Experimental Physics and
Industrial Control System

Ralph Lange <[email protected]> · Wed, 11 Mar 2009 10:03:11 +0100

Hello Pawel,

To connect to your power supplies through UDP on standard ethernet, you

do not need to run the IOC on VxWorks. So-called "soft IOCs" run as a

multi-threaded process on any "host side" OS, such as Linux (preferred)

or Windows. If the only device connection of the IOC is through

IP/ethernet, this solution is probably more flexible and efficient (many

soft IOCs can run on a single machine), and a lot less expensive

(inexpensive hardware, free OS). You could go as far as only supplying

the software needed to create and run the power supply IOC on a machine

the customer would provide.

If your systems are to be integrated into an existing EPICS based

structure, most installations will have their own solution for display

(panel) managers, alarm handlers, achivers etc., based on the variety of

tools that are part of the EPICS toolkit. Creating some user interfaces

that you ship with your IOCs is a good thing to do, but forcing your

customers to use stuff that you supply would probably rather cause

resistance, and (in the best case) your beautiful panels would just be

not used.

Be aware that the Channel Access network protocol that people will use

to integrate your IOCs is completely relying on channel names to

describe hierarchies and - to some degree - properties. Any existing

EPICS system will have a strict naming convention for channels, and any

"foreign" IOCs with channels that don't follow that customer convention

will cause a lot of grief and trouble when being integrated. You should

try to create a solution that allows channel names to be adapted to

customer naming schemes. This is not easy.

(IE in our case your "powersys:voltage" name would of course be

completely unacceptable and be replaced by something like

"Q3PD5R:rdVolt" - first part: device name, second part: channel name,

both following strict conventions.)

Thanks for asking, (I mean it - please continue to ask!)
Ralph

On 10.03.2009 15:45 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