Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Fri, 25 Jun 1999 10:48:46 -0500

Hi Steve,

Steve Hunt wrote:
> 
> Can anyone tell me what pp_value in a dbd file represents ?
> 
> does it declare the default for a link is pp or npp ?

Not quite.  It is used by PP links pointing to a field to determine
whether to process the record or not after changing the field's value. 
Think of something like the HOPR or LOPR fields - you don't usually want
to process a record just because you changed these, so PP=No.  For the VAL
field though the opposite is true, so PP=Yes.  This assumes that
SCAN=Passive of course (SCAN is another field where PP=No; when changing
it from I/O Intr to Passive say you wouldn't want a record to process).

HTH,

- Andrew
-- 
New country, job, address, car and signature; same old Andrew Johnson

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System