Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Tue, 30 Jan 2018 13:13:37 -0600

Hi Simon,

On 01/30/2018 10:20 AM, Simon Reiter wrote:
> Up to now, my event record has an INP field, which links to a calc record.
> This calc record only provides the correct value under some conditions.
> How can I do this without using a state machine?
> 
> record(calc,"$(BOARDNAME):ErrorFlags:calc")
> {
>   field(INPA, "$(BOARDNAME):InitDone:S CPP")
>   field(CALC, "A ? 2 : 0")
> }
> 
> record(event, "$(BOARDNAME):ErrorFlags:trg")
> {
>   field(INP,  "$(BOARDNAME):ErrorFlags:calc CPP")
> }
> 
> This is my current code. The value of event is now 2.000000 in the
> correct case.

For conditional processing of your event record I would recommend using
the SDIS input link and DISV field which all records have, something
like this:

record(event, "$(BOARDNAME):ErrorFlags:trg") {
    field(VAL, "2")
    field(SDIS, "$(BOARDNAME):InitDone:S CPP")
    field(DISV, 0)
}

This keeps the event name/number associated with the record rather than
having to go looking at the calc record to work out which event(s) it
might trigger, and it only needs the one record.

See
https://wiki-ext.aps.anl.gov/epics/index.php/RRM_3-14_dbCommon#Scan_Fields
for a description of the scan disable mechanism.

You might have to adjust the value of the DISV field depending on what
your $(BOARDNAME):InitDone:S record actually returns.

HTH,

- Andrew

-- 
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System