Motor record RES field usage.

['Ronald L. Sluiter' <sluiter@aps.anl.gov>]

I plan on removing the RES field from the next release
(R4.5) of the motor record (see below for why?).

The RES field is used in the SGM.db, which is
distributed with the synApps.

Does anyone have any other applications that use the
motor record RES field?

Unfortunately, this change will make any clients that
currently use the RES field incompatible with the new
motor record release.

The solution is to replace RES with MRES.  But, then
those applications will be incompatible with previous
motor record releases.

If there are many such applications (besides SGM.db),
then I will simply preserve the RES field for backward
compatibility.

Why drop RES?
Currently, the RES field is set to either
ERES or MRES, based on whether or not the
following statement is true; MSTA indicates
an encoder is present, AND, UEIP is set to YES.

This state (i.e., MSTA indicates an encoder
is present, AND, UEIP is set to YES) results
in the record converting all position derived
values from EGU's to raw encoder counts before
sending them to the motor controller.

This is the manner in which the OMS controllers
work (see OMS User's Manual, ER# command).  Hence,
only the OMS controllers work in this state.  With
the next release, all raw positions, velocities and
accelerations will be in terms of motor steps.