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DEPT. OF ELECTRONICS AND AUTOMATION
NALCO E&A
(A Govt. of India Enterprise)
RISHIJIT PANIGRAHI1041110289ECE E
4TH
YEAR
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NALCO OVERVIEW
Incorporated in 1981ISO 9002 (QMS)
ISO14001(EMS).
Miniratna status.
Largest integrated
Aluminium plant in Asia
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Units
ALUMINAREFINERYBAUXITEMINES
SMELTER CAPTIVE POWER PLANT HOME
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BAUXITE MINES
Koraput Panchpatmalihills
48 ltpa
Open cast mining
( Computerised mine planning)Gibsite bauxite (Al2O3.3H20)
14.6 km long single flight, multi
curve cable belt conveyor of
1800 tph capacity.
HOME
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d
ALUMINA REFINERY
One among top ten in worl
15.75 ltpa of calcined alumina
Atmospheric digestion at low
temperatureBayers process
Distributed
controldigital process
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T
HOME
CAPTIVE POWER PLAN
960 MW Capacity (8x120MW)
Microprocessor-controlled burner
management, Computerised
DAS, automated turbine run-up,brush less excitation of
generators, islanding facility.
7th 8th DCS in and units.
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-IALUMINIUM SMELTER
180 KA cell technology ofAluminium Pechiney France
Hall-Herauolt electrolysis process.
Integrated
3.45ltpa of
3 pot-lines
Aluminium plant
Aluminium. with
240electrolytic pot shell each.
I
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CAST HOUSE
Cast house
Strip casting plant
CARBON AREA
Green anode plant
Bake oven furnaceRodding shop Rolled
unitproducts
ALUMINIUM
SMELTER
POT LINES
Pot regulation system
Fume treatment plant
Alumina handling
system
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POT LINES
FumetreatmentplantPotregulationsystem
Alumina handling ystem
HOMELaddle and pipecleaningshop
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SYSTEM
ROOM
Anodes
connected
in
parallel(1
6)
POT REGULATIONElectrolytic pot cell connected in
-A
series
1050180
KA
V
Cathode is
carbon bar
+Aluminiu
m metal
ROOM-
BHOME
-
+
A001A120
B001 B120
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POT REGULATION SYSTEMSERVER 2
MAN-MACHINE
INTERFACESERVER 1
DIGITAL MULTI-
SWITCHING
DEVICE
Communicator 1 Communicator 2
1 2 3 14 15 16 1 2 3 14 15 16
Group of 15
Electronic pot
micro
controller HOME
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FUME TREATMENTAlumina from
SILO
PLANT
Fluorine gas from
Electrolytic pot
Dry scrubbing infilter reactors CLEAN
GAS
Fluorinated Alumina
to Electrolytic pot
shell HOME
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ALUMINA HANDLING SYSTEM
Transfer of alumina through
Bottom air fluidisation
Storage of alumina in PrimarySILO (6 no. each
Supply to
FTPs as quantity.
of 13,500 t)
per required
HOME
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RedundantRACKS
SYSTEM CONFIGURATION Man -ProcessInterface
PC-PLC
Communication
I/O
processors
HOME
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PROGRAMMABLE
LOGICCONTROLLER
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Early control systems consisted of huge control boards consisting ofhundreds to thousands of electromechanical relays.
An engineer would design the system logic, electricians would receivea schematic outline of logic then implement the logic with relays.
The schematic was commonly called LadderSchematic
The ladder displayed all switches, sensors, motors, valves, relays etc inthe system.
Problems: Long commissioning time, dependency on mechanicalreliance, Any system logic design change required the power to thecontrol board to be isolated stopping production.
History
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General Motors was among the first to recognize a need to replacethe systems wiredcontrol board
Hydramatic Division of GM specified the design criteria for theprogrammable controller in 1968.
Goal Eliminate the high cost associated with inflexible, relay
controlled systems.
History
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New Controller Specifications:
Solid State System Computer Flexibility
Operate in Industrial Environment (vibrations, heat, dust etc.)
Capability of being reprogrammed
Easily programmed and maintained by electricians and
technicians.
History
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In 1969 Gould Modicon developed the first PLC.
Strength Programmed with Ladder Logic
Initially called Programmable Controllers PCs
Now - PLCs,Programmable Logic Controllers PLCs have evolved from simple on/off control to being able to
communicate with other control systems, provide productionreports, schedule production, diagnose machine and processfaults.
History
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Advantage of PLC Over Relay Style
RELAY PLC
1-Hard wiring 1-Less wiring
2-Changes difficult 2-Easy modification
3-More power 3-Low power
4-More maintenance 4-Less maintenance
5-Difficult to expand 5-Ease of expansion
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Control Systems Types
Programmable Logic Controllers
Distributed Control System
PC- Based Controls
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Programmable Logic Controllers
Sequential logic solver
PID Calculations.
Advanced Subroutines
BIT Operations.
Data Transfer.
Text Handling.
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Applications : Machine controls, Packaging, Palletizing, Material handling, similar
Sequential task as well as Process control
Advantages of PLC :
They are fast and designed for the rugged industrial environment. They are attractive on Cost-Per-Point Basis.
These Devices are less Proprietary ( E.g.. Using Open Bus Interface.)
These Systems are upgraded to add more Intelligence and Capabilitieswith dedicated PID and Ethernet Modules.
Disadvantages of PLC : PLC were Designed for Relay Logic Ladder and have Difficulty with
some Smart Devices.
To maximize PLC performance and Flexibility, a number of OptionalModules must be added
PLC holds only one copy of program
Programmable Logic Controllers
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PLC Types Nano (Small)
Micro (Medium)
Large
Basic criteria for PLC Types
Memory Capacity I/O Range
Packaging and Cost per Point
Programmable Logic Controllers
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Sizing of PLC
Micro PLCs: I/O up to 32 points
Small PLC: I/O up to 128 points
Medium PLC: I/O up to 1024 pointsLarge PLC: I/O up to 4096 points
Very Large: I/O 4096 Onwards
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Most Basic of PLC Systems
In the most basic of PLC systems, a self contained (shoe box) PLC has 2terminal blocks, one for Inputs and one for Outputs
Today, most PLCs in this category are know as Micros. Typically theyprovide front panel LED status indication of I/O and Processor states
InputsOutputs
C
R
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Modular Chassis Based PLCs
The vast majority of PLCs installed today are modular chassis basedsystems consisting of:
1. Processor Module (CPU)
2. Input & Output Modules
3. Chassis
4. Power Supply
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Modular Chassis-less PLC Systems
Also available from many vendors are Chassis less but still ModularPLC systems. These systems still require a Processor, I/O Modules, andPower Supply, but in place of a chassis these components mountdirectly onto a panel, din rail, and many use a tongue and grove system
to allow easy insertion and removal
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Central Processing Unit (CPU)
Input Output Modules
Power Supply Bus system
Programming Device
P L C Components
CPU
PROGRAM
DEVICE
IN OUT m
MODULEMODULE
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Basic PLC Schematic
CPU
Power Supply
Memory Input Blocks
Output Blocks
Communications
Expansion Connections
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It is a micro-controller based circuitary. The CPU consists of
following blocks :
Arithmatic Logic Unit (ALU), Timing / Control ckt, Programmemory, Process image memory (Internal memory of CPU)
Internal timers and counters and Flags, Address stack andinstruction registers
The Central Processing Unit (CPU) Module is the brain of thePLC.
P L C : Central Processing Unit
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CPU Module
CPU performs the task necessary to fulfill the PLC functions. These
tasks include Scanning, I/O bus traffic control, Program execution,
Peripheral and External device communication, special functions ordata handling execution and self diagnostics.
Self
Check
Execute
Code
Scan
Inputs
Update
Outputs
PLC Program
SCAN
Primary role to read inputs, execute the control program, update
outputs.
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Memory
The memory includes pre-programmed ROM memory containing
the PLCs operating system, driver programs and application
programs and the RAM memory.
PLC manufacturer offer various types of retentive memory to save
user-programs and data while power is removed, so that the PLC
can resume execution of the user-written control program as soon as
power is restored.
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Memory
Many PLCs also offer removable memory modules, which are plugged
into the CPU module.
Memory can be classified into two basic categories: volatile and non-
volatile.Volatile memoryloses state (the stored information) when power
is removed.
Nonvolatile memory, maintains the information in memory even
if the power is interrupted.
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Memory
Some types of memory used in a PLC include:
ROM (Read-Only Memory)
RAM (Random Access Memory)
PROM (Programmable Read-Only Memory) EPROM (Erasable Programmable Read-Only Memory)
EEPROM (Electronically Erasable Programmable Read-Only
Memory)
FLASH Memory Compact Flash Can store complete program information, read &
write text files
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I/O Modules
Input and output (I/O) modules connect the PLC to sensors and
actuators.
Provide isolation for the low-voltage, low-current signals that the PLCuses internally from the higher-power electrical circuits required bymost sensors and actuators.
Wide range of I/O modules available including: digital (logical) I/Omodules and Analog (continuous) I/O modules.
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These modules act as link between field input sensors and the CPU.
Analog input module : Typical input to these modules is 4-20 mA,0-10 V, Ohms, mV
Ex : Pressure, Flow, Level Tx, RTD (Ohm), Thermocouple (mV)
Digital input module : Typical input to these modules is 24 V DC,115 V AC, 230 V AC
Ex. : Switches, Pushbuttons, Relays, pump valve on off status
PLC : Input module
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PLC : Input module
Transfer of data:-I/P sensor to CPU
Conversion:- 24vdc/230vac to 5vdc
Isolation :- By Opto Coupler
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Input Devices
Pushbuttons
Selector Switches
Limit Switches
Level Switches
Photoelectric Sensors
Proximity Sensors
Motor Starter Contacts
Relay Contacts
Thumbwheel Switches
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SOURCING vs. SINKING DC Inputs
DC
Power
Supply
Field
Device
DC
Input
Module
+
- DC COM
IN1
C
DC
Input
ModuleField
Device
DC
Power
Supply
+
-
+VDC
IN1
IN1
VDC
SINK SOURCE
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Analogue Inputs/Outputs
Analogue input cards convert continuous signals via a A/D
converter into discrete values for the PLC
Analogue output cards convert digital values in then PLC to
continuous signals via a D/A converter.
Resolution can be important in choosing an applicable card
Example, for a temperature input of 0 to 100 degrees C
For 8 bit resolution the value in the PLC is 0 to 255
For 12 bit resolution the value in the PLC is 0 to 4095 For 12.5 bit resolution the value in the PLC is 0 to 6000
For 13 bit resolution the value in the PLC is 0 to 8192
For 16 bit resolution the value in the PLC is 0 to 32768
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Analogue Cards
Typical Analogue Input
signals are:
Flow sensors
Humidity sensors
Load Cells
Potentiometers
Pressure sensors
Temperature sensors
Vibration
Analogue Output signalscontrol:
Analogue Valves
Actuators
Chart Recorders Variable Speed Drives
Analogue Meters
Typical Analogue Signal Levels
4-20mA
1-5 Vdc
0-10 Vdc
-10 10Vdc
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PLC : Input module
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These modules act as link between the CPU and the output devices
in the field.
Analog output module : Typical output from these modules is 4-20mA, 0-10 V
Ex : Control Valve, Speed, Vibration
Digital output module : Typical output from these modules is 24 VDC, 115 V AC, 230 V AC
Ex. : Solenoid Valves, lamps, Actuators, dampers, Pump valve on offcontrol
PLC : Output module
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Relay type -For AC or DC
Transistor Type Logic(TTL) -For DC
Triac (Triode AC) type - For AC
Isolated common type -For different device
PLC : Output module - Types
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PLC : Output module
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Output Devices
Valves
Motor Starters
Solenoids
Control Relays
Alarms
Lights
Fans
Horns
Relays
120 VAC/VDC
240 VAC
24 VAC/VDC
Triac
120/230 VAC
Transistor MOSFET
24 VDC
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Relays
The most important consideration when selecting relays, or relayoutputs on a PLC, is the rated current and voltage.
For transistor outputs or higher density output cards relay terminalblocks are available.
Advantage of individual standard replaceable relays
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I/O Specifications
INPUT VOLTAGE Magnitude and type of voltage ON-STATE INPUT VOLTAGE RANGE voltage at which signal is
recognized
Nominal current per input Min. current to operate input circuit
AMBIENT TEMP RATING Max temp of surrounding the I/O
module INPUT DELAY Time duration for input signal to be on before
known as valid input. ( 9-ms to 25ms)
NOMINAL OUTPUT VOLTAGE It is min and max o/p operatingvoltage.e.g. Rated 120 v ac o/p ckt. Works in 92 to 138 v range.
MAX O/P CURRENT RATING Max current a single o/p ormodule can safely carry under load
OFF STATELEAK CURRENT PER O/P Max value of leak currentflows through the o/p in OFF position
ELECTRICAL ISOLATION Max volts between I/o and logic ckt.
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The power supply gives the voltage required for electronics module(I/O Logic signals, CPU, memory unit and peripheral devices) ofthe PLC from the line supply.
The power supply provides isolation necessary to protect the solidstate devices from most high voltage line spikes.
As I/O is expanded, some PLC may require additional powersupplies in order to maintain proper power levels.
P L C : Power Supply
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It is path for the transmission of the signal . Bus system is
responsible for the signal exchange between processor and I/Omodules
The bus system comprise of several single line ie wires / tracks
Types of Bus
P L C : Bus System
Address bus - Location
Data bus - Carries DataControl bus - Synchronization
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Special Modules
RF ID
Voice
Gas Flow Calculation
Weigh Cell
Hydraulic Servo
ASCII
Fuzzy Logic
Temperature Sensor
Temperature Control
Heat/Cool Control
Field Bus Cards
DeviceNet, Profibus etc
Lonworks, BACNet
Fast Response (Interrupt)
PID
Loop Controller
BASIC Cards
RS232 Comms Modbus ASCII/RTU
Ethernet Comms
High Speed Counters
Position Control Cards
Peer to Peer Comms Controller Link
DH+
Modbus Plus
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Input Scan
Program ScanOutput Scan
Housekeeping
START
Each ladder rung is scanned usingthe data in the Input file. Theresulting status (Logic beingsolved) is written to the Outputfile (OutputImage).
The status of external inputs(terminal block voltage) is written tothe Input image (Inputfile).
The Output Image data istransferred to the externaloutput circuits, turning the
output devices ON or OFF.
Internal checks onmemory, speed andoperation. Service anycommunication requests,etc.
PLC Operating Cycle
This scan cycle can be interrupted if required using interrupts
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PLC Architecture Evolution
Mid - 1970s : Discrete Machine Control
Programming
Terminal
PLC
I/O
Programming Language :
- Relay ladder logic- Flexibility in altering
Control system operation
Connection is Point to Point
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Early - to - Mid 1980 : Discrete and Process Control
PLC Architecture Evolution
Reasonable Computer
Running PLC
Programming Software
PLC
I/O
Programming Language :
- Ladder Program
- PID
- Data Storage
MS - DOS
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PLC Architecture Evolution
Late 1980s to early 1990s : Discrete and ProcessControl
PC runningPLC Programming Software
PLC
I/O
Connection in networked allowing
Multiple PLC
PLC became a part of the
developing enterprise resource
system
Windows
PLC
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Today: Distributed I/O Modules
Distributed I/O modules
PLC
Distributed I/O scanner
Data Communication Bus
PLC Architecture Evolution
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Remote
I/O Network
SPLITTERS
FIBER OPTIC LINK
TAPS
Today : Hot Redundant System
PLC Architecture Evolution
Level of redundancyPower Supply
CPU
I/OCommunication
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Controller Controller
Controller
Controller
Workstation Workstation Workstation Workstation
Switched Hub
PLC Architecture EvolutionToday : Ethernet Technology in PLCs
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Remote
Platform
Wireless Modem / GSM Communication
Wireless Modem / GSM Communication
PLC
H M I
Display
PC
PLC Architecture Evolution
Today : Wireless communication
PLC
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8 Analog Inputs 1Analog Output
Up/Down FastCounter
Up Counter
Programming Terminal PC Connection
Unitelway Port for connectionof up to 5 Slaves
PCMCIA memory expansion port
PCMCIA communications port
TSX37-22
Built in display for I/O(in-rack, AS-i) and Diag
I/O Modules
Configuration of PLC : Modicon
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Configuration of PLC : Siemens
CPU
External Power
Supply
I/O Modules
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Configuration of PLC : Allen Bradley
CPU
Power SupplyI/O Modules
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Configuration of PLC : GE FANUC
CPU
I/O Modules Back plane
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PLC Programming Standards
The open, manufacturer-independent programmingstandard for automation is IEC 61131-3. You can thus choosewhat configuration interface you wish to use when writing yourapplication :
Ladder Diagram
Statement List
Instruction List
Function Block Diagram
Sequential Function Chart
Structured Text
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PLC : Communication Protocol
It is a set of rules for data transmission when PLC is connected tonetwork
RS-232 (Recommended standard)
RS-485
MPI(Multi point Interface)
Profibus
DH(Data Highway)
Ethernet Controlnet
Devicenet
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Baud rate (Communication Speed)
It is rate of data transmission on network Unit is bits/second
Range:-120 bits /sec
to
100 Mega bits per second
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Selecting a PLC
Number of logical inputs and outputs
Memory
Number of special I/O modules
Expansion Capabilities
Scan Time
Communication
Software
Support
Cost
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Manufactures Major Brands
OMRON
Allen Bradley
Schneider
GE Fanuc Siemens
Automation Direct (Koyo)
Toshiba
Mitsubishi
Hitachi
Keyence
VIPA
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PLC Standardization
IEC 61131 Based on IEC 1131 (1992) standard, developed to be a
common and open framework for PLC architecture. IEC 61131-1 Overview IEC 61131-2 Requirements & Test Procedures IEC 61131-3 Data Types & Programming IEC 61131-4 User Guidelines IEC 61131-5 Communications IEC 61131-7 Fuzzy Control
IEC 61131-7 Guidelines for the application and implementationof programming languages
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PLC Programming
The purpose of a PLC Program is to control the state of PLCoutputs based on the current condition of PLC Inputs
Different PLCs support different languages, but the mostpopular PLC language is know as Ladder Logic.
PLC Ladder Logic purposely resembles Relay Logic
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| | |/|
Read / ConditionalInstructions Write / ControlInstructions
| | |/|
| | |/|
| |
| | |/| ( )
| |
( )
( )
( )
( )
| |
Start (Rung #1)
End (Rung #5)
Ladder Logic Concepts
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Read / Conditional
Instructions
Write / Control
Instructions
No Logical Continuity
|/| | |
True False False
|/| |/|
( )
( )
True True True
Logical Continuity
Ladder Logic Concepts
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IF input 4AND input 5have power
THEN energize output 0
| |I/4
| |I/5
( )O/0
Logical Continuity
T T T
On
Logical AND Construction
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IF input 4OR input 5have powerTHEN energize output 0
| |I/4
| |I/5
( )O/0
Logical Continuity
F
T
On
| |I/4
| |I/5
( )O/0
Logical Continuity
T
F
On
Logical OR Construction
T i l C i
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|/|I/11
| |I/5
|/|I/7
|/|I/1
| |I/3
| |I/2
| |I/4
|/|I/0
| |I/1
| |I/1
|/|I/8
| |I/9
( )O/0
| |I/10
Typical Construction
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L1 L2
PB1 LS1 PS2 SOL6
DEVICE
PB1
LS1
PS2
SOL6
| | ( )| | | |I/5 I/6 O/0I/7
HHP
I/5
I/6
I/7
O/0
Logix
I:0/5
I:0/6
I:0/7
O:0/0
ADDRESS
Addressing Examples
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INPUT Address Assignment:
PB1- I/4 PB2- I/5LS1- I/6 LS2- I/7
LS3- I/8 LS4- I/9
OUTPUT Address Assignment:
SOL2- O/0 M1- O/1
|/|
CR3
CR3 M1
PB1 LS1 SOL2
PB2LS1
LS3
LS4
I/8
I/4 I/6 O/0
O/1
| | | | ( )
I/5I/7 B/0
| | | | ( )
| |
|/|B/0
( )
Relay Logic to Ladder Logic
| |I/9
l bl
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Available Instructions
Sequence Input
Output
Control
Logic
Timer and Counters Comparison
Range Comparison
Data Movement
Data Shift
Step / Step Next
Serial Communications
Text String Processing
File Manipulation
Increment/Decrement
Conversion
ASCII
Number Systems
Math
Floating Point Math
Statistics
Scaling
PID
PID with Auto tune
Clock / Date Block Processing
IF,THEN,ELSE,LOOP
Table Processing
LIFO, FIFO
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Few more Instructions
SEQUENCERS
SHIFT REGISTERS
DATA HANDLING
HIGH SPEED COUNTER
SUBROUTINES
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Programmable Logic ControllersSiemens
Si PLC
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Types of SIEMENS PLC:-
Compact:- I/O number fixed
Modular :- I/O can be as per selection
Siemens PLC
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SIMATIC S7-300 within the System Family
Mid- and low-endperformance range
S7-300
Micro PLCs
S7-200
+ Programming devices+ STEP 7 software
+ Communication
+ Human-machine Interface
High-end range /medium range
S7-400
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Highlights - Diverse applications
ET 200S, ET200X
Intelligent Interface modules,based on S7-300 or the standardS7-300 as PROFIBUS DP Slave
Distributed Safety -S7-300F with fail safe I/O modulesfor central and distributedapplications
C7 control systems
with integrated HMI on the basisof the S7-300
The C7 Systems are used where close integration with field, control and operation is required. For ex. Formulation andpackaging in Pharma industry. These are costly systems and are used only for some high end applications.
These are the remote I/O modules . Some of them have CPU inbuilt in them. The se I./Os are connected on Profibusnetwork.
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Siemens S7 Ranges
200 300 400
Series 212 to 226 312 to 318 412 to 418
Digital I/O 256 1024 16384
Analog I / O 38 256 4000
ProgrammingS/W Micro win Simatic Manager
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PS -Power Supply
CPU -Central Processing UnitIM -Interface ModuleSM -Signal Module(I/O modules)Bus Connector Rack (rail) Eleven slot railCP -Communication Processor
FM -Functional Module
Siemens S7 PLC Hardware
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The cost-effective entry into TIA The sophisticated solution for medium-range I/O configurations
CP The standard CPU for a wide range of applications with integratedPROFIBUS DP Interface
The new high-end CPU in S7-300
The high-performance CPU with system features of the S7-400
Siemens S7 300 CPU Overview
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The new standard CPUs
Instr. / DataUser memory
DI / DO
AI / AO
ProcessingtimeBit instructionWordinst. +/- IFloatingp.+/-R
Flags
Counters
Timers
Connections
Interfaces
315-2 DP
128 KB
1024
256
0,1 s1 s3 s
16384
256
25616
PROFIBUS-DP Master/Slave
CPU 317-2 DP
512 KB
1024
256
0,05 s0,2 s1,0 s
32768
512
51232
PROFIBUS-DP(Master/Slave)MPI also. DP
CPU 318-2 DP
84 K / 256 KB512 KB
1024
256
0,1 s0,1 s0,6 s
8192
512
51232
PROFIBUS-DP(Master/Slave)MPI also DP
CPU 314
48 KB
1024
256
0,1 s1 s3s
2048
256
25612
CPU 312
16 KB
256
64
0,2 s2 s6 s
1024
128
1286
Th C t CPU Hi hli ht
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The Compact CPUs - Highlights
Integrated functions
Count/measure, control, positioning
Integrated I/O
Digital, Analog
Integrated communication interfaces
In addition to MPI, also PROFIBUS DP and point-to-point
CPU 312CCPU 313CCPU 313C-2 PtPCPU 313C-2 DP
CPU 314C-2 PtPCPU 314C-2 DP
T t d di ti f ti
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Test and diagnostics functions
System diagnostics Fault diagnostics from CPU to I/O
internal CPU services (e.g. error message with time stamp)
Process diagnostics ( Seperate PDIAG software is required) Monitoring critical process signals at the program level
Simply assign parameters using S7-PDIAG and ProAgent
CPU generates messages automatically for S7 HMISo that your service personnel can diagnose the problem sooner
C C i i
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CPU Communication ports
MPI Profibus
Baud ratemax
1.5 Mb PS Default
187.5 KbPS12 Mb PS
No. of max.
nodes 32 126
NetworkLength
4000 Ftwithoutrepeater
4000 Ftwithoutrepeater
MPI is used for PLC programming, inter CPU communication, SCADA/HMI communication
In addition to above Profibus is also used for remote I/Os and Drives communication .Now a days Profibus is implemented on industrial Ethernet as Profinet.Profibus can also be implemented using fibre optic technology.
M d l f S7 300
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Modules for S7-300
Power Suppliesclassified according to capacity
Signal modules
for digital and analog signals and hazardousareas
Point-to-Point CPsfor I/O devices of all kinds
Function modulesfor high-speed counting, positioning, closed-loop control and cam control
Si S7 300 Di i l d l
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Siemens S7 300 - Digital modules
Voltage/current range
Channels(optically isolated)
Sensors
Resolution
Encoding time
Ex (i)
Diagnostics
Digital outputs
DC 24 / 48...125 VAC 5...230 V0,5 / 1 / 2 / 5 A
8, 16, 32electr./ Relay
Namur / Ex(i)
yes
Digital inputs
DC 24...125 VAC 120 / 230 V
8, 16, 32
Switches,2-wire Beros
Namur / Ex (i)
yes
Si S7 300 A l d l
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Voltage/current range
Channels(optically isolated)
Sensors
Resolution
Encoding time
Ex (i)
Diagnostics
Analog outputs
+/- 10 V, 0...10 V,+/- 20 mA,0/4...20mA, u.a.
2, 4, 8
12 - 16 bit incl.sign bit
0.8 ms
Namur / Ex(i)
yes
Analog inputs
+/- 80mV...10 V,+/-3,2mA,0/4...20mA u.a.
2, 4, 8with integratedlinearization
2-,3-,4-wire resistor(Pt100),thermocouples
9 to 16 bit incl.sign bit
2.5 ... 100 ms
Namur / Ex (i)
yes
Siemens S7 300 - Analog modules
Point to point CPs for special interfaces
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Point-to-point CPs - for special interfaces
1 or 2 interfaces, up to 76 kbit/s Different physical transmission
environment Standard or custom-specific
protocols
Programmingdevice, PC,computers
Robotcontrols
Opto-electronics
Printer
SIMATIC S5 and also PLCsfrom other manufacturers
Scanner,barcode reader,identificationsystems
Weighing systems,controllers
Siemens S7 300 Function Modules (FM)
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Siemens S7 300 - Function Modules (FM)
The FM are used when ... tasks have to be taken care of
at top speed ... The very highest accuracy and
reproducibility are required
... Special sensors or actuatorsare required
... technologicaltasks requirepracticalsolutions
Counting, measuring,cam control, positioning,closed-loop control
Siemens S 7 300 Design
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Siemens S 7 300 Design
Rugged, enclosedmodules
Integrated, easy-to-connectbackplane bus
High module density,
up to 32 channels per module Minimum mounting depthdue to recessed
and covered connectors and plugs
Power supply modules in the case ofAC mains connection for supplying theS7-300 and sensors/actuators
Siemens S7 300 Mounting
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Siemens S7 300 - Mounting
Simply snap the module onto the mounting rail
No slot rules
No jumper settings requiredon the module
Horizontal or vertical mounting
Front connectors with in
Screw- or
Spring-loaded terminals
Self-codingfront connectros
make sure that the rightconnector is plugged in aftermodule replacement
CPU M i ti
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CPU memory divided in blocks:-
OB -Organization Block(OB1-main block)FC -Functions(Subroutine user defined)FB Functional Block(defining function with memory)DB -Data Block(creating memory data)
SFC -System Functions (syst. Block)SFB -System Function block(syst. Block)
CPU Memory organisation
CPU Memory organisation
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Load memory:- User program stored, capacity can be
changed by MMC up to 256k
Work memory:-Instructions required program execution
System memory:-Holds OS, Timer, Counter, memory bits,
Process Image Memory, buffer diagnostics.
CPU Memory organisation
Siemens Addressing Concepts
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All the addresses are based on byte numbers.The Singnal Modules (I/O) can be put from slot no 4 onwards. When we do the I/Oconfiguration byte numbers required for each module are defined by the system which wecan use in the programming.
In certain CPUs these Byte numbers can be changed by the user. Generally system definedaddressing is preferred as it avoids memory holes.
Siemens Addressing Concepts
The typical addressing in Siemens S7 300 compact PLCs is as follows
Digital Input starts with I 124.0 (Byte No 124) ,
Digital Output starts with Q 124.0 (Byte No 124)
Analog Input starts with PIW 256 or PIW 752
Analog Output starts with PQW 256 or PQW 752
Similar I/O mapping is followed for Profibus Dp based remote I/Os
Siemens I/O Addressing
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I 0 . 0 (0 to 7)I 1 . 0 (0 to 7)Q 0 . 0 (0 to 7)Q 1 . 0 (0 to 7)
Four Bytes are allotted for each slot
32 I/O are permitted in each slot
One rail 8 slot are for SM,DP&FM
32 .8 =256 I/O in one rail
Four rail configuration permitted
256 . 4 = 1024 I/O permitted in four rails
Compact Module address is 124 to 127
INPUTorOUTPUT
BYTE
ADDRESS
BIT
ADDRESS
Siemens I/O Addressing
Siemens Memory addressing
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M-Marker memory
MB-memory byteMW-memory wordMD-memory double word
If total memory bits 1024 then 1024/8=128Memory byte no. - 0 to 127Bit Level Address:-M0.0M0.7M1.0M1.7..M127.7Byte Level Address:-MB0,MB1,MB2,MB3,MB1278 BITS=255 OR -128 TO 127
Siemens Memory addressing
Siemens follows overlapping memory areas so user should be careful in usingthis addresses
Siemens Memory addressing
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WORD Level Address:-MW0,MW2,MW4,..MW126
16 BITS = 65535 OR -32768 to 32767Word address is used to display Timer & counter value and for
Integer function within above limitDOUBLE WORD Level Address:-MD0,MD4,MD8,MD12432 BITS = -2147483648 to 2147483647
Double Word address is used for Integer function value morethan word limit
Siemens Memory addressing
Siemens Memory addressing
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TIMER :-T0 T 511(depends on module)COUNTER :- C0 C 255 FC :- FC1.. FC 511 FB :- FB1. FB 511 DB :- DB1. DB 511
Siemens Memory addressing
Siemens Programming Language
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I0.0 I0.1 Q0.0Ladder :- ------||-----||-----------( )----
STL :- Structural Text LanguageA(A I0.0A I0.1)
= Q0.0
Siemens Programming Language
Siemens Programming Language
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FBD:- Functional Block Diagram
I0.0 Q0.0I0.1 & =
Siemens Programming Language
Siemens Syntaxes in programming
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I(Integer) - MW(word address)W(Word) - ,,
D (Double) - MD (double word address)DI (Double Integer) - ,,DW (Double Word) - ,,
R (Real) - ,,
Siemens Syntaxes in programming
Siemens Types of MPI adapters
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PLCMPI ADAPTER
PCRS485 RS232
PLCUSB ADAPTER PCRS485 USB
Universal Serial Bus
Siemens Types of MPI adapters
Siemens Organisational Blocks
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OB1 Main cuclic execution block. All other blocks must be called from here.
OB10 - 17 Time-of-day interrupts Execution to be done on specific time can be called here.
OB20 - 23 Time-Delay interrupts Keep repeating after delay time.
OB10 &35 Cyclic interrupts Keep repeating aftre defined time interval
OB40 - 47 Hardware interrupts Certain hardware moduels are capable of generatinginterrupts for ex. High speed counter. These blocks are executed when the hardware interrupts aretriggered.
Siemens Organisational Blocks
These are interface between user program and operating system.
Siemens Organisational Blocks
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OB60 Multicomputing interrupt Used when multi cpu systems are usedOB100 Warm restart - Memory retained but program starts from begining
OB 101 Cold Restart Initialise memory and start from begining
OB121, 122 Error interrupts When error happens it triggers these interrupts
Siemens Organisational Blocks
Siemens S7 300 Central Configuration
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im361
IM361
IM361
IM360
Cable upto 10 meter
Siemens S7 300 Central Configuration
With the 312 and 312C CPUsonly a single structure ispossible on one rack
No restrictions to the selectionof modules
Central rack + max.3 expansionracks possible- 32 modules
Siemens Instructions
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----||----- NO----|\|---- NC----( )---- O/P COIL
----( S )---- SET COIL----( R )---- RESET COIL----( P)---- POSITIVE EDGE----( N )---- NEGATIVE EDGE
Siemens Instructions
Siemens LED Description
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SF 1. Hardware faults 2. Programming errors
3. Parameter assignment errors 4 Calculation errors
5. Faulty memory card 6. I/O fault/error
7. Communication error
BATF The backup battery is missing, faulty or not charged. It also is onwhen an accumulator is connected. The reason for this is that the user programis not back up by the accumulator.
STOP Flashes When CPU is not processing a user program.The CPU requests a memory reset
Siemens LED Description
Siemens LED Description
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5 V DC This must be ON. It shows CPU Logic power (5 V) available.
FRCE If any I/O force exist in CPU it will glow Yellow.
Run Solid green represents CPU in Run Mode
STOP Solid Yellow CPU in stop mode
Siemens LED Description
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Programmable Logic ControllersAllen Bradley
PLC Ranges Available
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PICOMicroLogix
Compact LogixSLCPLC Obsolete (Control Logix is used)Flex Logix Discontinued
Control Logix
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Allen Bradley PLC
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PLC S/W I/O capacity
Pico Pico soft 32
Mirco Logix RS logix500 156SLC 500 RSlogix500 4096/4096
Logix platform RSlogix5000 1,28,000
Communication s/w:-
RS linx :- With variety of software drivers
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AB PLC Hardware
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Central Processing UnitInput ModuleOutput Module
Power supplyBus SystemRack (chassis)
Chassis types:-
4,7,10&13 Slots
(17 slots in Logix Platform)
AB PLC Hardware
AB PLC CPU Memory Organisation
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CPU memory divided in two parts:-Data Files
Program Files
Data files:-
System 0 -Manufacturer programSystem 1 -Reserve file
Ladder 2 -Main user file-ladder 3 to 255 for
subroutine program
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AB PLC CPU Memory Organisation
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Program files:-
0 -Output - O -- o/p status1 -Input - I -- i/p status2 -Status - S2 -- CPU data
3 -Binary - B3 -- Flag(memory bit)4 -Timer - T4 -- Timer status5 -Counter - C5 -- Counter status
6 -Control - R6 -- Specific data7 -Integer - N7 -- whole no. data8 -Float - F8 -- Decimal no.data
9 to 255 used to create new Program Files
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AB PLC Addressing I/O
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: . /
I : 1 . 0 / 0 (0 to 15)
I : 1 . 1 / 0 ,,O : 2 . 0 / 0 ,,O : 2 . 0 / 0 ,,
FILE
LETTERSLOT
NO
WORD
NO
BIT
NO
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Addressing BINARY (Flag)
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: /B3 : 0 / 0 (0 to 15)
B3 : 1 / 0 ,,. . .. . .. . .
B3 : 15 / 15
FileLetter
FileNumber
WordNumber
BITNumber
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Addressing of Programming Instructions
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TIMER :- T4:0 . T4:255(as per PLC)
COUNTER :- C5:0. C5:255CONTROL :- R6:0. R6:255INTEGER :- N7:0 N7:255
FLOAT :- F8:0. F8:255
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Addressing of Symbols
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----||----- XIC NO
----|\|---- XIO NC----( )---- OTE O/P COIL
----( L )---- OTL O/P COIL----( U )---- OTU O/P COIL
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Communication Protocols Comparison
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DH+ DH485 DeviceNet
ControlNet
Baud ratemax
230.4kbits/s
19.2kbit/s
500kbit/s
5 Mbit/s
No. ofmax.
nodes
64 32 64 99 1
NetworkLength
3.048 km 1.2 km 0.487 km 30 km 15 m
Communications protocols are broadly distinguished by speed of the communication,number of nodes supported and length of network.
p
AB_DF1
19.2 kbp/s
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Allen Bradley : SLC system
System Components
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y p
A modular-hardware SLC / 1746 control system at minimum consists of aprocessor module and I/O modules in a single 1746 chassis with a powersupply. The 1746 power supply connects to the left end of each 1746 chassis.You can configure a system with one, two, or three local chassis, for a total of30 local I/O or communication modules maximum. You connect multiple
local chassis together with chassis interconnect cables to extend thebackplane signal lines from one chassis to another.
Choose the processor module with the on-board communication ports youneed. You optionally add modules to provide additional communicationports for the processor. For I/O in locations remote from the processor, you
must add an I/O scanner module for ControlNet, DeviceNet, or UniversalRemote I/O port.
Product Design : CPU
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The 1746/1747 platform provides a modular-hardware system formaximum flexibility. SLC 500 processors are single-slot modules that youplace into the left-most slot of a 1746 I/O chassis. For 1746 I/O in alocation remote from the processor, the I/O adapter is a single-slot
module that you place into the left-most slot of a 1746 I/O chassis.
The 1746 I/O chassis are built for back-panel mounting and are available.
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SLC 500 processors are available with4096 Input and 4096 OutputUser memory 1K instructions with 64K wordsLocal and Distributed I/O using I/O scanner module with Control / Devicenet or remote linkBuilt in 1 or 2 communication ports
Provision for expansion of memory
Product Design : CPU
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You can configure a system with one, two, or three local chassis, for atotal of 30 local I/O or communication modules maximum. You connectmultiple local chassis together with chassis interconnect cables to extendthe backplane signal lines from one chassis to another.
For many modules, because you wire to a removable terminal block thatunplugs from the module, you do not need to disconnect wiring toreplace an I/O module.
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Product Design : CPU
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SLC 500 processors are available in a large range of forcible I/O (4096inputs plus 4096 outputs maximum) and maximum user memory (1Kinstructions through 64K words). Several modular processors are capableof controlling remotely located I/O. By adding an I/O scanner module,you can use these processors to monitor/control these remotely located
I/O across ControlNet, DeviceNet, and Universal Remote I/O links.
The 1746/1747 platform provides a modular-hardware system formaximum flexibility. SLC 500 processors are single-slot modules that youplace into the left-most slot of a 1746 I/O chassis. For 1746 I/O in alocation remote from the processor, the I/O adapter is a single-slotmodule that you place into the left-most slot of a 1746 I/O chassis.
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Product Design : Chassis and I/O
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The 1746 I/O chassis are built for back-panel mounting. The 1746 I/Ochassis is available in sizes of 4, 7, 10, or 13 module slots. The 1746 I/Omodules are available in densities of a maximum of 32 I/O per module.
You can configure a system with one, two, or three local chassis, for atotal of 30 local I/O or communication modules maximum. You connectmultiple local chassis together with chassis interconnect cables to extendthe backplane signal lines from one chassis to another. This same 30-I/O-module limit applies to a chassis remote from the processor with an I/Oadapter module in the first slot.
gmodules
Communication
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Various models of SLC processors have various on-board ports forcommunication with other processors or computers. Also, separatemodules are available to provide additional communication ports forcommunication with other processors, computers, and remotely located
I/O.
Each SLC processor has one or two built-in ports for either EtherNet/IP,DH+, DH-485, or RS-232 (DF1, ASCII, OR DH-485 protocol)communication.
I/O adapter modules for 1746 I/O are also available for ControlNet andUniversal Remote I/O links.
Communication Protocols
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Comparison
DH+ DH485 DeviceNet
ControlNet
Baud ratemax
230.4kbits/s
19.2 kbit/s 500 kbit/s 5 Mbit/s
No. of max.nodes
64 32 64 99
NetworkLength
3.048 km 1.2 km 0.487 km 30 km
Communications protocols are broadly distinguished by speed of the communication, number of nodes
supported and length of network.
PLC Programming Software
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