RE: multiple asynRecord communication conflict

[Mark Rivers <rivers@cars.uchicago.edu>]

There should be no possibility of such a conflict.  asynManager keeps a lock on the drvAsynSerialPort driver so that only one thread can talk to it at a time.

 

What TMOD are you using with your asyn records, Write/Read, Write, etc.?  If you need to do both a write and then a read you should use Write/Read, because that is atomic, no other thread can do a write before the read is performed.

 

Have you tried turning on asynTrace for the drvAsynSerialPort port?  You can then see what is happening.

 

Have you run asynReport on the drvAsynSerialPort port when it is no longer responding?

 

Are the asyn records actually still processing when the serial port is no longer communicating?

 

I have many IOCs with multiple asyn records talking to the same serial port and have never seen a problem.

 

Is this on Linux or Windows?

 

Mark

 

 

From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf Of Zohar, Sioan
Sent: Wednesday, March 25, 2015 10:22 AM
To: tech-talk@aps.anl.gov
Subject: multiple asynRecord communication conflict

 

Hi,

 

I have several asynRecord instances running in a softIOC talking to a single serial port and I suspect they are conflicting.

 

Everything runs fine for several hours, and then the asynRecord writes stop reaching the serial port.  (I confirmed this by sniffing the serial output using the serial port from another computer).

 

This error is not observed when there is only one instance of the asynRecord.

 

This problem does not occur on every computer, so perhaps it depends on environment settings?

 

I've tried daisy chaining the asynRecords by flnk'ing them.  Two asynRecords are set to scan = passive, and the other is set to scan = 1 second. I thought this would prevent the possibility of multiple asynrecord instances from talking to the port at once, but the problem persists.

 

Thanks in advance for your help.

 

Sioan