OPC UA Device Support - Limit in the number of PVs

[eusebio_naif AL-SOLIMAN FUENTES via Tech-talk <tech-talk at aps.anl.gov>]

Hello everyone,

I am performing some tests with the OPC UA Device Support, and I have found that there is apparently a limit to the number of PVs that can be added to the IOC.

Specifically, I am adding these two records 1000 times, where {index} is substituted by 0, 1, ... 1000:

record(calcout, "SIM:PV:DOUBLE:{index}") {
  field(SCAN, ".2 second")
  field(DESC, "counter")
  field(EGU, "Counter")
  field(HOPR, "100000")
  field(LOPR, "0")
  field(CALC, "A+B")
  field(INPA, "SIM:PV:DOUBLE:{index}.VAL NPP")
  field(INPB, "0.01")
  field(OCAL, "A")
  field(DOPT, "Use OCAL")
  field(OUT , "lo{index} PP")
}

record(ao, "lo{index}") {
    field(DTYP, "OPCUA")
    field(OUT,  "@$(SUBS) ns=2;s=SIM2.DOUBLE_{index}.DOUBLE")
}

When trying to launch the IOC with the index ranging from 0 to 2000, I experience several issues. The following errors appear in the IOC shell console:

OPC UA record lo1199 monitored item ns=2;s=SIM2.DOUBLE_1199.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1200 monitored item ns=2;s=SIM2.DOUBLE_1200.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1201 monitored item ns=2;s=SIM2.DOUBLE_1201.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1202 monitored item ns=2;s=SIM2.DOUBLE_1202.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1203 monitored item ns=2;s=SIM2.DOUBLE_1203.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1204 monitored item ns=2;s=SIM2.DOUBLE_1204.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1205 monitored item ns=2;s=SIM2.DOUBLE_1205.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1206 monitored item ns=2;s=SIM2.DOUBLE_1206.DOUBLE failed with error BadConnectionClosed
OPC UA record lo1207 monitored item ns=2;s=SIM2.DOUBLE_1207.DOUBLE failed with error BadConnectionClosed

...

lo1054 : unsupported conversion from epicsFloat64 to Null for outgoing data
lo1054 : value out of range
lo1055 : unsupported conversion from epicsFloat64 to Null for outgoing data
lo1055 : value out of range
lo1056 : unsupported conversion from epicsFloat64 to Null for outgoing data
lo1056 : value out of range
lo1057 : unsupported conversion from epicsFloat64 to Null for outgoing data
lo1057 : value out of range
lo1058 : unsupported conversion from epicsFloat64 to Null for outgoing data
errlog: lost 191 messages

I have also observed this behavior when the index limit is as low as 1005.

Thanks in advance.

Best regards,

Eusebio.

--

Eusebio N. Al-Soliman

PhD Student

Departamento de Ingeniería de Computadores, Automática y Robótica

---

University of Granada

18008, Granada, Spain | eunaif at go.ugr.es