Re: Altering motor resolution via MRES field

[Kevin Peterson via Tech-talk <tech-talk at aps.anl.gov>]

Marco,

Please run the following command on the ioc shell and share the output 
for the relevant axis:
  asynReport 1 Hydra1

The info printed by the axis report method is likely to be relevant:


https://github.com/epics-motor/motorMicos/blob/1d643c3c50c7c798a44f2e6d7806721eac8b136c/micosApp/src/SMChydraAxis.cpp#L78-L87

Kevin

On 11/10/22 06:51, Marco A. Barra Montevechi Filho via Tech-talk wrote:
> Hello all,
>
> We are using a micosIOC (https://github.com/epics-motor/motorMicos.git 
> <https://github.com/epics-motor/motorMicos.git>) to control an UPR-160 
> motor: 
> https://www.pi-usa.us/fileadmin/user_upload/pi_us/files/product_datasheets/Air_Bearing_Rotation_Stages_UPR-Air_Family.pdf 
> <https://www.pi-usa.us/fileadmin/user_upload/pi_us/files/product_datasheets/Air_Bearing_Rotation_Stages_UPR-Air_Family.pdf> 
>
> According to the motor technical data, its resolution can go down to 
> 0.00004 degrees. The current IOC has a motor with .MRES=0.04 deg, so we 
> cant make movements smaller than this. When i caput MRES to 0.004, i can 
> caput .VAL from 0.1 to 0.105, for example, and the motor will move.
> However, although the .RBV shows the movement incrementing 0.005 
> degrees, the actual observed movement is of 0.05 degrees. In other 
> words: changing the motor MRES to ten times lower makes the motor move 
> ten times more than what is commanded.
> We (me and Augusto Horita) also tried using 
> the SMChydraChangeResolution("Hydra1", 1, 0.004) function and leaving 
> MRES as 0.004 in substitutions, but the same behavior was found.
> Am i doing something wrong?
>
> Thanks for any help,
>
> Marco