Experimental Physics and
Industrial Control System

Ron Sluiter <[email protected]> · Wed, 26 Sep 2012 10:25:28 -0500

On 09/26/2012 09:41 AM, [email protected] wrote:

Hi,

One caveat.. Make sure the ERES field is set correctly before switching UEIP (normally it would be the same as MRES). Otherwise you can get into a mess because the motor record attempts to do a 'set position' each time UEIP is switched. So if ERES is wrong it would set an incorrect number of counts on the controller.

I think the logic there is something to do with wanting to keep RBV the same number if you switch UEIP.

Matt's comments are correct except for the last statement about the motor record
trying to keep the RBV the same with UEIP is switched.  The motor record uses the
DVAL with the "set position" command. That results in the encoder being set based
on the commanded position (DVAL/VAL/RVAL).

Some people have commented that this logic is backwards, i.e., that when UEIP
is toggled the motor record should use the readback postion (DRBV/RBV/RRBV)
when setting the position. This way toggling UEIP would synch the command
position with the readback and not change the encoder's value.

I agree and I plan on changing it in a future release.

Ron

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System