust the transmitted carrier (TCARRIER) that’s returned to the samesource.

Adjusting the acquisition offset frequency (ROFFSET), is an effective means of reducing the acquisitiontime. However, periodic monitoring of RROFFSET is necessary due to oscillator drift in the satellitechain. The accuracy of ROFFSET (and RCARRIER) is only as good as the last measurement ofRROFFSET used to update ROFFSET.

In the FFT acquisition mode, faster lockup times may be achieved by setting RSWEEP to less than ¼of the symbol rate. As noted, the FFT acquisition mode is most effective at EbN0 values of ≥ 8 dB.

3.3.8 Measuring Acquisition Time of the SL-2048Demodulator

The demodulator in the SL2048 modem contains a down converter that frequency translates the inputfrequency to an intermediate frequency (IF). At this point, the IF is sampled with an analogue to digitalconverter and the individual carriers in the IF are demodulated digitally.

There is an AGC function operating in the down converter. In general, there will be numerous carriersin the sampled IF signal, the AGC function of the down converter has a very narrow bandwidth. TheAGC will respond very slowly to any individual carrier that changes in amplitude. This functionprevents a situation where one carrier is being turned on or off abruptly that changes the level of the

NOTE:ROFFSET is stored in the non-volatile RAM, which utilisesFLASH technology. FLASH memories have a finite number ofwrite cycles (usually around 10,000 cycles) that can beperformed before the integrity of the non-volatile data becomesquestionable. Due to this limitation, it is recommended thatROFFSET be updated only once or twice a day.



entire IF signal. Because the AGC response time is long when measuring the acquisition time, onemust maintain at least one carrier applied to the demodulator input so that the down converter AGCcan function normally. The carrier to be turned off and on during an acquisition test should be within+/-9 dB and within 5 MHz of the carrier that is not switched on/off.

Alternatively, the noise level into the demodulator can be kept at a minimum level to allow the downconverter AGC to operate correctly when no carrier signals are present at it’s input.

3.4 MODEMS WITH REED SOLOMON OPTIONReed Solomon is a block code FEC codec that operates in series (concatenated) with the standardconvolutional Viterbi codec. Reed Solomon, when activated, becomes the outer codec, and Viterbibecomes the inner codec. The Reed Solomon option is a daughter card that can be factory installedon to the existing SL-2048 satellite modems. This option card includes an IESS 308/309scrambler/descrambler, a programmable receive (Doppler) buffer with enhanced clocking, basebandloopback, and an interleaver/deinterleaver between the two codecs to optimise system performance.

Figure 3.2 is a simplified block diagram of the Reed Solomon option card and its constituentcomponents and data paths. Notice that the Reed Solomon can be invoked or bypassed. The receivebuffer can also be turned off, or operate with many different options, as described in Paragraph 3.4.3.

Figure 3.2. Simplified Block Diagram Showing Reed Solomon Option Card

The main features of the Reed Solomon option card is highlighted below:

• Variable data rate from 64 kbps to 2304 kbps, in 1 bps steps• Independent outer encoder/decoder• Intelsat compliant code rates of (126,112), (225,205), (219,201), and (194,178)• Intelsat interleaving/deinterleaving, depth 4• Intelsat 308/309 scrambling options• Internal and external clocking options• Doppler FIFO (first in/first out) buffering from 8 bits to 16 kbits, may be upgraded to 256 kbits• Bi-directional baseband loopback• Fully configurable via modem remote M&C interface• Codec and buffer bypass modes

Reed-SolomonEncoder/

Interleaver

Reed-SolomonDecoder/

De-interleaver

L-Band QPSKModulator

FEC Encoder

L-band QPSKDemodulator

Viterbi Decoder

Synchronous orSelf-Synchronizing

Descrambler

RS-530TerrestrialInterface

Outer Encoder Bypass

Outer Decoder Bypass

To Block Up

Converter

From Block

Down Converter

Receive Data Buffer

IESS Reed-SolomonOuter Codec Option Card SkyLane

Modem


Scrambler

Reed-SolomonEncoder/

Interleaver

Reed-SolomonDecoder/

De-interleaver

L-Band QPSKModulator

FEC Encoder

L-band QPSKDemodulator

Viterbi Decoder


Descrambler



Outer Encoder Bypass

Outer Decoder Bypass

To Block Up

Converter

From Block

Down Converter

From Block

Down Converter

Receive Data Buffer

IESS Reed-SolomonOuter Codec Option Card SkyLane

ModemSkyLaneModem


Scrambler



3.4.1 Transmit Commands/Status with R/S OptionFollowing are the additional modulator control commands available to an operator for changing a singleparameter without having to cycle through a series of items to reach the appropriate function. Thesecommands are in addition to those outlined in Paragraph 3.2.1. (Some of these commands are alsoprovided in Paragraph 3.2.1, but with a different set of parameters, such as TD.)

Refer to Paragraph 3.4.3 for additional transmit clocking options.

If you wish to change the Reed Solomon encoder rate from 126,112, the command TRSRATE 225changes the encoder rate to 225,205. All functions must be followed by ENTER to implement thechange.

Command DescriptionTRSRATE

[126 | 225 | 219 | 194 | OFF]

If this command is entered with no argument, it returns the current outer Reed-Solomon encoder rate setting. To change the outer Reed-Solomon encoder rate,enter the command followed by the desired rate.

Valid values for the outer Reed-Solomon encoder rate are 126 for (126,112), 225 for(225,205), 219 for (219,201), 194 for (194,178) and OFF for (outer encoder bypass)

Example: TRSRATE 126

Outer Reed-Solomon encoder is set to (126,112).

TD [<rate>] If this command is entered with no argument, it returns the current terrestrial datarate in bits per second. To change the terrestrial data rate, enter the commandfollowed by the desired data rate in bits per second. The range of valid values for<rate> is 64000 to 2304000 in integer steps. Note: Actual modulator data rate isTD * Outer Encoder Code Rate. The high-end limit on terrestrial data rate dependson modulator capability. Use the following table to calculate modulator data rate:

Outer Encoder Outer Encoder

TRSRATE Code Rate R-S Overhead (%)

126 126/112 12.500

225 225/205 9.756

219 219/201 8.955

194 194/178 8.989

OFF 1/1 0.0

Example: TD 512000

The terrestrial data rate is set to 512000 bits per second. At Code Rate 126/112,actual modulator data rate is 576000 bits per second.

TXCLK [INT | TT | RT] If this command is entered with no argument, it indicates whether the data timing isgenerated by the modem, DTE, or RT. When TXCLK is INT, the modem generatesthe data timing and provides a data clock on the SCT (or ST) pins of the RS-530interface, see Figure 3.3 (a). When TXCLK is TT, the modulator requires a clock onthe SCTE (or TT) pins of the RS-530 interface at the programmed data rate±100 ppm, see Figure 3.3 (b). When TXCLK is RT, the modem generates the datatiming from RT and provides a data clock on the SCT (or ST) pins of the RS-530interface, see Figure 3.3 (c).The SCT (or ST) clock pins are off even when TXCLK is TT.

Example: TXCLK INT

Transmit timing is generated by modem.

TCINV [ON | OFF] If this command is entered with no argument, it indicates whether the input clockinversion is on or off. When TCINV is off, data is clocked into the modem with therising edge of the clock being used (either SCTE or SCT).

Example: TCINV OFF

The input clock inversion feature is turned off. Data should be valid at the risingedge of the clock.



Command DescriptionTDINV [ON | OFF] If this command is entered with no argument, it indicates whether the data inversion

is on or off. This feature is provided for those systems where it becomes necessaryto invert the data.

Example: TDINV OFF

The output data inversion feature is turned off. The transmitted data will be of thesame polarity as the data input to the modulator.

TMBL [ON | OFF] Must be set to OFF for normal operation. More details of this command areprovided in Paragraph 3.4.3. This command is used for baseband loopback – a testmode.

3.4.2 Receive Commands/Status with R/S OptionFollowing are the additional demodulator control commands available to an operator for changing asingle parameter without having to cycle through a series of items to reach the appropriate function.These commands are in addition to those outlined in Paragraph 3.3.1. (Some of these commands arealso provided in Paragraph 3.3.1, but with a different set of parameters, such as RD.)

These commands do not include those that involve the buffer and the clocking options (with theexception of clock invert/non-invert). Refer to Paragraph 3.4.3 for commands and status of bufferoperation.

If it is desired to change the Reed Solomon decoder rate from 126,112, the command RRSRATE 225changes the encoder rate to 225,205. All functions must be followed by ENTER to implement thechange.

Command DescriptionRRSRATE [126 | 225 | 219| 194 | OFF]

If this command is entered with no argument, it returns the current Reed Solomon coderate. To change the outer Reed-Solomon decoder rate, enter the command followed bythe desired rate. Valid values for the outer Reed-Solomon decoder rate are 126 for(126,112), 225 for (225,205), 219 for (219,201), 194 for (194,178) and OFF for (outerdecoder bypass)

Example: RRSRATE 126

Outer Reed-Solomon decoder is set to (126,112)

RD [<rate>] If this command is entered with no argument, it returns the current terrestrial data rate inbits per second. To change the terrestrial data rate, enter the command followed by thedesired data rate in bits per second. The range of valid values for <rate> is 64000 to2304000 in integer steps. Note: Actual demodulator data rate is RD * Outer DecoderCode Rate. Use the following table to calculate demodulator data rate:

Outer Decoder Outer Decoder

T*RSRATE Code Rate RS Overhead (%)

126 126/112 12.500

225 225/205 9.756

219 219/201 8.955

194 194/178 8.989

OFF 1/1 0.0

Example: RD 512000

The terrestrial data rate is set to 512000 bits per second. At Code Rate 126/112, actualdemodulator data rate is 576000 bits per second.

RRSDESC [OFF | 308 |309]

If this command is entered with no argument, it returns to the current status of thedescrambler. To change the outer codec descrambler setting, enter the commandfollowed by the desired setting. When set to F, the outer codec descrambler is off. Whenset to 8, the outer codec descrambler is in the synchronous mode, as called out in Intelsatspecification IESS-308. When set to 9, the outer codec descrambler is in theself-synchronous mode, as called out in Intelsat specification IESS-309 (VSAT).

Example: RRSDESC 309

The self-synchronising IESS 309 (VSAT) mode used for the outer decoder descrambling.



Command DescriptionRCINV [ON | OFF] If this command is entered with no argument, it indicates whether the clock is inverted or

not. To change the output clock inversion setting, enter command followed by desiredsetting. When set to OFF, the output clock inversion is off. When set to ON, the outputclock inversion is on. This feature is provided for those systems that expect the risingedge of the clock to occur in the middle of the data bit.

Example: RCINV OFF

The output clock inversion feature is turned off. The rising edge of the clock will occur atthe transitions.

RDINV [ON | OFF] If this command is entered with no argument, it indicates whether the data is inverted ornot. To change the output data inversion setting, enter command followed by desiredsetting. When set to OFF, the output data inversion is off. When set to ON, the outputdata inversion is on. This feature is provided for those systems where it becomesnecessary to invert the data.

Example: RDINV OFF

The output data inversion feature is turned off. The output data will be the same polarityas the data input to the modulator.

3.4.3 Receive Buffer Commands/Status for R/S and TurboOptions

The following are the additional demodulator control and commands available to an operator forchanging a single parameter without having to cycle through a series of items to reach the appropriatefunction. They can only be used when either the Reed Solomon outer codec or Turbo codec cards areinstalled. They are not applicable with the optional buffer card, which are addressed in Appendix C ofthis manual.

3.4.3.1 Buffer Control CommandsThese commands include bypassing the buffer, re-centring the buffer, changing the depth of the buffer,and resetting some flags (used for monitoring overflow and underflow conditions).

If you wish to change the buffer depth from 1000 to 250, the command TBD 250, followed by ENTERinvokes the new buffer depth to 250 bits. All functions must be followed by ENTER to implement thechange.

Command DescriptionRBUFFER [OFF | TXCLK |EXT]

If this command is entered with no argument, it returns to the current status of the buffer.To change the receive data buffer clocking option, enter the command followed bydesired setting. When set to OFF, the receive data is not buffered, see Figure 3.4 (a).When set to TXCLK, the receive buffer output is extracted using transmit timing, seeFigure 3.4(b). When set to EXT, the receive buffer output is via the external clock.When set to EXT, data is clocked out of the receive buffer by the external device (DTE)by applying a clock signal to pins 17 & 9, see Figure 3.4 (c).Example: RBUFFER OFFReceive buffer bypass. When set to OFF, receive data is not buffered.

TBC Receive buffer centre. When this command is issued, the buffer is re-centred, and theFIFO flags are reset.

TBD [<depth>] When this command is issued with no argument, the current depth setting is displayed.Changes the receive buffer depth. The range of valid values for <depth> is 0 to 2047.Example: TBD 250Receive buffer depth becomes 250 bits.

TBF Receive buffer flag reset. When this command is issued, the buffer flags are reset, butthe buffer is not re-centred. There is no argument following this command.

TMBL [<ON|OFF>] Modem baseband loopback. When set to ON, the baseband loopback function of themodem is enabled. In this mode, the receive buffer is not operational as a buffer.

Example: TMBL ON

The modem is in baseband loopback. The baseband data from the demodulator isrouted to the modulator.



3.4.3.2 Buffer Status CommandsThe following are the commands to retrieve the status from the Reed Solomon or Turbo card options.

Command DescriptionTBDM Monitors the receive buffer depth.

TBEP Receive buffer FPGA hardware option/revision code.

TBEV Receive buffer events read. This events register works in conjunction with the flag resetcommand (TBF) to detect when an overflow and/or underflow occurs.

Examples of valid responses:

X00 = no overflow or underflow

XX1 = at least one overflow has occurred since the flag was reset

X1X = at least one underflow has occurred since the flag was reset

1XX = at least one buffer re-centring has occurred since the flag was reset

3.4.3.3 Transmit and Receive Clocking OptionsFigures 3.3 and 3.4 provide some preferred clocking options for the SL-2048 modem when it isequipped with either the Reed Solomon outer codec or the Turbo FEC options. Figure 3.3 includesthree clocking options for the transmit (modulator) path, and Figure 3.4 includes three clocking optionsfor the receive (demodulator) path.

Figure 3.3. Preferred Transmit Clocking Options

PLL

NCO

Input

Register

ModulatorBasebandProcessingM&C Command: TXCLK INT

Transmit timing source is from modulator

DTE

ST

TT

SD

DCE

(a)

PLL

NCO

Input

Register

M&C Command: TXCLK TTTransmit timing source is from DTE

DTE

ST

TT

SD

DCE

ModulatorBasebandProcessing

(b)

PLL

NCO

Input

Register

M&C Command: TXCLK RTTransmit timing source is from demodulator

RT (Receive timing)

DTE

ST

TT

SD

DCE


(c)

PLL

NCO

Input

Register



DTE

ST

TT

SD

DCE

(a)

PLL

NCO

Input

Register




DTE

ST

TT

SD

DCE

(a)

PLL

NCO

Input

Register


DTE

ST

TT

SD

DCE


(b)

PLL

NCO

Input

Register


DTE

ST

TT

SD

DCE



(b)

PLL

NCO

Input

Register


RT (Receive timing)

DTE

ST

TT

SD

DCE


(c)

PLL

NCO

Input

Register


RT (Receive timing)

DTE

ST

TT

SD

DCE



(c)



Figure 3.4. Preferred Receive Clocking Options

3.5 MODEMS WITH TURBO OPTIONThe Turbo option card provides an option of using either the onboard Viterbi codec or the Turbo codec.This option can be factory installed on the existing SL-2048 satellite modems.

Turbo is fast becoming the FEC codec of choice, having more coding power and less latency(throughput delay) than the concatenated Viterbi plus Reed Solomon FEC. Turbo increases the codinggain (Eb/No decrease from a reference or raw bit error rate) over standard Viterbi by as much as 4 dBwhen both are operating at ¾ rate. At this time, only ¾ rate Turbo is being offered because of itsoptimal performance.

3.5.1 Transmit Commands/Status with Turbo OptionFollowing are the additional modulator control commands available to an operator for changing asingle parameter without having to cycle through a series of items to reach the appropriate function.These commands are in addition to those outlined in Paragraph 3.2.1. (Some of these commands arealso provided in Paragraph 3.2.1, but with a different set of parameters, such as TRATE.)

Refer to Paragraph 3.4.3 for additional transmit clocking options.If it is desired to change the FEC from Viterbi to Turbo, the TCODE T command followed by ENTERimplements the change. All functions must be followed by ENTER to implement the change.

DemodBasebandProcessing

M&C Command: RBUFFER OFFReceive timing source is from demodulator. Elastic buffer is byp assed.

DTE

RT

RD

Receive Clock

Receive Data

ElasticBuffer

SOSI

DI DO

DCE

(a)

Transmit timing extracts data from buffer and provides DTE with

DTE

RT

RD

Receive Clock

Receive Data

Transmit timing

ElasticBuffer

SOSI

DI DO

DCE

(b)



M&C Command: RBUFFER EXTDTE provides external timing that extracts data from the elastic buffer.

DTE

RT

RD

Receive Clock

Receive Data

ElasticBuffer

SOSI

DI DO

DCE

External clock signalapplied to DCE pins 17 & 9 .

(c)



DTE

RT

RD

Receive Clock

Receive Data

ElasticBuffer

SOSI

DI DO

DCE

(a)




DTE

RT

RD

Receive Clock

Receive Data

ElasticBuffer

SOSI

DI DO

DCE

(a)

M&C Command: RBUFFER TXCLKTransmit timing extracts data from buffer and provides DTE with

DTE

RT

RD

Receive Clock

Receive Data

Transmit timing

ElasticBuffer

SOSI

DI DO

DCE

(b)


Transmit timing extracts data from buffer and provides DTE with transmit timing (TT)

DTE

RT

RD

Receive Clock

Receive Data

Transmit timing

ElasticBuffer

SOSI

DI DO

DCE

(b)





DTE

RT

RD

Receive Clock

Receive Data

ElasticBuffer

SOSI

DI DO

DCE


(c)




DTE

RT

RD

Receive Clock

Receive Data

ElasticBuffer

SOSI

DI DO

DCE


(c)



Command DescriptionTCODE [V | T] If this command is entered with no argument, it indicates the FEC being used. To

change the FEC codec, enter the command followed by the desired FEC. Validvalues for FEC are V for Viterbi and T for Turbo.

Example: TCODE T

The modulator is using the Turbo FEC.

TRATE [½| ¾|7/8] If this command is entered with no argument, it returns the current Viterbi or Turboencoder rate setting. Note that Turbo only operates with ¾ rate: Viterbi operateswith all three. To change the encoder rate, enter the command followed by thedesired encoder rate. Valid values for the Viterbi encoder rate are ½, ¾ and 7/8. Thevalid value for the Turbo encoder rate is ¾.

Example: TRATE ¾

The FEC encoder is set to ¾ rate. The command TCODE determines if it is Viterbior Turbo.

TXCLK [INT | TT | RT] If this command is entered with no argument, it indicates whether the data timing isgenerated by the modem, DTE, or RT. When TXCLK is INT, the modem generatesthe data timing and provides a data clock on the SCT (or ST) pins of the RS-530interface, see Figure 3.3 (a). When TXCLK is TT, the modulator requires a clock onthe SCTE (or TT) pins of the RS-530 interface at the programmed data rate±100 ppm, see Figure 3.3 (b). When TXCLK is RT, the modem generates the datatiming from RT and provides a data clock on the SCT (or ST) pins of the RS-530interface, see Figure 3.3 (c).The SCT (or ST) clock pins are off even when TXCLK is TT.

Example: TXCLK INT

Transmit timing is generated by modem.

TCINV [ON | OFF] If this command is entered with no argument, it indicates whether the input clockinversion is on or off. When TCINV is off, data is clocked into the modem with therising edge of the clock being used (either SCTE or SCT).

Example: TCINV OFF

The input clock inversion feature is turned off. Data should be valid at the risingedge of the clock.

TDINV [ON | OFF] If this command is entered with no argument, it indicates whether the data inversionis on or off. This feature is provided for those systems where it becomes necessaryto invert the data.

Example: TDINV OFF

The output data inversion feature is turned off. The transmitted data will be the samepolarity as the data input to the modulator.

TMBL [ON | OFF] Must be set to OFF for normal operation. More details of this command areprovided in Paragraph 3.4.3. This command is used for baseband loopback – a testmode.

3.5.2 Receive Commands/Status with Turbo OptionFollowing are the additional demodulator control commands available to an operator for changing asingle parameter without having to cycle through a series of items to reach the appropriate function.These commands are in addition to those outlined in Paragraph 3.3.1. (Some of these commands arealso provided in Paragraph 3.3.1, but with a different set of parameters, such as TRATE.)

These commands do not include those that involve the buffer and the clocking options (with theexception of clock invert/non-invert). Refer to Paragraph 3.4.3 for commands and status of bufferoperation.

Command DescriptionRCODE [V | T] If this command is entered with no argument, it indicates the FEC being used. To

change the FEC codec, enter the command followed by the desired FEC. Valid valuesfor FEC are V for Viterbi and T for Turbo.

Example: RCODE T

The demodulator is using the Turbo FEC.



Command DescriptionRRATE [½| ¾|7/8] If this command is entered with no argument, it returns the current Viterbi or Turbo

decoder rate setting. Note that Turbo only operates with ¾ rate: Viterbi operates with allthree. To change the decoder rate, enter the command followed by the desired decoderrate. Valid values for the Viterbi decoder rate are ½, ¾ and 7/8. The valid value for theTurbo decoder rate is ¾.

Example: RRATE ¾

The FEC decoder is set to ¾ rate.

RDINV [ON | OFF] If this command is entered with no argument, it indicates whether the data is inverted ornot. To change the output data inversion setting, enter the command followed by thedesired setting. When set to OFF, the output data inversion is off. When set to ON, theoutput data inversion is on. This feature is provided for those systems where itbecomes necessary to invert the data.

Example: RDINV OFF

The output data inversion feature is turned off. The output data will be at the samepolarity as for the input data into the modulator.

3.6 MODEMS WITH ETHERNET BRIDGE OPTIONThe SL2048 is configured as a 10BaseT Ethernet Bridge designed to operate over an UnshieldedTwisted Pair (UTP) LAN cable, such as would be found in standard telephone wiring. It operatessimilar to the RAD TinyBridgeTM. It is designed to connect directly to a 10BaseT Ethernet port of a PC.It can also be used to connect to other bridges or routers, but may require a crossover cable. It is up tothe installer to review if such a cable is needed to properly route the paired transmit and receive datasignals.

The 10BaseT Ethernet Bridge installed on the SL2048 modem requires that the modulator internalclock (TINT ON or TXCLK INT if the Turbo or Reed/Solomon options are used)) and CTS (TCTS ON)are set to ON. The data rate of the modulator sets the rate at which the data is clocked out of the serialsynchronous port of the bridge.

Connect the Ethernet Bridge to the LAN using the RJ-45 connector on the rear panel of the SL2048. Asketch of the data interface along with the LEDs is shown in Figure 1.2 (c).

The collision LED will flash red whenever a collision occurs on the LAN. The link LED will illuminategreen indicating good link integrity when the bridge is connected to the LAN.

The Bridge performs the bridging function at the MAC (Medium Access Control) level and istransparent to the higher level protocols such as TCP/IP, DECnet, IPX, and operating systems such asNetWare and MS LAN manager. It automatically learns all of the addresses of the LAN it is connectedto. Only broadcasts, multicasts, or frames that are destined for another LAN are forwarded to theWAN.

Filtering and forwarding is performed at the maximum theoretical rate of 15,000 cps. The filtering canbe disabled if required, by asserting the FLTDIS signal. This feature is usefel for extending thephysical limits of a network without incurring the penalties associated with using the repeaters.

The Bridge’s LAN table can store up to 10,000 addresses. The aging mechanism automatically deletesthe entries, if no frames have been received from that station for 5 minutes. The Bridge buffer can hold256 frames, with a throughput latency of 1 frame.

3.6.1 Wan ControllerThe HDLC WAN controller operates in synchronous mode. The synchronous HDLC protocol is a bit-oriented protocol, where data is transmitted into frames. Each frame starts and ends with a flag, whichis the binary sequence of 0111 1110 (0x7E). All frames contain a 16-bit Cyclic Redundancy Check(CRC) field. In synchronous mode, zero-bit insertion is used, to allow the contents of a frame to betransparent. Zero-bit insertion means that a binary 0 is inserted after a succession of five ones within aframe (between flags).



The diagram below shows the structure of the frames transmitted over the WAN. The frameboundaries are defined by flags and all of the frames are transmitted with a 16-bit CRC. The 32-bitLAN CRC is not transmitted over the WAN.

DA SA TYPE DATA CRC

FLAG LAN FRAME FLAG

Enhanced Tinygram Compression increases the data throughput. Valid Ethernet frames have aminimum length 64 bytes. Frames shorter than 64 bytes are padded. With the compression enabled(by asserting the COMPR signal), these padding bytes are stripped off before being transmitted overthe WAN, and repadded while being received on the other side.

Control of the filtering and compression features requiresaccess to the two switches on the Bridge. The switches arefactory set to no filtering and no compression.

The example below shows the difference between a typicalEthernet frame before and after compression.

Before compression:

DA SA Type DATA PADDINGBytes: 6 6 2 20 26

After compression:

DA SA Type DATABytes: 6 6 2 20

3.7 PRESET COMMANDSThe SL-2048 modem has provisions for storing two sets ofprecept configuration commands. These are denoted PRESET 1 and PRESET 2. Each PRESETmemory can store up to 50 configuration commands (transmit and receive data rate, code rate, etc.).These commands are best performed by using the rear panel RS-232 or the RS-485 M&C ports andusing a terminal emulator, such as ProComm or HyperTerminal.

PRESET is ideal in situations where many configuration commands are to be changed while on line,and perhaps these configuration changes are to be operational at a certain day and time period. (If thelocation is a remote link, and the communication channel is via the same satellite link, making onechange to the remote modem may disrupt the channel, and no further commands can be sent.) Theconfiguration commands can be installed in either of the two PRESET memories ahead of time andthen the APPLYP1 or APPLYP2 command can be issued to the modem, and the configurationcommand values can be implemented near simultaneously. Building a PRESET configuration does notaffect the modem operation until APPLYP1 (or 2) have been issued.

3.7.1 Building PRESET CommandsEach set of configuration commands is built by using the DELAY command and is stored in atemporary buffer. This buffer must be cleared prior to building the new commands. Using the DELETEXYZ command clears the buffer. The buffer can be checked that it is empty by using the VIEWcommand. A typical sequence would be as follows:

1. Delete the buffer: DELETE XYZ

2. View the buffer: VIEW

3. Build a set of commands:

DELAY TCAR 1200 Sets the L-band modulator carrier to 1200 MHzDELAY RCAR 1200 Sets the L-band demodulator carrier to 1200 MHzDELAY TRATE 3 Sets the modulator to ¾ rate

1

2

3

4

OFF ON

COMPRESSION

FILTERING

Figure 3.5. Switches forFiltering and Control



DELAY RRATE 3 Sets the demodulator to ¾ rateDELAY TDATA 1024000 Sets the modulator to 1024 kbpsDELAY RDATA 1024000 Sets the demodulator to 1024 kbpsDELAY TSCRAM ON Sets the scrambler to ONDELAY RDESC ON Sets the descrambler to ON

4. View the buffer to check the commands: VIEW

The above is just an example of what commands can be stored in either of the two PRESET memories.If the TCODE and RCODE commands are to be used in a sequence of commands, it is recommendedto put these two at the end of the sequence.

3.7.2 Saving PRESET Configuration CommandsThe commands stored in the DELAY buffer as illustrated above can be saved in either the PRESET 1or PRESET 2 memories. Saving the contents of the DELAY buffer to the PRESET 1 memory isimplemented using the SAVEP1 command. Saving the contents of the DELAY buffer to the PRESET 2memory is implemented using the SAVEP2 command.

3.7.3 Viewing PRESET Configuration CommandsThe commands stored in either the PRESET 1 or PRESET 2 memory can be viewed by executing theVIEWP1 or VIEWP2 commands.

3.7.4 Activating PRESET Configuration CommandsThe commands stored in either the PRESET 1 or PRESET 2 memory can configure the SL-2048modem by executing the APPLYP1 or APPLYP2 commands. Each command in the buffer takes about1 second to execute.

3.8 MONITORING CHASSIS STATUSCommands that are not specific to the Transmitter or Receiver can be executed from J2 on the rearpanel, or from the front panel hand-held terminal port. These commands are summarised in thefollowing table.

3.8.1 Monitor CommandsCommand DescriptionBUC Displays the voltage of the BUC supply as measured on the MSI card. If the BUC power switch is

off, the value will be zero.

CHASSIS Displays the chassis serial number.

EEPROM Displays the part number and version number of the non-volatile memory.

ERASE xyz Erases the 32 characters stored in EEPROM for the NAME function.

EXT Displays the voltage of the external detector at J3. If nothing is connected, the value will be zero.

FIVE Displays the voltage measured on the +5 Volt supply. This reading is accurate to approximately±10%.

HELP Displays an alphabetical list of commands.

INFO Displays information relative to the MSI card that is static.

LED Performs a test of the front panel LEDs.

LNB Displays the voltage of the LNB supply as measured on the MSI card. If the LNB power switch isoff, the value will be zero.

LNBI Displays a value greater than zero if the LNB is drawing current.

MCADD [<address>] Sets the M&C address. A further explanation is provided in Paragraph 3.8.2 RS-485 AddressingMode. The range of valid addresses for <address> is 000-255. The address must be set via theRS-232 ports. The address <000> sets the RS-485 port for a non-addressable terminal mode. Theaddresses <001-255> must uniquely be set for each modem connected to the RS-485 bus.Leading zeros are not required when entering the address.



Command DescriptionNAME [<chars>] When used without an argument, it displays a 32-character string stored in EEPROM. When used

with an argument, it stores the argument in EEPROM. This function is useful to assign an ID to themodem.

POWER [<level>] Sets the desired output power level as measured by the detector in the SierraCom BUC. The rangeof valid values for <level> is 17.0 to 40.0 dBm. This setting has no affect unless tracking is enabled(SBTR).

PN Displays the part number of the multi-serial interface circuit board assembly.

SBACK [<setting>] The gain back off in the BUC may be set from 0 to 15 dB. The setting is non-volatile in the BUC,but it cannot be read back. The user must set it to a known state to be sure of its setting. Therange of valid values for <setting> is from 0 to 15.

Example: SBACK 6

The BUC has a 6-dB attenuator set in its RF path.

SBADD[<address>]

Changes Sierracom BUC address stored in EEPROM. The range of valid values for the <address>is 1 to 15. This address is not currently used by the program and must be set to 1.

SERIAL Displays the serial number of MSI circuit board assembly.

SBPWR Displays the output power of the Sierracom BUC in dBm.

SBTEM Displays the temperature returned by the Sierracom BUC in °C.

SBTR [<ON|OFF>] Enables the PowerTrack feature. The output power of the SL-2048 must first be set so that thepower read from the BUC (SBPWR) is very close to the value of POWER.

SBTX [<ON|OFF>] Sets the Sierracom BUC transmitter on or off. Displays the status of the transmit on/off status bit.

SBPLL Displays the status of the Sierracom BUC PLL lock status bit.

SBRNG [0] Display an indication of whether the tracking range of the PowerTrack system has been exceeded.When entered with the zero argument, resets the indication to OFF.

STATUS Displays information relating to the current status of the MSI card.

TWELVE Displays the voltage measured on the +12 Volt supply. This reading is accurate to approximately±10%.

U300 Displays the version number of the MSI FPGA file.

U300S Displays the status of the MSI FPGA done programming bit.

WIRE [0|2] If this command is entered with no argument, it indicates the current setting of the RS485 portcontrol. This mode should only be set to 2 (two-wire mode for Sierracom BUC control) when aSierraCom BUC is connected at J3 on the rear panel. When set to 0 (four wire terminal mode),commands may be executed at J3 with the proper four-wire connection to a terminal.

Example: WIRE 0

The RS485 port is set to four wire terminal mode.

VER Displays the part number and version number of the internal software.

DEF Sets the modulator and demodulator to defaults as shown in Table 4.1, SL-2048Back-to-Back Parameter Configuration.

These commands only have meaning when the Sierracom BUC is connected to J3 forcommunication via the RS485 port. When J3 is used for connection to the Sierracom BUC, it cannotbe used for M&C via the four-wire RS-485 mode.

3.8.2 RS-485 Addressing ModeTo command a modem on the RS-485 bus, the command must be prefaced with the address 1-255,then a SPACE. Leading zeros for the address are not required. The address and command will not beechoed back to the user. The return prompt after the message is received indicates which modemreplied.

EXAMPLE:<address><command> 023 TBPSK ON [no echoed characters]

Returns:

SL2048 023 ON

SECTION 4. BENCH TESTING THE SL-2048 59


SECTION 4. BENCH TESTING THE SL-2048

4.0 TESTING METHODSThe user can test a single SL-2048 if an external data source such as a BERT is available, or by usingtwo SL-2048 modems back-to-back.

4.1 Testing One SL-20481. Ensure that the DC power for the BUC and LNB is OFF (switches S1 and S2 on the rear panel).

Ensure also that the clock reference for the BUC and LNB is off (TREF OFF and RREF OFF).

2. Connect J1 (IF Output) to J5 (IF Input).

3. Program the modem per Table 4.1 (sets the modem to 64 kbps with ¾ rate coding and Tx/Rx of1200 MHz), or use the “DEF” command to set the defaults. If the unit has the Receive BufferOption installed, then see Appendix C for the Buffer settings.

4. Connect a data source (such as a BERT) to the RS-530 interface using the appropriate cabling(refer to Appendix A for the cabling information).

4.2 Testing Two SL-2048s1. Ensure that the DC power for the BUC and LNB is OFF (switches S1 and S2 on the rear panel).

Ensure also that the clock reference for the BUC and LNB is off (TREF OFF and RREF OFF).

2. Connect J1 (IF Output) to J5 (IF Input).

3. Program the modem per Table 4.1 (sets the modem to 64 kbps with ¾ rate coding, and Tx/Rx of1200 MHz), or use the “DEF” command to set the defaults. If the unit has the Receive BufferOption installed, then see Appendix C for the Buffer settings.

4. Choose one:

a. Connect a data source (such as a BERT) to each of the SL-2048s’ RS-530 interfaces using theappropriate cabling (refer to Appendix A for cabling information). If only one BERT is available and itis desired to test in one direction, then use the TEXT command to turn on the built-in 2047 patterngenerator for the modulator and connect the BERT to the other modem.

b. Alternatively, connect one BERT to one of the SL-2048s, and attach a loopback connector to theother SL-2048 (refer to Table 4.2 for the loopback connector pinout). Ensure that the ModulatorClock parameter on the SL-2048 with the loopback connector is set to External using the TINT OFFcommand in Table 4.1.

Table 4.1. SL-2048 Back-to-Back Parameter Configuration

Parameter Modulator Command Demodulator CommandFrequency TCAR 1200000000 RCAR 1200000000

Data Rate TDATA 64000 RDATA 64000

Code Rate TRATE 3 RRATE 3

Modulator FEC Codec (Viterbi) TVIT ON (Standard)

Differential Encoder / Decoder TDIF ON RDIF ON

Scrambler / Descrambler TSCR ON RDESC ON

BPSK / QPSK TBPS OFF RBPS OFF

Spectral Invert ON / OFF TSPI OFF RSPI OFF

Scrambler Algorithm TCCI ON RCCI ON

Transmit Power Level TLEV -40

Modulator ON / OFF TMOD ON

60 SECTION 4. BENCH TESTING THE SL-2048


Parameter Modulator Command Demodulator CommandModulator Clock INT / EXT Standard

TINT ON (No loopback connector)Turbo option:TXCLK INT

Clock Invert ON / OFF TCINV OFF RCINV OFF

Data Invert ON / OFF TDINV OFF RDINV OFF

Receiver Sweep Range RSWE 24000

Receive Buffer RBUFFER OFF (Turbo option )See Appendix C for Receive BufferConfigurations.

Code Mode TCODE TURBO (Turbo option) RCODE TURBO (Turbo option)Loopback TMBL OFF

Table 4.2. RS-530 Loopback Connector

Pin Signal Pin Signal2 SD-A 3 RD-A

14 SD-B 16 RD-B

17 RT-A 24 TT-A

9 RT-A 11 TT-B

Note: RS-530 loopback connector is a DB-25 male connector.

APPENDIX A. CABLES AND PINOUTS 61


APPENDIX A. CABLES AND PINOUTS

A.1 RS-442/449 TO RS-530 ADAPTER CABLEUsing a SkyLane SL-2048 with devices that have an RS-422/RS-449 interface (such as a BER tester)requires an adapter cable. Although the RS-530 and RS-422/RS-449 interfaces are electricallyidentical, they have different connectors. Therefore, use a cable with the pinout listed in Table A.1.

Table A.1. RS-422/RS-449 to RS-530 Adapter Cable Pinout

RS-422/RS-449 Pin RS-422/RS-449 Signal Source RS-530 PinP1-17 TT-A DTE P2-24

P1-35 TT-B DTE P2-11

P1-4 SD-A DTE P2-2

P1-22 SD-B DTE P2-14

P1-5 ST-A DCE P2-15

P1-23 ST-B DCE P2-12

P1-7 RS-A DTE P2-4

P1-25 RS-B DTE P2-19

P1-9 CS-A DCE P2-5

P1-27 CS-B DCE P2-13

P1-1 Shield P2-1

P1-19 Signal Ground P2-7

P1-13 RR-A DCE P2-8

P1-31 RR-B DCE P2-10

P1-11 DM-A DCE P2-6

P1-29 DM-B DCE P2-22

P1-6 RD-A DCE P2-3

P1-24 RD-B DCE P2-16

P1-8 RT-A DCE P2-17

P1-26 RT-B DCE P2-9

Notes:P1 is a male DB-37 connectorP2 is a male DB-25 connector.Wire A/B pairs using # 28 AWG twisted pair.

A.2 RS-442/449 TO RS-530 Y-CABLEIf a Y-type cable is required to go from RS-422/RS-449 to RS-530, use the pinout listed in Table A.2.

Table A.2. RS-422/RS-449 to RS-530 Y-Cable Pinout

RS-422/RS-449 Pin RS-422/RS-449 Signal Source RS-530 PinP1-17 TT-A DTE P2-24

P1-35 TT-B DTE P2-11

P1-4 SD-A DTE P2-2

P1-22 SD-B DTE P2-14

P1-5 ST-A DCE P2-15

P1-23 ST-B DCE P2-12

P1-7 RS-A DTE P2-4

62 APPENDIX A. CABLES AND PINOUTS


RS-422/RS-449 Pin RS-422/RS-449 Signal Source RS-530 PinP1-25 RS-B DTE P2-19

P1-9 CS-A DCE P2-5

P1-27 CS-B DCE P2-13

P1-1 Shield P2-1

P1-1 Shield P3-1



P1-13 RR-A DCE P3-8

P1-31 RR-B DCE P3-10

P1-11 DM-A DCE P3-6

P1-29 DM-B DCE P3-22

P1-6 RD-A DCE P3-3

P1-24 RD-B DCE P3-16

P1-8 RT-A DCE P3-17

P1-26 RT-B DCE P3-9

Notes:P1 is a male DB-37 connector that connects to the BERT.P2 is a male DB-25 connector that connects to the Modulator.P3 is a male DB-25 connector that connects to the Demodulator.Wire A/B pairs using # 28 AWG twisted pair.

A.3 RS-530 DATA INTERFACE PINOUTThe 25-pin D connector labelled TX/RX DATA RS-530 on the rear panel has the pinout listed in TableA.3.

Table A.3. TX/RX Data Pinout

DB-25 PinNumber

RS-530Name

CommonName Description DIRECTION

Pin 2 BA-A TD-A Transmit Data (A) To Modem

Pin 14 BA-B TD-B Transmit Data (B) To Modem

Pin 24 DA-A SCTE-A Transmit Signal Element Timing DTE (A) To Modem

Pin 11 DA-B SCTE-B Transmit Signal Element Timing DTE (B) To Modem

Pin 15 DB-A SCT-A Transmit Signal Element Timing DCE (A) From Modem

Pin 12 DB-B SCT-B Transmit Signal Element Timing DCE (B) From Modem

Pin 5 CB-A CTS-A Clear to Send (A) From Modem

Pin 13 CB-B CTS-B Clear to Send (B) From Modem

Pin 4 CA-A RTS-A Request to Send (A) To Modem

Pin 19 CA-B RTS-B Request to Send (B) To Modem

Pin 3 BB-A RD-A Receive Data (A) From Modem

Pin 16 BB-B RD-B Receive Data (B) From Modem

Pin 17 DD-A RT-A Received Signal Element Timing DCE (A) From Modem

Pin 9 DD-B RT-B Received Signal Element Timing DCE (B) From Modem

Pin 6 CC-A DCE Ready-A DCE Ready-A From Modem

Pin 22 CC-B DCE Ready-B DCE Ready-B From Modem

Pin 8 CF-A RLSD-A Received Line Signal Detect (A) From Modem

Pin 10 CF-B RLSD-B Received Line Signal Detect (B) From Modem

Pin 7 GND GND GND

Pin 25 TM -12 V Test Mode From Modem

Pin 1 SHIELD SHIELD GND From Modem



A.4 RJ-45 ETHERNET CONNECTOR PINOUTThe 10BaseT Ethernet connection utilises a RJ-45 connector, as shown in Table A.4. Figure A.1depicts the arrangement of the pins, looking into the connector.

Table A.4. RJ-45 Connector Pinout

RJ-45 PinNumber Description Wire Colour

CodesCrossoverCable Pins

1 TX + White w/Orange 3

2 TX - Orange 6

3 RX + White w/Green 1

4 Blue

5 White w/Blue

6 RX - Green 2

7 White w/Brown

8 Brown

Figure A.1. RJ-45 Connector Showing Pinout

A.5 RS-232 CONNECTOR PINOUTTable A.5 lists the pinout of the 9-pin D connector, J2, on the rear panel labelled M&C RS-232.

Table A.5. RS-232 Connector Pinout

DB-9 Pin Number DescriptionPin 1 Not Used

Pin 2 Tx Data

Pin 3 Rx Data

Pin 4 Not Used

Pin 5 Ground

Pin 6 Not Used

Pin 7 Not Used

Pin 8 Not Used

Pin 9 +5 VDC @ 100 mA

1 81 8



A.6 RS-232 NULL MODEM CABLE ASSEMBLYTable A.6 lists the pinouts of a cable assembly that can connect the SL-2048 M&C port to anotherRS232 DCE port. The loopback handshaking listed is not required for the SL-2048 modem, but maybe required for the other port.

Table A.6. RS-232 Null Cable Connector Pinout

DB-9 Pin Number Description SL-2048 Pin NumberPin 1 RSLD to Pin 4 and 6

Pin 2 TX/RX Data Pin 3

Pin 3 RX/TX Data Pin 2

Pin 4 DTR to Pin 1 and 6

Pin 5 Ground Pin 5

Pin 6 DSR to Pin 1 and 4

Pin 7 RTS to Pin 8

Pin 8 CTS to Pin 7

Pin 9 Not Used

A.7 RS-485 CONNECTOR PINOUTTable A.7 lists the pinout of the 9-pin D connector, J3, on the rear panel labelled M&C RS-485.

Table A.7. RS-485 Connector Pinout

DB-9 Pin Number DescriptionPin 1 Signal Ground

Pin 2 Power Detector -

Pin 3 Not Used

Pin 4 RS-485 TX +

Pin 5 RS-485 TX -

Pin 6 Power detector +

Pin 7 Not Used

Pin 8*** RS-485 RX +

Pin 9*** RS-485 RX -

*** Pins 8 and 9 are for 2-wire operation. Pins 4, 5, 8, and 9 are for 4-wire operation.

A.8 RJ-11 TO 9-PIN ADAPTER CABLEIf it is desired to connect a hand-held terminal to the Monitor and Control connector on the rear panellabelled RS-232, use an adapter cable. Adapter cables are readily available, but must be individuallywired. Follow the pinout listed in Table A.8. Figure A.2 shows the pinout for the RJ-11 connector,looking into the connector.

Table A.8. RJ-11 to 9-Pin Connector Cable Pinout

D Connector Signal RJ-11 ConnectorPin 1 Common Pin 5

Pin 2 Term Data IN Pin 3

Pin 3 Term Data OUT Pin 2



D Connector Signal RJ-11 ConnectorPin 5 Ground Pin 1

Pin 6 Not Used Pin 4

Pin 9 + 5VDC @ 100 mA Pin 6

Figure A.2. RJ-11 Connector Showing Pinout

A.9 BUC/MODEM CABLING REQUIREMENTSTable A.9 describes the cable assembly necessary to establish communications from the SL-2048modem and the SierraCom BUC. The 9-pin D connector is a male and is not supplied. The 17-pincircular connector is a female and is supplied with the BUCs.

Table A.9. Cable Assembly Pinout for SL-2048 Modem and SierraCom Ku Band BUC

9 PIN D CONNECTOR 17 PIN CIRCULAR CONNECTOR SIGNAL DESCRIPTIONPin 1 Pin M Signal Ground

Pin 8 Pin D RS485 (+)

Pin 9 Pin C RS485 (-)

A.10 L-BAND TRANSMIT CABLEThe recommended cable used to connect the modulator output to the BUC is available from TimesMicrowave Systems. The part number of the bulk cable is LMR-600DB. The assembly number of afinished cable is AE50520-XXX where XXX specifies the cable length in feet. This cable has maletype-N connectors at each end. The cable and its connectors have an impedance of 50 Ω. SeeSection 2, Figure 2.5 for attenuation characteristics.

A.11 L-BAND RECEIVE CABLEThere are many types of coaxial cables that can be used to connect the LNB/BDC to the demodulatorinput. The appropriate cable is dependent on many factors, including the gain in the LNB andBDC/LNA, and the distance between the LNB or BDC and the input to the demodulator. The cable andits connectors should have impedance of 75 Ω.

One such cable is the 5916 or 5916R cable supplied by CommScope. It is an RG11 type cable thathas an RF loss of 4.4 dB @ 950 MHz and 6.33 dB @ 2050 MHz per 100 ft, and a DC resistance of1.5 Ω per 100 ft. Connectors for this cable are available from Gilbert Engineering.

1 6




APPENDIX B. S/N AND Eb/N0 VALUES 67


APPENDIX B. S/N AND Eb/N0 VALUES

Table B.1 lists values for S/N and Eb/N0 (QPSK) based on (S+N)/N values.

Table B.1. S/N and Eb/N0 Values

(dB) Code Rate ½ Code Rate ¾ Code Rate 7/8(S+N)/N S/N Eb/N0 S/N Eb/N0 S/N Eb/N0

4.0 1.8 1.8 1.8 0.0 1.8 --

4.5 2.6 2.6 2.6 0.8 2.6 0.2

5.0 3.3 3.3 3.3 1.6 3.3 0.9

5.5 4.1 4.1 4.1 2.3 4.1 1.7

6.0 4.7 4.7 4.7 3.0 4.7 2.3

6.5 5.4 5.4 5.4 3.6 5.4 3.0

7.0 6.0 6.0 6.0 4.3 6.0 3.6

7.5 6.6 6.6 6.6 4.9 6.6 4.2

8.0 7.3 7.3 7.3 5.5 7.3 4.9

8.5 7.8 7.8 7.8 6.1 7.8 5.4

9.0 8.4 8.4 8.4 6.7 8.4 6.0

9.5 9.0 9.0 9.0 7.2 9.0 6.6

10.0 9.5 9.5 9.5 7.8 9.5 7.1

10.5 10.1 10.1 10.1 8.3 10.1 7.7

11.0 10.6 10.6 10.6 8.9 10.6 8.2

11.5 11.2 11.2 11.2 9.4 11.2 8.8

12.0 11.7 11.7 11.7 10.0 11.7 9.3

12.5 12.2 12.2 12.2 10.5 12.2 9.8

13.0 12.8 12.8 12.8 11.0 12.8 10.4

13.5 13.3 13.3 13.3 11.5 13.3 10.9

14.0 13.8 13.8 13.8 12.1 13.8 11.4

14.5 14.3 14.3 14.3 12.6 14.3 11.9

15.0 14.9 14.9 14.9 13.1 14.9 12.5

15.5 15.4 15.4 15.4 13.6 15.4 13.0

16.0 15.9 15.9 15.9 14.1 15.9 13.5

16.5 16.4 16.4 16.4 14.6 16.4 14.0

17.0 16.9 16.9 16.9 15.2 16.9 14.5

17.5 17.4 17.4 17.4 15.7 17.4 15.0

18.0 17.9 17.9 17.9 16.2 17.9 15.5

18.5 18.4 18.4 18.4 16.7 18.4 16.0

19.0 18.9 18.9 18.9 17.2 18.9 16.5

19.5 19.5 19.5 19.5 17.7 19.5 17.1

20.0 20.0 20.0 20.0 18.2 20.0 17.6




APPENDIX C. RECEIVE BUFFER CARD OPTION 69


APPENDIX C. RECEIVE BUFFER CARD OPTIONThe purpose of this option card is to enhance the existing SL-2048 modem with receive bufferingcapability. This buffer can be used as a Doppler buffer, or possibly to limit the slip between twodissimilar clocks. Additional secondary features include:

DCE line protection,

Baseband loopback,

Upgrades the FIFO depth up to 256K, and

Enhanced clocking options.

C.1 FUNCTIONAL DESCRIPTIONThe heart of the receive buffer option is an asynchronous dual port FIFO (First In, First Out register).The card is actually installed on the modulator card, although the receive buffer is primarily intended foruse by the demodulator. Two special headers (J100 and J101) on the modulator card extend powerand programming information to the receive buffer card, and transfer receive data through the FIFO.

Other than initial configuration, basic FIFO management does not require microprocessor intervention.Once the FIFO has been programmed to its ½ full setting, the FIFO and its surrounding circuitrymaintain the setting (even on power up, although in a reset state). It automatically is re-centred(to ½ full) upon an under or over flow condition.

FIFO features include:

Ability to store large amounts of data,

Programmable depth,

Auto re-centring upon under/over flow,

Pointer gauge,

Reset command, and

Internal/external clocking modes.

The standard buffer size is 0 to 16 kbps (half full), or 0 to 32 kbps (full), which is considered an optimalrange for data rates up to 512 kbps. However, other buffer sizes can be ordered upon request. TableC.1 provides the buffer standard and options, along with the maximum number of bytes and bits theFIFO will hold at ½ full and includes the throughput delay at 64 kbps and 512 kbps when that particularFIFO is set to its maximum.

Table C.1 Buffer Depth Options using Alternate IDT FIFO Devices.

Mfr. Part # Organisation ½ Full ByteSize

½ Full BitSize

64 kbps ½Full

(Seconds)

512 kbps ½Full

(Seconds)IDT7203 2,048 x 9 1 Kbytes 8 kbits 125 ms 15.63 ms

IDT72041 4,096 x 9 2 Kbytes 16 kbits 250 ms 31.25 ms

IDT7205 8,192 x 9 4 Kbytes 32 kbits 500 ms 62.50 ms

IDT7206 16,384 x 9 8 Kbytes 64 kbits 1 S 125.00 ms



1 Standard Buffer Size.

70 APPENDIX C. RECEIVE BUFFER CARD OPTION


Programming of the Doppler buffer card include changing its depth, turning it on or off (bypass),re-centring the buffer and changing its clocking options. Another command also allows the receiveddata to be internally looped back to the transmit data (a test condition). The latter function is ideal fordoing the distant end BER testing, whereby the distant end BERT transmits a test pattern to thenear-end modem, is looped back, and retransmitted to the distant end BERT.

Note: The programmable loopback function is at TTL levels, and therefore does not test the interfaceline drivers.

C.2 SIMPLIFIED THEORY OF OPERATIONThis section describes, in simplified form, the buffer operation, and the various (enhanced) clockingoptions that are available from the programming menus. Figure C.1 provides a functional blockdiagram of the FIFO and the associated circuitry. It does not show the loopback function, which wouldhave further complicated the drawing.

During normal operation, a ribbon cable passes the RS-422 demodulator clock and data to the ReceiveBuffer option card. Line receivers (not shown in the diagram) on the card convert the signals into TTLvoltage levels. FIFO (FPGA) circuitry loads the eight-bit parallel data into the FIFO from the receiveserial demodulator data. FPGA circuitry then extracts the eight-bit parallel data from the FIFO andconverts it back into the serial data that is derived from either Tx or external timing. Line drivers thenconvert the TTL clock and data to RS-422 differential signals (RT and RD, respectively).

There are many ways of clocking the data into the modulator, and out of the receive buffer (FIFO).These include the following:

Modulator OutputLocal Tx–generated by a Numerically Controlled Oscillator (NCO) on the modulator board.This is the configuration when the modulator creates the free running transmit clock.

TT or RT_EXT – TT is the Terminal Timing from an external source. RT is from the clock thatis generated from the extracted data to the demodulator. TT is used when an external sourcecreates the transmit clock. RT_EXT is used in tail-end circuits or where the receive data isfrom a highly stable clock source.

Demodulator (Receive Buffer) OutputLocal Tx – extracted from the receive data into the demodulator. This mode is where themodulator free-running NCO is used as the clock source to clock out the receive data. This isone way of using the receive buffer to remove Doppler effects from the diurnal satellitemovements.

TT or RT_EXT – TT is used when an external source, such as a station clock, is used to clockdata out of the receive buffer. This is another way of using the receive buffer to removeDoppler effects from the diurnal satellite movements. RT_EXT is the extracted clock from thereceived data generated by the demodulator. This mode will not remove the Doppler effects.

Remote RT – This is a mode where the Receive Timing (RT) is not generated by the modem,but instead is provided by an external source. If available, this mode could be used to removeDoppler effects from the diurnal satellite movements.

Receive Buffer Bypass – bypasses the receive buffer (FIFO) and the clock and data from thedemodulator is directly sent to RT and RD, respectively. In this mode, all of the otherdemodulator clocking options is inhibited.

There are other functions performed by the receive buffer (FIFO) and associated circuitry that is usefulin understanding the buffer operation (circuitry is not shown in the diagram):

A FIFO Depth Counter continuously monitors the depth and detects when a buffer overflowoccurs. It uses the parallel FIFO bit eight, when the count exceeds the preset threshold set by

APPENDIX C. RECEIVE BUFFER CARD OPTION 71


the M&C (TBD [<depth>]). Exceeding the count causes the FIFO to be reset and re-centred.This count is available for viewing through the M&C (TBDM).

An Async FIFO continuously monitors the FIFO Depth Counter when the count reaches zero,which is the detection of an underflow condition. This causes the buffer to be reset andre-centred.

Figure C.1. Simplified Logic Diagram of Enhanced Receive Buffer

The Reset Logic detects and responds to reset the conditions. Reset from the M&C (TBC),FIFO Depth Counter overflow or Async FIFO underflow will trigger a reset, causing the bufferto re-centre. Upon any reset condition, the Reset Logic will purge the FIFO contents andinitiate the Programmable FIFO Extraction Hold-off Counter.

The purpose of the Programmable FIFO Extraction Hold-off Counter is to re-centre thebuffer. The output from the Reset Logic suspends the reading from the purged FIFO basedupon the preset count. The FIFO is permitted to half fill while the reading is suspended.

C.3 BUFFER COMMANDS AND STATUSCommands and status information related to the receive buffer are summarised in the following tables.These commands are in addition to those provided by the basic modem, as described in Section 3.Although the receive buffer is associated with the demodulator, a “T” rather than an “R” preface is usedin all of the programming commands for the receive buffer due to receiving its programming from themodulator (HC11) bus.

FIFOSO

Q

SI

D

/OE

1

0

RT_EXTUsing RT pins as input

Using Tx = 0

DEMOD

MODULATOR

1

0

1

0

1

0

1

0

Tx ClkInt = 1,Ext= 0

Rx Clock

Rx Data

Tx Clock

Tx Data

1

0

NCO

FIFO_BYPASSEnable Bypass =

P1JumperOption

1

0

RT>ST

TX TimingLocal Internal (NCO)Local External (TT or RT_EXT)

RX TimingLocal Internal (NCO)Local External (TT or RT_EXT)Remote (RT)

RTBA

RDBA

SDBA

TTBA

STBA

DCE"D" 25 pin

female

12

15

11

24

14

2

9

17

16

3

RTSBA

CTSBA

19

4

13

5

Fault

1 = Enable

72 APPENDIX C. RECEIVE BUFFER CARD OPTION


C.3.1 Receive Buffer CommandsThese commands include: bypassing the buffer, re-centring the buffer, changing the depth of thebuffer, resetting some flags (used for monitoring overflow and underflow conditions), and the variousclocking options as was described earlier in this appendix.

Command DescriptionTBB [<ON|OFF>] Receive buffer bypass. When set to ON, receive data is not buffered.

TBC Receive buffer centre. When this command is issued, the buffer is re-centred, and theFIFO flags are reset.

TBD [<depth>] Change the receive buffer depth. The range of valid values for the <depth> is 0 to 2047.When this command is issued with no argument, the current depth setting is displayed.

TBF Receive buffer flag reset. When this command is issued, the buffer flags are reset, butthe buffer is not re-centred.

TBOCE [<ON|OFF>] Receive buffer output clock external. When set to ON, the data is clocked out of thereceive buffer by the external device (DTE) by applying a clock signal to pins 17 & 9.

TBOCT [<ON|OFF>] Receive buffer output clock transmit. When set to ON, the clock for the modulator isused to clock data out of the receive buffer.

TMBL [<ON|OFF>] Modem baseband loopback. When set to ON, the baseband loopback function of themodem is enabled. In this mode, the receive buffer is not operational as a buffer.

TRCLK [<ON|OFF>] Receive clock sources the transmit clock. When set to ON, the clock for the modulator issourced by the receive clock.

C.3.2 Receive Buffer StatusThese are the commands for retrieving the status from the card.

Command DescriptionTBDM Monitors the receive buffer depth.

TBEP Receive buffer FPGA hardware option/revision code.

Prototype 1 – Set to 1.

TBEV Receive buffer events read. This events register works in conjunction with the flag resetcommand (TBF) to detect when an overflow and/or an underflow occurs.

X00 = no overflow or underflow

xx1 = at least one overflow has occurred since the flag was reset

x1x = at least one underflow has occurred since the flag was reset

1xx = at least one buffer re-centring has occurred since the flag was reset

TBPN Receive buffer hardware option/revision code.

Prototype 1 – Set to 1.

TBSTAT This command will return to the state of all of the Receive Buffer commands.

C.3.3 Receive Buffer Standard Configuration SettingsThese are the standard receive buffer configuration settings from the card.

Parameter Command SettingBuffer Bypass TBB OFF

Buffer Re-centre TBC As Required

Buffer Depth TBD 1024

External Receive Buffer Clock TBOCE OFF

Internal receive Buffer Clock TBOCT ON

Baseband Loopback TMBL OFF

Transmit Clock Selection TRCLK OFF for Internal Clock, ON for External Clock

Buffer Flag Reset TBF As Required

APPENDIX D. SL-2048 OPERATION WITH SIERRACOM BUC AND ADVANTECH SSPB 73


APPENDIX D. SL-2048 OPERATION WITHSIERRACOM BUC AND ADVANTECH SSPB

The purpose of this Appendix is to provide the procedures for operating the SL-2048 satellite modemwith the SierraCom BUC and the Advantech SSPB. Please read this entire document prior to handlingthe hardware. Carefully follow each step in the correct sequential order. If any problems occur whengetting started, please consult with SPL/ACT Wireless at 480-784-4646.

While going through the following procedure, refer to the SL-2048, the SierraCom or Advantechmanuals and Figure D.1. Test Diagram 1.

D.1 BUC INTERFACE CONNECTIONS1. Connect BUC WR75 waveguide output to a suitable load. The Ortho Mode Transducer (OMT)

properly mounted to antenna or power attenuator will qualify as a suitable load.

2. Place BUC power SW1 in the OFF position.

3. Connect SL-2048 (J1) to BUC (IFL) using low-loss 50-Ohm cable with type N (male) connectors ateach end. Cable loss must not exceed 12.5 dB at 1500 MHz. Cable centre conductor dcresistance (end to end) must not exceed 0.5 Ohms. For cable runs up to 100 meters, useLMR-600or equivalent.

4. Connect SL-2048 (J3) to BUC (RS-485) using twisted pair cable. The connector supplied with theSierraCom BUC is used at one end and a 9-pin male D connector at the other.

D.2 LNB INTERFACE CONNECTIONS1. Connect LNB WR75 waveguide input to OMT output.

2. Place LNB power SW2 in the OFF position.

3. Connect LNB output to SL-2048 (J5) using low-loss 75-Ohm cable with type F (male) connectors ateach end. Cable loss must not exceed 25 dB at 1500 MHz.

D.3 RS-232 M&C INTERFACE CONNECTIONSConnect M&C RS-232 (J2) interface to a PC with available RS-232 interface. An optional hand-heldterminal may be used at the front panel M&C Interface. Refer to SL-2048 manual for more details.

D.4 SL-2048 MODEM CONFIGURATION1. Refer to SL-2048 manual regarding the setting of the modulator parameters.

2. Use the following formula to determine the modulator IF frequency based from upon the transmitfrequency: (BUC TX frequency) - (BUC LO 13.05 GHz) = Modulator IF carrier frequency.

3. Example for the desired TX frequency of 14.250 GHz: 14.250 – 13.050 = 1200 MHz.

4. Refer to SL-2048 manual regarding the setting of demodulator parameters.

5. Use the following formula to determine demodulator IF frequency based upon the receivefrequency from the satellite: RX frequency – LNB LO frequency = IF

D.5 TX CARRIER ENABLE1. Double-check modulator IF carrier frequency to insure proper TX frequency.

2. Determine desired TX output level from BUC.

3. Determine modulator output level based upon following formula:(TX BUC dBm) – (IF to RF BUC gain dB)- (Cable Loss dB) = Modulator carrier level.

74 APPENDIX D. SL-2048 OPERATION WITH SIERRACOM BUC AND ADVANTECH SSPB


Example: 4 Watts = +36 dBm, BUC gain = 56 dB, cable loss 6 dB.36 dBm – 56 dB – 6 dB = -26 dBm

4. As in the above example, set modulator output level using M&C command “TLEVEL –26”.

5. Double-check BUC output for proper termination.

6. Using M&C command “TREF ON”, to enable 10 MHz.

7. Set SL-2048 BUC power switch SW1 in the ON position.

8. Use M&C command “SBTX ON”, to enable the BUC transmitter. At this point, the BUC should betransmitting.

9. To check actual TX power, use M&C command “SBPWR” to read detected TX power measured atBUC output. Adjust modulator output to obtain the desired TX output power.

D.6 RX CARRIER ACQUISITION1. Place LNB power switch SW2 in the ON position.

2. Use M&C command “RSPI OFF”, to disable the receive Spectrum Invert feature. See SL-2048 formore details.

3. Use M&C command “RSW 32”, to enable demodulator sweep at +/- 32 kHz.

4. To check for carrier acquisition, use SL-2048 front panel RX Lock indicator to detect lock.

SierraCom BUC or Advantech

SSPB

J1 J5

M&C RS485J3

M&C RS-232J2

LNB

IBM Compatible

M&C Terminal Interface

Caution: +24 or +48 VDC is present on J1 center conductor. Use BUC power switch (SW1) or DC block to prevent damage to test equipment.

Do not use thisLNB connector.

RF Output

RF Input

RS-530

TX/RX DATAP1

AC Power

SW2

LNBPWR

SW1

BUCPWR

SL-2048 Rear Panel

75 Ohm Coax 950 - 1450 MHzConnectors Type F(female)

50 Ohm Coax 950 - 1450 MHzConnectors Type N(male)

L Band ConnectorType N (female)

RS-485 Connector(Provided)

Caution: RF Output must be properly terminated to prevent damage to BUC/SSPB.

Figure D1. Test Diagram 1

Refer to SL-2048 and BUC/SSPBManuals for Pin Assignments

Caution: +20 VDC is present on J5 center conductor. Use LNB power switch (SW2) or DC block to prevent damage to test equipment.

RS-232 M&CInterface. ReferTo SL-2048Manual for Installation andOperation.

SierraCom BUC or Advantech

SSPB

J1 J5

M&C RS485J3

M&C RS-232J2

LNB

IBM CompatibleIBM Compatible

M&C Terminal Interface

Caution: +24 or +48 VDC is present on J1 center conductor. Use BUC power switch (SW1) or DC block to prevent damage to test equipment.

Do not use thisLNB connector.

RF Output

RF Input

RS-530

TX/RX DATAP1

AC Power

SW2

LNBPWR

SW1

BUCPWR

SL-2048 Rear Panel

75 Ohm Coax 950 - 1450 MHzConnectors Type F(female)

50 Ohm Coax 950 - 1450 MHzConnectors Type N(male)

L Band ConnectorType N (female)

RS-485 Connector(Provided)

Caution: RF Output must be properly terminated to prevent damage to BUC/SSPB.

Figure D1. Test Diagram 1

Refer to SL-2048 and BUC/SSPBManuals for Pin Assignments

Caution: +20 VDC is present on J5 center conductor. Use LNB power switch (SW2) or DC block to prevent damage to test equipment.

RS-232 M&CInterface. ReferTo SL-2048Manual for Installation andOperation.

APPENDIX E. COMMANDS NO LONGER SUPPORTED BY THE DEMODULATOR 75


APPENDIX E. COMMANDS NO LONGERSUPPORTED BY THE DEMODULATOR

1. For demodulator software version C1.0 and higher

Command DescriptionRGAIN [<setting>] Refer to the Paragraph 3.3.8 Gain Configuration for additional information regarding this

command. If this command is entered with no argument, it returns the current setting of thedown converter gain in dB. To change the gain, enter the command followed by the desiredamount gain in dB. The range of valid values for <setting> is 5 to 70 dB, in increments of1 dB.

Example: RGAIN 31

The gain of the L-band down converter is set to 31 dB.

2. For demodulator software version C2.0 and higher

Command DescriptionRLCARRIER [<freq>] If this command is entered with no argument, it returns the current L-band input frequency

in Hz of the demodulator. To change the input frequency, enter the command followed bythe desired L-band input frequency in Hz. The range of valid values for <frequency> is950000000 to 2050000000, in 100 Hz steps.

Example: RLCARRIER 950000000

The L-band input frequency for the demodulator is set to 950 MHz.

R70CARRIER

[<frequency>]

Normally this command will be used when using the 70 MHz input. If this command isentered with no argument, it returns the current carrier frequency of the demodulator in Hz.To change the frequency, enter the command followed by the desired frequency in Hz. Therange of valid values for <frequency> is 52000000 to 88000000, in 1 Hz steps.

Example: R70CARRIER 70000000

The centre frequency of the demodulator is set to 70 MHz.R70CARRIER [<freq1>] [<freq2>]

If this command is entered with no argument, it returns the current carrier frequency ofdemodulator 1and 2 in Hz. To change the frequency, enter the command followed by thedesired frequency in Hz. The range of valid values for the <frequency> is 52000000 to88000000, in 1 Hz steps. The frequency for demodulator 1 must be no more than5 MHz minus the arithmetic mean of the symbol rates of both carriers from the frequency ofdemodulator 2.

Example: R70CARRIER 70000000 72000000

The centre frequency of demodulator 1 is set to 70 MHz and the centre frequency ofdemodulator 2 is set to 72 MHz.

RLCARRIER[<freq1>] [<freq2>]

If this command is entered with no argument, it returns to the current carrier frequency of thedemodulators 1and 2 in Hz. To change the frequency, enter the command followed by thedesired frequency in Hz. The range of valid values for <frequency> is 950000000 to2050000000, in 100 Hz steps. The frequency for demodulator 1 must not exceed 5 MHzminus the arithmetic mean of the symbol rates of both carriers from the frequency ofdemodulator 2.

Example: RLCARRIER 950000000 955000000

The L-band input frequency for demodulator 1 is set to 950 MHz and for demodulator 2, 955MHz.

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SL2048 Manual RevF

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