Experimental Physics and
Industrial Control System

"David Dudley" <[email protected]> · Tue, 05 Sep 2006 14:58:29 -0500

Most of what I'm looking to update / replace are Siemens 505 PLC systems.  I'm told I can create an executable program in 'C' or another language, that I can download into the device, but I don't have any documentation on that capability yet.  Unfortunately, these things use a specialized Ethernet card that isn't directly addressable.  I'm hoping to convert these things into a IOC directly, either using another Ethernet card, or using a PPP connection through one of the serial ports.  The chassis holds VME sized cards, and uses the standard VME P1 connector bus, but I don't believe i'm going to be as lucky as being able to just put a VME processor card into them (I wish!).

I spent 3 or 4 days looking for I/O cards for VME or compactPCI, and have discovered that there are very few industrial I/O cards offered.  Industrial cards are usually optically isolated, and directly handle 110VAC on inputs and outputs, and the analogs all handle 4-10ma current loops without converters.  You can use a simple resistor for converting an input (technically considered a 'kludge' by most in industrial working circles), but analog outputs generally take special adapters to convert from voltage to current.

You can't normally run voltage I/O for hundreds of feet without interference from other signals in an industrial plant, but you usually can with current loops.

David Dudley

>>> "Dalesio, Leo `Bob`" <[email protected]> 09/05/06 2:15 PM >>>
You don't need to use VME though - you could just as well talk to PLCs from your Linux or Windows box. What kind of I/O do you have sitting around? We do a lot of RS232, GPIB, OPC, and many PLC manufacturers. Unfortunately, the web page is woefully underdeveloped for the IO that is supported.
Bob 

-----Original Message-----
From: Steven Hartman [mailto:[email protected]] 
Sent: Tuesday, September 05, 2006 11:51 AM
To: David Dudley
Cc: [email protected] 
Subject: Re: Equipment Availability

On Tue, 5 Sep 2006, David Dudley wrote:

> who makes the chassis and backplane?

There are a large number of manufacturers, covering a large price range.
Take a look at VITA or the ads in VMEbus Systems magazine. Here are two I am familiar with:

	http://tracewellsystems.com/ 
	http://www.wiener-d.com/ 

--
Steve Hartman
[email protected] || 919-660-2650
Duke Free Electron Laser Laboratory

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System