Experimental Physics and
Industrial Control System

Richard Farnsworth <[email protected]> · Thu, 17 Dec 2009 11:33:30 +1100

Nick,
At the Australian synchrotron, we use Ethernet as a field bus also. Ethernet is not deterministic in theory , but with clever networking you can get around most of the issues in practice. We separate the accelerator networks from the beamlines (and other places). We use gateways if we need data transfer.

Our primary PLC's use Modicon premium PLCs (Schneider) and a Modbus/IP driver (Not Mark Rivers one though, although it may have a common ancestor). Also our PILZ safety system PLC's, and a number of other systems use Modbus. We do have some other Ethernet drivers for a few variant PLC's (Siemens and Rockwell and our building systems).

One problem we are getting into is that the keep alive chatter (Broadcast) on the PLC's is starting to impact network performance and we may look at separate networks (And second network cards) on certain PLC's in the future.

Our IOC's talk via Moxa's terminal servers to serial devices, RS232 primarily, but also RS422 and RS485. We also have a number of Cosylab supplied PC/104 soft IOC's with RS485 daughter cards.

Almost no VME, most analog and digital I/O is performed using PCI I/O cards on a mixture of Soft IOC's and some running Redhawk real time Linux. We will be removing them in the near future and just using standard Linux.

Temperature measurements are done in part using a tiny (cheap) Modbus device called an "ITM". More details if you need that. We recently replaced most of them as they (ironically) got too hot wher we mounted them and they failed.

VME (as a power supply/crate) is only in use on the timing system and one or two special devices. We use Linux IOC's and a Struck VME to PCI bridge for the odd VME only case.

I'd like to say no VxWorks, but I've discovered recently that the Modicon premiums actually use VxWorks internally.

A strong emphasis on Linux throughout, the major exceptions being our PLC development tools and the Dipole power supply uses (Ahhchoo, Spit, Ting) Windows CE. Even our GUI's use wine on Linux to run the windows executables we develop with Borland Delphi (We will change to QT over time).

Richard Farnsworth | Head of Computing | Australian Synchrotron
p: (03) 8540 4118 | f: (03) 8540 4200 | m: 0421 082 147
[email protected] | www.synchrotron.org.au
800 Blackburn Road, Clayton, Victoria 3168

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System