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<== Date ==> <== Thread ==>

Subject: Spurious "Channel write request failed" messages
From: Michael Ritzert <michael.ritzert@ziti.uni-heidelberg.de>
To: tech-talk@aps.anl.gov
Date: Sat, 23 Sep 2017 10:47:20 +0100
Hi all,

since upgrading from 3.14 to 3.16.1, I see the following messages on the console of an IOC:
DB CA Link Exception: channel "dest1"
DB CA Link Exception:  native  T=DBR_DOUBLE, request T=DBR_DOUBLE, native N=1, request N=1,  access rights {RW}
DB CA Link Exception: "Channel write request failed", context "dest1"

This is from a dfanout record that simply pushes a value to another IOC.

However, the write succeeds.

It's totally reproducible with these two DBs run in softIOCs:

sender.db:
record(calc, "count") {
        field(SCAN, "1 second")
        field(VAL, "0")
        field(PINI, "YES")
        field(INPA, "count")
        field(CALC, "A+1")
}

record(dfanout, "send1") {
        field(DOL,  "count CPP")
        field(OMSL, "closed_loop")
        field(OUTA, "dest1")
}

record(dfanout, "send2") {
        field(OMSL, "supervisory")
        field(OUTA, "dest2")
}

receiver.db:
record(ao, "dest1") {
}

record(ao, "dest2") {
}

There's one messages every second about dest1, and one on every write to send2.

Cheers,
Michael
-- 
Dr. Michael Ritzert                     Tel: +49 621 181 2883
Schaltungstechnik und Simulation        Fax: +49 621 181 2734
Technische Informatik, Uni Heidelberg   michael.ritzert@ziti.uni-heidelberg.de
68131 Mannheim, Germany                 http://sus.ziti.uni-heidelberg.de

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Replies:
Re: Spurious "Channel write request failed" messages Ralph Lange

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