Experimental Physics and
Industrial Control System

Kevin Peterson via Tech-talk <tech-talk at aps.anl.gov> · Tue, 1 Nov 2022 10:23:26 -0500

Marco,

The motor record will tell device support to send relative move commands

with displacements relative to the readback position, instead of

absolute move commands, to the controller if the following conditions

are met:

1. RTRY != 0
2. RMOD != "In-Position"
3. UEIP = YES or URIP = YES

The default RMOD setting is not "In-Position", so all that should be

required is to set RTRY > 0 and set UEIP = YES (assuming ERES is set

correctly).

It is important to note that not all drivers implement relative moves

(motorPIGCS2 is the first that comes to mind).

Kevin

On 10/28/22 14:40, Marco A. Barra Montevechi Filho via Tech-talk wrote:

Hello all!

Im reading through the EPICS motor record to search for a field similar

to .RLV. If i understand correctly, the .RLV will do something similar

to summing the caputted value to .VAL instead of directly putting it

into .VAL.

Is there a field that sums itself with .RBV instead and then puts this

value into .VAL?

Example of expected behavior:

caget MOTOR.RBV
MOTOR.RBV         0.5
caget MOTOR.VAL

MOTOR.VAL         2  #Lets say that for some reason .VAL and .RBV are

not in sync.

caput MOTOR.MISTERIOUS_FIELD 0.5

#wait for some time...

caget MOTOR.RBV
MOTOR.RBV            1
caget MOTOR.VAL
MOTOR.VAL             1

Sorry if the question is trivial but i couldnt find anything in the

documentation. Thanks!

Marco

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System