Experimental Physics and
Industrial Control System

Florian Feldbauer <[email protected]> · Mon, 25 May 2015 15:51:48 +0200

Hey Mark,

I'm using the asynPortDriver for all my device support implementations
so far and I really like it!
But I'm not sure if (and how) I could effectively use the asynPortDriver
for the device support for iseg.

To access a certain value I need the address of the crate (multiple
crates can be connected to the CAN bus), the address of the module (up
to 20 modules per crate) and the address of the channel (up to 48
channels per module).
The parameters for the server look like this:
"<crate-address>.<module-address>.<channel-address>.<paramtername>"
E.g. if I want to read a the current voltage of channel 47 in module 4
of crate 0, the parameter is called:
"0.4.47.VoltageMeasure"

If I want to access a module or crate related parameter the unused
address values are omitted in the command.

Do you have an idea how to implement this addressing scheme using only
_one_ asynPortDriver?
The hole device support should to be easy to configure...

Cheers,
Florian

On 05/15/2015 12:50 PM, Mark Rivers wrote:
> 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
> 
> 
> --
> ----------------------------------------
> | Dr. Florian Feldbauer                |
> |                                      |
> | Helmholtz-Institut Mainz /           |
> | Johannes Gutenberg-Universität Mainz |
> | Johann-Joachim-Becher-Weg 36         |
> | D-55128 Mainz                        |
> |                                      |
> | Office: SB1 / 00-213                 |
> | Phone:  (+49)6131 / 39-29605         |
> ----------------------------------------
> 
> 

-- 
----------------------------------------
| Dr. Florian Feldbauer                |
|                                      |
| Helmholtz-Institut Mainz /           |
| Johannes Gutenberg-Universität Mainz |
| Johann-Joachim-Becher-Weg 36         |
| D-55128 Mainz                        |
|                                      |
| Office: SB1 / 00-321                 |
| Phone:  (+49)6131 / 39-29605         |
----------------------------------------

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System