Experimental Physics and
Industrial Control System

Hi Donny,

 

I did similar applications at NSLS-II: calculate hourly, daily, monthly, yearly cumulative beam current in the Storage Ring.

 

Here is one example to test the cumulative dosage in one minute: "DosagePV" is a simulated PV;  "Dosage:1h" is the cumulative dosage; Whenever one minute passes, the value of “TimeStamp” (@%M) will change and "Dosage:1h-Reset_" will set "Dosage:1h" to 0.

 

To calculate hourly, daily, monthly, yearly dosage, simply change %M in field(INP, "@%M") to %H, %d, %b, %Y.

 

To preserve the cumulative dosage, you should use EPICS AutoSave (info(autosaveFields_pass0, "VAL")). Otherwise, the value will be 0 after your IOC is rebooted.

 

record(calc, "DosagePV") {

    field(INPA, "DosagePV")

    field(SCAN, "1 second")

    field(CALC, "A+1")   

    field(FLNK, "TimeStamp")

}

 

record(stringin, "TimeStamp")

{

    field(DTYP, "Soft Timestamp")

    field(PINI,"YES")

    #field(INP, "@%b %d, %Y %H:%M:%S.%03f")

    field(INP, "@%M")

}

 

record(calcout, "Dosage:1h-Reset_")

{

    field(INPA, "TimeStamp CP")

    field(CALC, "0")

    field(OUT,  "Dosage:1h PP") 

}

 

record(calcout, "Dosage:1h-Calc_")

{

    field(INPA, "Dosage:1h")

    field(INPB, "DosagePV CP")

    field(CALC, "A+B")

    field(OUT,  "Dosage:1h PP") 

}

record(ai, "Dosage:1h")

{

    field(PREC, "3")

    field(EGU,  "blabla")

    field(PINI,"YES")

    info(autosaveFields_pass0, "VAL")

}

 

 

There are other ways to calculate the cumulative dosage: use compress record.

I prefer the first approach above. The approach below works only if “DosagePV” updates at a regular rate (i.e. 1Hz).

record(compress,"Dosage:1h-Com_")

{

        field(INP,"DosagePV CP")

        field(ALG,"N to 1 Average")

        field(NSAM,"1")

        field(N,"3600")

        field(PREC,"3")

        field(FLNK,"Dosage:1h_")

}

 

record(calc, "Dosage:1h_")

{

        field(INPA,  "Dosage:1h-Com_")

        field(CALC, "3600*A")

        field(PREC, "3")

}

 

 

HTH,

Yong Hu

NSLS-II Controls Group