Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Fri, 15 May 2015 10:50:41 +0000

Hi Florian,

Both of the things you asked about are implemented in the standard asyn device support.  Updating output records on a callback from the driver was added in asyn R4-26:

http://www.aps.anl.gov/epics/modules/soft/asyn/R4-26/RELEASE_NOTES.html

Support for setting timestamps was added in asyn R4-22:

http://www.aps.anl.gov/epics/modules/soft/asyn/R4-22/RELEASE_NOTES.html

So you might consider writing an asyn port driver to talk to your OPC, rather than device support.  It may be simpler.

Mark

________________________________________
From: [email protected] [[email protected]] on behalf of Florian Feldbauer [[email protected]]
Sent: Friday, May 15, 2015 1:51 AM
To: EPICS Tech Talk
Subject: Question about device support

Hey all,

I'm currently working together with the company iseg Spezialelektronik GmbH
to develop EPICS device support for their high voltage power supplies.

Two questions came up so far:
1) It is possible that some Control values change their values,
    e.g. if a trip occures the "channel is on" control word is set to off.
    Can the device support in such a case change the value of a bo record?
    Will the record be processed when changing its value from device
support?
    (I was thinking of some kind of callback here)

2) The device support will not directly communicate with the hardware,
    but with a daemon in between (iseg also wants to support OPC server
and others,
    so one common interface for all).
    This daemon gives me the value and timestamp of its last change.
    Is it possible to give this timestamp through the device support to
the record?
    From the record reference manual I guess not...
    What would be your suggestion to make the timestamp
available/visible to the operator/experts?

Best regards,
Florian

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| Dr. Florian Feldbauer                |
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| Helmholtz-Institut Mainz /           |
| Johannes Gutenberg-Universität Mainz |
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System