Experimental Physics and
Industrial Control System

"Silver" <[email protected]> · Mon, 20 Jun 2011 22:42:07 +0800

hi, 

I am using stream device driver to communicate a galil motion control which model is dmc21x3. To  get the value of optical scale, I use a ai record like this:

record(ai,"$(PREFIX):opticalscale")
{
        field (DESC, "opticalscale position")
        field (DTYP, "stream")
        field (INP, "@dmc2143.proto ai_opticalscale motor")
        field (SCAN, ".5 second")
}
In that, I use the period scan. It works fine.
But in most of time, the value doesn't change. That means the IOC has to communicate with device periodly. As the value only changes during the motor moving,  may I use I/O Intr mode? 
I checked the online document of stream device, seems the I/O Intr mode is not suitable for this case. Is there any good ways to avoid checking the devcie periodly?
Thanks a lot for your help.

Best regards
Geyang  2011-06-20

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System