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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | Re: IOC warning when connecting to 64 devices |
| From: | Mark Rivers via Tech-talk <tech-talk at aps.anl.gov> |
| To: | "tech-talk at aps.anl.gov" <Tech-talk at aps.anl.gov>, Abdalla Ahmad <Abdalla.Ahmad at sesame.org.jo> |
| Date: | Tue, 6 May 2025 12:44:22 +0000 |
|
Hi Abdalla,
That is a fairly common problem when a lot of records are set to SCAN=I/O Intr and all process at iocInit.
The example startup script for areaDetector IOCs has this line at the end to prevent the ring buffer overflow:
callbackSetQueueSize(5000)
Mark
From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>
Sent: Tuesday, May 6, 2025 2:47 AM To: tech-talk at aps.anl.gov <Tech-talk at aps.anl.gov> Subject: IOC warning when connecting to 64 devices Hi
We developed an asyn port driver for a group of power supplies, 64 in total, controlled via Ethernet. When the IOC was developed to connect to all power supplies at once, I got the following warning:
callbackRequest: cbLow ring buffer full
The IOC became slow and could not handle processing some PVs at .1 second scan. I ended up splitting the main IOC into 4 IOCs each controlling 16 devices and the system is working fine. I would like to know more what causes this warning and is it possible to have 1 IOC controlling all 64 devices?
Best Regards, Abdalla Al-Dalleh Control Engineer SESAME
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