Experimental Physics and
Industrial Control System

"Ernest L. Williams Jr." <[email protected]> · Fri, 16 Jul 2010 07:29:30 -0700

Ron Sluiter wrote:

Hello Ernest,
There is a feedback data flow diagram here
<http://www.aps.anl.gov/bcda/epicsgettingstarted/specialtopics/motor1up.pdf>
on page #17 that may clarify how the motor record feedback works.

Hi Ron,
Thanks for the reference.

This confirms how I thought "DRBV/RBV" is updated with respect to the
state of "URIP".
After a move is completed, then we toggle URIP back and forth to observe
the behavior of "MOTOR.RBV".

We observe that the LVDT value does not follow.

Is this because the latest reading from the LVDT will only show up after
another move is executed?
My question arises as a result of how the motor record processes. 

Thanks for your help.
We will checkout the latest motor record software and do more testing.

Cheers,
Ernest

Ron
Ernest L. Williams Jr. wrote:

Hi,
We are currently using "Motor Record Version 5.9"
on some of our stepper motor applications.
We would like to use the motor software with USE READBACK enabled.
We are connecting our calibrated LVDT to the READBACK link.
What has been your experience in using this feature of the Motor Record?

When using READBACK inlink for Motor position sensing:
(1) Selecting YES/NO does not update the motor record properly.
Should the software actually copy the contents of MOTOR.VAL to MOTOR.RBV
If READBACK is toggled back to "NO"
If the READBACK is set to "YES" then "MOTOR.RDBL", should be copied
to MOTOR.RBV ?

Thanks in Advance,
Ernest
SLAC

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System