Re: Accessing EPICS PV from Allen-Bradley PLC

[Elliott Wolin <wolin@jlab.org>]

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: tech-talk-bounces@aps.anl.gov on behalf of Elliott Wolin
> Sent: Tue 2/9/2010 4:15 PM
> To: tech-talk@aps.anl.gov
> 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
>
> ================================================================================
>
>
>
>
>