devSnmp, device replying with a string containing units

[Andrea Celentano via Tech-talk <tech-talk at aps.anl.gov>]

Dear colleagues, 

I have a device that can be programmed using SNMP (Wiener MPOD crate). 

A typical reply to the command:

snmpget  -v 2c -m +WIENER-CRATE-MIB -c guru 10.152.72.10 outputVoltage.u0

Looks as:

WIENER-CRATE-MIB::outputVoltage.u0 = Opaque: Float: 0.000000 A

Where, as you see, the device replies with the number (0.0000) containing also units (A)

My record to read this is:

record(ai, “wienerCh0:v")

{

  field(DESC, “Voltage")

  field(DTYP, "Snmp")

  field(SCAN, "$(SCAN)")

  field(PREC, "3")

  field(EGU,  “V")

  field(INP,  “@10.152.72.10 guru WIENER-CRATE-MIB::outputVoltage.u0 Float: 100")

  field(ADEL, "1.0")  

}

If I execute my IOC, I get the error:

2025/03/06 15:00:49  devSnmp AI read error 'wienerCh0:v' : epicsScanDouble failed on '5.000000 V'

As if the IOC is not able to parse the “Volt” units. And indeed, the PV is not properly populated:

caget wienerCh0:v

wienerCh0:v            0

May I ask you if any of you also faced this issue? 

Thanks,

Andrea