Re: dbpf error - Operation not permitted at IOC initialization

[Eric Norum via Tech-talk <tech-talk at aps.anl.gov>]

Others with more experience with EPICS database development may have better approaches to this, but for my applications I have:

1 - A periodically-scanned record that reads a value from the attached device:

record(bi, "$(P)$(R)sysmonTrig_") {

    field(DESC, "Trigger system monitor readback")

    field(DTYP, "asynInt32")

    field(INP,  "@asyn($(PORT), 0x0000, 0)")

    field(ZNAM, "Running")

    field(ONAM, "Rebooted")

    field(SCAN, "5 second")

    field(PINI, "YES")

    field(FLNK, "$(P)$(R)reconnChk_")

}

2 - A calcout record that monitors the status of the periodically-scanned record and invokes an event record when the scanned record goes from bad to good:

#

# Push values to FPGA on reconnection.

# Monitor the status of a periodically-scanned readback to detect (re)connection.

#

record(calcout, "$(P)$(R)reconnChk_") {

    field(DESC, "Push on reconnect")

    field(INPA, "$(P)$(R)sysmonTrig_.STAT NPP")

    field(INPD, “1")

    field(CALC, "A=0&&D!=0;D:=A")

    field(OOPT, "When Non-zero")

    field(OUT,  "$(P)$(R)reconnX_.PROC")

}

record(event, "$(P)$(R)reconnX_") {

    field(DTYP, "Soft Channel")

    field(VAL,  “RECON")

}

3 - A bunch of fanout records triggered by the above event record — these fanouts trigger the output records to push their values to the device:

record(fanout, "$(P)$(R)BD:rc_") {

    field(DESC, "Push beam dump values on (re)connect")

    field(SCAN, "Event")

    field(EVNT, "RECON")

    field(LNK1, "$(P)$(R)xxxxxxxx")

    field(LNK2, "$(P)$(R)yyyyyyyyy")

    field(LNK3, "$(P)$(R)zzzzzzz”)

       . . .

}

On Jun 14, 2022, at 1:20 PM, Marco A. Barra Montevechi Filho via Tech-talk <tech-talk at aps.anl.gov> wrote:

Based on this, can i assume my links are not connected yet when the first dbpfs are called? How do i debug this kind of problem?
If my links are indeed not connected and i should wait for connection, what is the EPICS recommended way of doing this?

— 

Eric Norum

eric at norum.ca