Experimental Physics and
Industrial Control System

Elliott Wolin <[email protected]> · Tue, 09 Feb 2010 17:36:01 -0500

Hi,
Some clarifications:
I have no control over the "other" system, and cannot modify it in any
way. The system supplies cryogens to the my setup. I'm told that flow
rates, temperatures, etc. are all available as EPICS PV's. They have no
PLC's that I know of.
I only have an A-B PLC and a Windows PC that runs the PLC programming
software. I can run programs on the PC (or on a Linux box, if needed).
I want the PLC to be able to access the flow rates, temperatures, etc.
that they provide as PV's.
Hi,
For a small and short-lived test setup my A-B ControlLogix PLC needs
to read some EPICS values from another system. What are my options?

How about using an Ethernet/IP server library? I.e. write a program
that uses EZCA to poll the EPICS values periodically, then serve them
to the PLC via Ethernet/IP...does this work?
I prefer not to have to purchase anything (e.g KEPserver software),
and just want to use freeware to get past this test.
Any suggestions?

				Sincerely,
					Elliott

================================================================================

Those raised in a morally relative or neutral environment will hold

no truths to be self-evident.

Elliott Wolin
Staff Physicist, Jefferson Lab
12000 Jefferson Ave
Suite 8 MS 12A1
Newport News, VA 23606
757-269-7365
================================================================================

Mark Rivers wrote:

Are you already communicating with this PLC from an EPICS IOC? If so, are you writing to the PLC or only reading from it?

If you are writing to it, then why not have that IOC get the EPICS values and write them to the PLC in addition to the data it is already writing?

Mark

________________________________
From: [email protected] on behalf of Elliott Wolin
Sent: Tue 2/9/2010 4:15 PM
To: [email protected]
Subject: Accessing EPICS PV from Allen-Bradley PLC

Hi,
For a small and short-lived test setup my A-B ControlLogix PLC needs to
read some EPICS values from another system.  What are my options?
How about using an Ethernet/IP server library?  I.e. write a program
that uses EZCA to poll the EPICS values periodically, then serve them to
the PLC via Ethernet/IP...does this work?
I prefer not to have to purchase anything (e.g KEPserver software), and
just want to use freeware to get past this test.
Any suggestions?
Thanks,
--
                                Sincerely,
                                        Elliott

================================================================================

 Those raised in a morally relative or neutral environment will hold

no truths to be self-evident.

Elliott Wolin
Staff Physicist, Jefferson Lab
12000 Jefferson Ave
Suite 8 MS 12A1
Newport News, VA 23606
757-269-7365
================================================================================

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System