Experimental Physics and
Industrial Control System

[email protected] (Steve Lewis) · Thu, 22 Jan 1998 13:40:13 -0800

> 
> > 
> > > 	I would prefer to have a single record for the download.  However,
> > > I'm not sure how this fits into epics.  I would like the users to perform  
> > > caputs for each of the parameters.  After all of the parameters have been
> > > filled (each would have a field in the record), the user performs 
> > > another caput to indicate that all of the parameters 
> > > have been filled and the record can process by writing to the
> > > proper vme addresses.   This is where I'm not sure how this fits into
> > > epics.  I only want the record to process (write to port card) once, even
> > > while I am performing caputs -- which as I understand causes the record to
> > > process.
> > 
> > I'd do this with a subroutine record.  The input parameters would go to ao 
> > records, which would hold the paramenters until the subroutine record 
> > processed, but _not_ be out-linked or forward-linked to the subroutine record. 
> > The subroutine record would reference the ao's through the inpa through inpl 
> > fields.  The subroutine record could be made to process by a caput to the PROC 
> > field.  The subroutine code would download the chips based on the input 
> > parameters which would appear in the a-i fields.
> > 
> > 	Carl
> 
> 
> You could eliminate the ao records and write the parameters directly to
> the subRecord.a thru subRecord.i (even initialize them in the database). 
> Although writing values to these fields will cause the record to process,
> your subroutine could be smart enough to not use the data until a 1 was written
> to subRecord.L. Internally, you could keep track of whether you had downloaded
> the parms, so as to do it only once.

But the advantage of the "extra" ao's is they have their own
HI/LO limits, units, other constraints so display widgets and
so forth work well.  The A-L inputs of the sub record are rather
anonymous.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System