Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Fri, 19 Aug 2011 10:18:21 -0500

Hi Jay,

On 2011-08-19 Jay Steele wrote:
>      I also tested the ca_put_callback function to set the VAL field for
>  asyn motors, and only received the callback after the motor finished
>  moving to its command position. Is this expected behavior? I was hoping
>  for the callback to be received once the VAL field was set. Is there a way
>  to configure the channel access software to make this happen?

If you want to know when the VAL field has been set you should be able to use 
ca_create_subscription() to monitor that or some other related record field.  
One problem with using the motor.VAL field though is that it's used as both an 
input (the user's demand position) and an output field (the current position), 
so you'd get monitor events while the motor is moving.  That might not be what 
actually want, so you should look at the other fields available and see if 
monitoring one of them might be more appropriate for your purposes.

- Andrew
-- 
Optimization is the process of taking something that works and
replacing it with something that almost works, but costs less.
-- Roger Needham

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System