Experimental Physics and
Industrial Control System

"Pawel Kowalski - BiRa Systems Inc." <[email protected]> · Thu, 12 Mar 2009 13:41:40 -0600

Thank you Paul. I will verify that our process variables can support
waveforms, at this time I do not know if our test application does. I will
need to do a bit more research on ASG before I can comment. 

The process variable names you will be able to customize fairly easily in
the software. As I said we do plan to make this open source and the epics db
records can be configured using FTP or you can load the database using an
NFS share. We will do some thinking on how we can make it easy to have our
program then use those names, using a simple configuration file comes to
mind. I think this also addresses Ralph Lange's question about this issue.

On the topic of LabVIEW/EPICS communication NI was nice enough to recently
release a epics client for newer versions of LabVIEW (I think it only works
with 8.6) without having to buy a DSC license. If anyone is interested that
can be downloaded here:

http://zone.ni.com/devzone/cda/tut/p/id/7987

I have tested this and it has a strange bug where it times out the first
time it reads or writes to a process variable but after that initial miss it
seems to work fine.

Sincerely,
Pawel Kowalski
BiRa Systems Inc.
505-881-8887
http://www.bira.com

-----Original Message-----
From: Paul Sichta [mailto:[email protected]] 
Sent: Tuesday, March 10, 2009 10:15 AM
To: Pawel Kowalski - BiRa Systems Inc.
Cc: [email protected]
Subject: Re: Looking for feedback on what epics users require

Pawel,
Would the power supply/IOC process variables be only scalar values, or will
there be waveforms as well.  How fast can the waveforms/scalars be
updated/monitored/served.  Regarding the configuration of the records
served, how can the user customize the names and other attributes, such as
Access Security (ASG) and units?

Regarding the client,
the Channel Access protocol is the interface for any client. That means you
should provide a specification of the served record names and their
characteristics, at least one good enough so that users can write their own
clients.  If you provide a LabVIEW-based client, that is readily useable but
will it be an executable?  Otherwise the user needs to purchase LabVIEW.
Also, NI supports the Channel Access protocol in their DSC (data supervisory
and control) LabVIEW add-on.  But, that's also expensive.

-ps

Pawel Kowalski - BiRa Systems Inc. wrote:
> Hello,
>  
> My company is researching providing an epics IOC with some of our 
> power supplies. I would like to get some feedback from the epics 
> community on what exactly would be required. First let me start off by 
> saying that epics is still a new area for me so hopefully these 
> questions aren't dumb, we are still in the early research stages on this.
>  
> What we would like to do is provide a system with each device that 
> will host an EPICS IOC. This will be a vxWorks based system running epics
base 3.14.
> This system will communicate with our device using ethernet and 
> convert standard UDP commands that our devices work on to process 
> variables. So for example our clients would now have a process 
> variable they could use to monitor or set the voltage of a power supply
(IE: powersys:voltage).
>  
> For the client side we would like to develop a LabVIEW interface, we 
> would most likely not be developing a custom C/C++ application for the
client.
>  
> Would this be adequate for most epics users or would more be required 
> to integrate this into an existing epics network? Would people use the 
> LabVIEW client we develop or do most labs use their own custom 
> software to control/monitor epics enabled equipment? Any feedback from 
> the community would be greatly appreciated, thank you.
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System