35
Ethernet Based Technology for
Distributed Test Systems
Joshua Hernstrom
PXI & VXI Product Support Engineer
13 Aug 2003 - Room 15
Agenda
• Evolution of distributed test systems
• Common hardware architectures for distributed test
• Software technologies for distributed test
• Conclusion
What is Distributed Testing?
• Networking in general allows for sharing of data
• We define distributed testing to allow for easy remote
execution, control and presentation.
Acquire Analyze Present
“Big Iron” ATE Traditional GPIB
Based ATE
time
User Defined
ATE
Instrument on
a Card - VXI
Evolution of Distributed Test Platforms
No distribution GPIB network VXIbus network Ethernet, PXI,
Fieldpoint
Distributed Test Systems
Remote Monitoring
& Control Network
Analysis
Presentation Network
Agenda
• Evolution of distributed test systems
• Common hardware architectures for distributed test
• Software technologies for distributed test
• Conclusion
Networking Hardware Architectures
• Past technologies have converged on three prevalent
standards
– Ethernet (10 Base-T or -FL), 10 Mbps
– Fast Ethernet (100 Base-T or -FX), 100 Mbps
– Gigabit Ethernet (1000 Base-T or -FX), 1000 Mbps
Wireless Hardware Architectures
• 802.11
– Wireless ethernet, aka “WiFi”
– Rapid growth of “hot spots”
– Established in 1997 with currently three variations
• 802.11a achieves 54 Mbps at approx. 60 ft.
• 802.11b achieves throughput up to 11Mbps at approx. 300 ft.
• 802.11g increases that to 54 Mbps at approx. 300 ft.
NI Hardware Networking Products
• FieldPoint / Compact FieldPoint
– FP and cFP-2000 families
– FP-1601 Ethernet module
• PXI
– PXI embedded controllers
– PXI-8231 (gigabit) module
• VXI
• NI GPIB-ENET/100
• ENET Serial Family
Network
Network
Network Network
Network Network
Agenda
• Evolution of distributed test systems
• Common hardware architectures for distributed test
• Software technologies for distributed test
• Conclusion
Modular Architecture for Distributed Test
GUI
Application
Driver
Device I/O
Co
nfi
gu
rati
on
Measurement &
Automation Explorer
LabVIEW, LabWindows/CVI, etc.
NI-DAQ, NI-VISA, NI-488, etc.
PXI, FieldPoint, GPIB, etc.
Windows, Linux, Mac OS, etc.
Network Software Technologies
• LabVIEW Remote Front Panels
• DataSocket
• NI-VISA Networking
• LabVIEW VI Server
• WinXP Remote Desktop
• LabVIEW RT
LabVIEW Remote Front Panels
When you need to make measurements remotely or when many users need to have access to the same equipment
• Tool to control with a LabVIEW front panel from a Web browser or from another LabVIEW environment
• Requires no programming
• Many clients can view the same panel
• Control can be passed between clients
Driver
Device I/O
GUI
Network
Application
Remote Front Panels - Use Cases
• Universities
– Enable distance learning
– Enhance classroom lectures
– Share research equipment
• Remote Control Labs
– Isolate testing
• Monitoring
– Easily observe remote tests
Remote Front Panels - Demo
DataSocket
• Supports buffered transfers
• Simultaneous multiple clients
• Multiple ADEs supported
• One high-level API for all data source types
• DataSocket Server manages networking
When you need to easily pass data between applications or pass data over the Internet
Driver
Device I/O
Co
nfi
gu
rati
on
GUI
Application
GUI
Application Network
NI-VISA Networking When you need to programmatically access PXI, GPIB, VXI,
etc. resources on a remote machine using existing instrument drivers or code.
• VISA : Virtual Instrument Software Architecture – Industry Standard
– Supports multiple hardware interface types • PXI, GPIB, VXI, USB, Serial and more
– Most instrument drivers use VISA for I/O
Remote
NI-VISA
LAN Instrument
Support
Raw Sockets
Support
NI-VISA Networking – Remote VISA
• Access resources on a remote workstation.
• Use existing applications written with NI-VISA
Network
Device I/O
Co
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rati
on
GUI
Driver
Application
Network
Co
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rati
on
NI-VISA Networking
• LAN Instrument Support
– Easily access stand-alone TCP/IP enabled
instruments (aka VXI-11)
– Full 488.2 functionality
• Raw Sockets Support
– Create TCP/IP support for stand-alone instruments
– Equivalent to TCP libraries in LabVIEW & CVI
Driver Co
nfi
gu
rati
on
GUI
Application
Device I/O
Network
Network
LabVIEW VI Server
When you need to programmatically control a LabVIEW application from another computer or LabVIEW VI.
• Call a LabVIEW VI remotely
• Control a LabVIEW application from another
program
• Programmatically edit properties of a VI and
LabVIEW
• Retrieve LabVIEW and platform information
GUI
Application
Network
Driver
Co
nfi
gu
rati
on
Device I/O
Application
Driver
Co
nfi
gu
rati
on
Device I/O
Application
LabVIEW VI Server - Use Cases
• Communication with LabVIEW RT programs
• Remote Control of LabVIEW programs
• Programmatic User Interface Control
• Cross platform support (Windows, Linux)
Network
LabVIEW VI Server - Demo
Network Software Technologies
• LabVIEW Remote Front Panels
• DataSocket
• NI-VISA Networking
• LabVIEW VI Server
• WinXP Remote Desktop
• LabVIEW RT
XP Remote Desktop
• When you want configuration and set
up flexibility for your test system
– Laptop/PC control of headless test
system
– Allows complete control of PXI test
system over the network
– Windows XP on the server (PXI test
system)
– Streams data to remote PXI controller
Driver
Device I/O
GUI
Application
Network
Co
nfi
gu
rati
on
XP Remote Desktop - Demo
Network Software Technologies
• LabVIEW Remote Front Panels
• DataSocket
• NI-VISA Networking
• LabVIEW VI Server
• WinXP Remote Desktop
• LabVIEW Real-Time
LabVIEW Real-Time
When you need an operating system
that offers:
• Stand alone or embedded operation over the network
• Deterministic response
• Increased reliability
GUI
Driver
Device I/O
RT Application
Network
Co
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rati
on
Application
LabVIEW Real-Time - Comparison
Operating
System
Determinism Deployment
Real-Time OS
• Scheduling system
• High-priority tasks
execute first
• Direct control over all tasks
running on the system
• Headless operation for easy
distributed deployment
General-purpose
OS
High-priority tasks can be
preempted by lower-
priority tasks
Frequently requires user
intervention by design
LabVIEW Real-Time System - Overview
Develop on Host Computer
Execute on RT Target
Network
Network
PXI
FieldPoint
Compact FieldPoint
LabVIEW Real-Time - Use Cases
Type Example
Event Response Remote temperature control and
monitoring. Can provide safe shutdown
in an emergency
Control Distributed temperature monitoring,
compare to desired temperature, initiate
appropriate heating
or cooling
Data Acquisition Remote monitor temperature
LabVIEW Real-Time - Demo
Communication
Loop Normal Priority
DISK
Control
Loop Time-Critical
RT Target
External
Application
DISK
Host Computer
NI Network Software Comparison
Technology Networked
Interface Strength Drawback
Remote Front
Panels
GUI • No programming req’d
• Browser interface
• Less flexible in
application
DataSocket Data • Many APIs, Datatypes Supported
• Buffered transfers
• Lower speed data
transfers
Remote NI-VISA Driver,
Device I/O
• No programming req’d
• VISA is industry standard
•Only VISA devices
• Certain transfers slow
LabVIEW VI Server GUI, Data,
Applications
• Very flexible programmatic
control
• More involved
programming
XP Remote
Desktop
GUI,
Configuration
• Complete control of remote OS
• Allows device configuration
• Only WinXP
targets allowed
LabVIEW RT Data,
Application
• Deterministic
• Headless deployment
• More involved
programming
Virtual Instrumentation
Remote Front
Panels
DataSocket
LAN Instruments Remote VISA XP Remote Desktop
Driver
Device I/O
GUI
Network
Application
Driver
Device I/O
Co
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rati
on
GUI
Application
GUI
Application Network
Device I/O
Co
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rati
on
GUI
Driver
Application
Network
Co
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gu
rati
on
Driver Co
nfi
gu
rati
on
GUI
Application
Device I/O
Network
VI Server
GUI
Application
Network
Driver
Co
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gu
rati
on
Device I/O
Application
Driver
Co
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gu
rati
on
Device I/O
Application
Driver
Device I/O
GUI
Application
Network
Co
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gu
rati
on
GUI
Driver
Device I/O
RT Application
Network
Co
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gu
rati
on
Application
LabVIEW RT
Conclusion
• NI utilizes many of the latest technologies to provide the
customer with many options when it comes to distributed
test systems.
• As technology improves, networks act as an intermediate
bus allowing for high performance, distributed, cross-
platform test systems.
