Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Mon, 21 May 2012 08:54:33 -0400

What do you get from a command-line camonitor?

I think the issue is this:
The Channel Access network protocol doesn't know about record types, NELM,
NORD, waveform record, ...

All we see is a channel with an array of strings.

On the IOC, the NORD may change, but that doesn't affect the size of the
Channel Access array that's transferred.
The CSS BOY text update widget still gets the full NELM array and it shows
the string value by displaying each element, comma-separated.

See also http://www.aps.anl.gov/epics/tech-talk/2010/msg00720.php :
"Channel access clients receive the size information when they connect.
There is no support in Channel Access for dynamic array sizes."

With CSS BOY you could use a script to hack around this:
Read the actual PV, create a string with only the non-empty array elements
and display that as the text update's value.
But it might be better to work around this further down on the IOC:
Create just one string with the text that you want.
Since a stringin/stringout record is limited to 40 chars, use a waveform
of CHAR for that custom text.

Thanks,
Kay

From:  Pavel Masloff <[email protected]>
To:  "[email protected]" <[email protected]>
Subject:  [CSS] commas in TextUpdate

Why I see commas in the TextUpdate widget displaying a waveform when
NELM>NORD??
For example, I have a waveform of strings. NELM=10, NORD=3. As a result:

text1, text2, text3,,,,,,,

-- 
Best regards,

Pavel Maslov, MS
Controls Engineer at Pulsed power Lab
Efremov Institute for Electro-Physical Apparatus
St. Petersburg, Russia

Mobile: +7 (951) 672 22 19
Landline: +7 (812) 461 01 01

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System