Experimental Physics and
Industrial Control System

Kevin Peterson via Tech-talk <tech-talk at aps.anl.gov> · Tue, 16 Feb 2021 14:09:12 -0600

Dean,

Disclaimer: I'm not an expert in delta tau controllers.

EPICS motor drivers usually only report that an axis is moving if the

axis status query for the controller reports that an axis is moving.

Does the axis have an encoder? How stable is the feedback position when

the motor isn't moving?

I suggest looking at MIP (motion in progress) field of the motor record.

 If the motor record expects a move to be done, but MOVN is still 1,

the motor record turns on the 0x8000 (external move) bit of MIP.

Kevin

On 2/16/21 10:32 AM, Hidas, Dean via Tech-talk wrote:

Dear EPICS Experts,

I'm using pmacAsynCoord with a pmac turbo2 brick controller.  What I notice is that occasionally the pmac reports that a move is finished, that the coordinate system is not motion, but the .MOVN field of the motor record stays high despite reaching the desired position and not actually being in motion.  At this point the pmac reports in position, but the motor record does not seem to have any additional control effect (nor should it I believe), ie the .MOVN field stays high but there is no further motion.  Are there any motor record fields or other parameters you might advise having a look at that could have an effect on this?

Thank you in advance for your help,

-Dean Hidas

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System