Experimental Physics and
Industrial Control System

[email protected] (John R. Winans) · Fri, 16 Aug 1996 10:38:15 -0500

>I've got a situation where I need to cause a PV to process when a second
>PV makes a transition in one direction.  In otherwords, I need to fire
>PV1 when PV2 changes state 1->0, but not on the 0->1 change.  If it matters,
>PV1 is a BO to a GPIB device.  A particularly ugly GPIB device, at that.
> 
>I'm sure I've seen this done (short of writing a state machine in SNL),
>but it escapes me.  Probably just another case of "Berkeley Brain Rot."

I have not looked at a database in a long time, but...

Would not the scan disable take care of this?  You could simply set PV1's
disable value to be 1 from PV2 and then forward link from PV2 to PV1.

--John Winans

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System