Re: Fast stream-device IOC suddenly disconnects

[Mark Rivers via Tech-talk <tech-talk@aps.anl.gov>]

Hi Abdalla,

It looks like the device streams data without needing to send a command, i.e. it is not a write/read operation, correct?

If it freezes then that suggests that the device has stopped sending data for some reason.  That should mean that the asyn read operation timed out, and StreamDevice should be reporting that?

You can try adding this to the startup script after drvAsynIPPortConfigure:

asynSetOption($(PORT), 0, "disconnectOnReadTimeout", "Y")

That will disconnect the port when a read times out, which is equivalent to writing 0 to the CNCT field.

Mark

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From: Tech-talk <tech-talk-bounces@aps.anl.gov> on behalf of Abdalla Ahmad via Tech-talk <tech-talk@aps.anl.gov>
Sent: Sunday, September 28, 2025 6:08 AM
To: tech-talk@aps.anl.gov <Tech-talk@aps.anl.gov>
Subject: Fast stream-device IOC suddenly disconnects

 

Hi

 

We have a device streaming data at 200 Hz controlled with stream device, parses the streamed data and writes to corresponding PVs. The problem is that every day or two, the readings freeze. At first I had to restart the IOC but I noticed that the IOC does not show any error so I re-connect the asyn port through writing 0 to the CNCT field and it worked. The st.cmd file has the port configured:

 

drvAsynIPPortConfigure(“PORT”, “ip-address:port-number”, 0, 0, 0)

 

What could be the issue here? I am using EPICS base 7.0.9 and latest version of all modules.

 

Best Regards,

Abdalla Al-Dalleh

Control Engineer

SESAME