Re: What's wrong if a PV with DISA=1 still processes?

["Ned D. Arnold" <nda@aps.anl.gov>]

Dayle,

I suspect that the record is not really processing, but this does not 
stop channel access from changing the value of the VAL field.  Also, CA 
will post a monitor when it "puts", making the EDM display update. If 
the GAIN record is supposed to write to hardware, it probably didn't, 
even though the VAL field says it did ... confusing!

Set GAIN_record.TPRO = 1 in the IOC and it will show you whether the 
record processes or was disabled when you write to it.

A better solution might be to use Channel Access security rules such 
that writes to GAIN are not allowed when RUNNING.  This stops CA from 
writing to VAL and EDM should show you that writing is disallowed.

HTH -

 Ned



Dayle Kotturi wrote:
> Hello,
>
> I am using SNL to manage the operational mode of a phase and amplitude ctrllr.
> Mode is either CALIBRATING or RUNNING.
> When RUNNING, I attempt to disallow changes to gain setting via entry{}
> clause of state RUNNING where I set DISA to 1 for the gain PV.
> I can see DISA field is set correctly to 1 via dbpr.
> On the EDM GUI, however, I am still able to change the gain.
> The gain is a longout record.
>
> From the doc, I understand that when DISA==DISV==1, processing should
> not occur. Why does it?
>
> It is EPICS R3.14.8.2.
>
> Dayle Kotturi                                            dayle@stanford.edu
> LINAC Coherent Light Source                             office 650-926-4923
> Stanford Linear Accelerator Center                         fax 650-926-4778
>
>