Re: Motor Record OMSL field

[Ron Sluiter <sluiter@aps.anl.gov>]

Hello again EPICS motor record users,

I received one strong objection to removing the OMSL field
from the motor record, so my alternative is to remove it from
the one medm display distributed with the motor record
distribution in which it appears.

This comes from the "if you don't see it, you can't accidentally
mess it up" school of engineering.

Ron


Ron Sluiter wrote:
> Hello EPICS motor record users,
>
> Has anyone used (or is currently using) the motor record with the
> OMSL field  set to "closed-loop"?
>
> If not, I plan on removing it from the motor record with the next
> "major" release (i.e. R6-5).
>
> Here at the APS, we use save/restore to preserve the motor record's
> DVAL through a reboot or power-cycle.  Setting the OMSL to
> "closed-loop" has the undesirable effect of  preserving DVAL,
> but leaving the VAL and RVAL fields to their default values; zero.
> Since incremental moves (tweaks) are done from user coordinates
> (i.e. the VAL field), an incremental move after a reboot would
> cause the motor to move, unexpectedly, to near the zero position.
>
> Since I am unaware of any use for the OMSL field to be set to
> "closed-loop", I strongly recommend that motor record users leave
> this field in its' default "supervisory" state.
>
> Ron