Re: Fast stream-device IOC suddenly disconnects

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

Hello Mark

I wanted to wait for it to disconnect again to investigate further, unfortunately still the ioc shell shows no error messages and the terminal statistics just stops counting. I know disconnectOnReadTimeout will solve it but I really want to troubleshoot further and see if something can be done on the device's firmware side because we changed the terminal server two times with the same scenario. 

Best Regards 

Abdalla

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From: Mark Rivers <rivers@cars.uchicago.edu>
Sent: Friday, October 3, 2025 5:18:24 PM
To: Abdalla Ahmad <Abdalla.Ahmad@sesame.org.jo>
Cc: tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
Subject: Re: Fast stream-device IOC suddenly disconnects

Hi Abdalla,

I’ve made 3 suggestions:

- Set disconnectOnReadTimeout

- Log all communication to see if it stops

- Look at the statistics in the terminal server

Have you tried these?

Mark

Sent from my iPhone

On Sep 28, 2025, at 10:08 AM, Abdalla Ahmad <Abdalla.Ahmad@sesame.org.jo> wrote:



Hi Mark

Thanks for the info. I forgot to mention that the device is a serial port connected to a terminal server, and the device has been tested locally streaming data for periods longer than what we have so I don't think it just stopped sending data.

Best Regards 

Abdalla.

TEST
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From: Mark Rivers <rivers@cars.uchicago.edu>
Sent: Sunday, September 28, 2025 5:02:36 PM
To: tech-talk@aps.anl.gov <Tech-talk@aps.anl.gov>; Abdalla Ahmad <Abdalla.Ahmad@sesame.org.jo>
Subject: Re: Fast stream-device IOC suddenly disconnects

 

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