Experimental Physics and
Industrial Control System

Donny Domagoj Cosic via Tech-talk <tech-talk at aps.anl.gov> · Mon, 29 Mar 2021 13:35:08 +0200

Hello,

I am trying to calculate the rate of change of a record using a calc

record as follows:

record(ai, "$(KEIT):Charge")
{
    field(DESC, "Measure Charge")
    field(DTYP, "steam")
    field("@devKeithley6514.proto measureCharge() $(PORT)")
    field(SCAN, "Passive")
}

record(calc, "$(KEIT):CalcCurrent")
{
    field(SCAN, "1 second")
    field(INPA, "$(KEIT):Charge PP")
    field(INPB, "$(KEIT):Charge NPP")
    field(CALC, "B-A")
}

The calc record always returns 0. If I change the calc to B+A, to check

what is going on, I always get double the charge. It seems like the PP

and NPP are both returning the same value even though the actual charge

is changing. Any ideas on why this would be happening or suggestions

would be greatly appreciated.

Thank you in advance,
Donny

--
Donny Domagoj Cosic
 Institut Ruđer Bošković, Bijenička cesta 54, 10000 Zagreb, Croatia

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System