RE: Make waveform from ai record

[Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>]

Hello Ziga

 

Thanks, this is working as I expected by setting the waveform scan to 1 second. This maybe a general question not related only to my case, but how to conditionally trigger a PV from within EPICS records? I just had an idea where I want to export or scan the waveform once I had 200 samples exactly, already in the IOC I am tracking the number of samples.

 

Best Regards,

Abdalla Al-Dalleh

Control Engineer

SESAME

P.O. Box 7, Allan 19252, Jordan
Tel: +96253511348 , ext. 265

Fax: +96253511423

Email : abdalla.ahmad at sesame.org.jo
Website: www.sesame.org.jo

 

From: Žiga Oven <ziga.oven at cosylab.com>
Sent: Thursday, February 20, 2025 10:37 AM
To: Abdalla Ahmad <Abdalla.Ahmad at sesame.org.jo>; tech-talk at aps.anl.gov
Subject: RE: Make waveform from ai record

 

Hi Abdalla,

 

One way how to create waveform from scalars with EPICS records is Compress Record with an ALG field set to Circular Buffer and INP field pointing to your AI record.
https://epics.anl.gov/base/R7-0/8-docs/compressRecord.html

You still have to configure processing of the compress record (either FLNK from AI record, or CP flag on the INP link) to capture all the 200 samples.

 

Then you can point a waveform record to read the 200 sample with either 1 second SCAN rate or you can create some other (“complex”) logic to extract the data into waveform only when 200 “fresh” samples are in the compress record.

 

Hope this helps,

 

Žiga

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Abdalla Ahmad via Tech-talk
Sent: Thursday, February 20, 2025 07:56
To: tech-talk at aps.anl.gov
Subject: Make waveform from ai record

 

Hi

 

I have a fast ai record (200 Hz) in a stream-device-based IOC. Is there a "standard way" within EPICS records to transform these 200 samples into a single waveform record of size 200 processed at 1 second for example? Thanks.

 

Best Regards,

 

Abdalla.

Control Engineer

SESAME