Experimental Physics and
Industrial Control System

"keith.thorne" <[email protected]> · Tue, 12 Sep 2017 13:34:13 -0500

Dear Mark

The cainfo looks fine, with “Native data type: DBF_STRING” and “Request type: DBR_STRING”.  command-line caget comes backs with a string.

Of course, the MEDM text monitor says Format “decimal’.  I tried to use the MEDM editor to save it as “string" but see no change in the underlying *.adl file.  
But according to the MEDM manual, it will always think it is a number, even for ‘string’.

These strings are typically longer than a numeric field (up to 40 characters), so I guess it puts out 00.00 as ‘exponential’ notation when there are too many characters?

So, what is the way to display string fields for a PV in MEDM? 

Thanks
	Keith

> On Sep 12, 2017, at 12:21 PM, Mark Rivers <[email protected]> wrote:
> 
> Hi Keith,
> 
> Some questions:
> 
> - What does command line cainfo say about that PV?
> - What does command line caget show for that PV?
> - In your medm display what "Format" have you selected for the text update widget, e.g. "decimal", "string", etc.?
> 
> Mark
> 
> 
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of keith.thorne
> Sent: Tuesday, September 12, 2017 11:52 AM
> To: EPICS mailing list
> Subject: MEDM display of string records not updating from PCASpy/PyEpics
> 
> Dear all
> 
> 	We have an odd behavior here with a continuously-running MEDM display.
> 
> In most cases, where the EPICS IOC is running in C or similar, the MEDM displays of string variables happily update when the underlying PV is updated.
> 
> However, we have a simple EPICS database that is done with PCASpy. We then use a pyEpics client to regularly update records in the EPICS database using pvPut().
> 
> The updated numeric records all work fine.  However, the string records (when updated) appear as 00.00 or similar in the MEDM display.
> If we open a new MEDM display, the correct value is shown.  If we slightly resize the MEDM display, it also updates.
> 
> Any idea what is going on?
> Is there something in the PCASpy database record fields we need to set to make this work?
> 
> - Using command-line caput() we get updated values.
> 
> — I was going to try an MEDM->caQtDM conversion to see if we get any different behavior.
> 
> Thanks
> 	Keith Thorne
> 
> ------
> Keith Thorne <[email protected]>
> CDS Software Engineer
> LIGO Livingston Laboratory
> Livingston, LA 70754
> Phone: (225)686-3168 Fax: (225)686-7189
> 

------
Keith Thorne <[email protected]>
CDS Software Engineer
LIGO Livingston Laboratory
Livingston, LA 70754
Phone: (225)686-3168 Fax: (225)686-7189

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System