Experimental Physics and
Industrial Control System

Kevin Peterson via Tech-talk <tech-talk at aps.anl.gov> · Tue, 14 Nov 2023 09:48:10 -0600

Phi,

I'm not able to reproduce the problem of the motors staying at 1 on

subsequent 1-unit relative moves.

I do see errors in the positions after the 2nd move following a reset of

motor positions to zero. Here is the camonitor output for three

relative 2-unit moves:

$ camonitor kmp3:test:m1.VAL kmp3:m{1,2,3}.VAL
kmp3:test:m1.VAL               2023-11-14 09:27:07.187920 0
kmp3:m1.VAL                    2023-11-14 09:27:07.122334 0
kmp3:m2.VAL                    2023-11-14 09:27:07.155012 0
kmp3:m3.VAL                    2023-11-14 09:27:07.274250 0

kmp3:m1.VAL                    2023-11-14 09:27:41.662214 2
kmp3:m2.VAL                    2023-11-14 09:27:41.662305 2
kmp3:m3.VAL                    2023-11-14 09:27:41.662371 2
kmp3:test:m1.VAL               2023-11-14 09:27:41.662412 2

kmp3:m1.VAL                    2023-11-14 09:27:50.711933 6
kmp3:m2.VAL                    2023-11-14 09:27:50.712022 6
kmp3:m3.VAL                    2023-11-14 09:27:50.712092 6
kmp3:test:m1.VAL               2023-11-14 09:27:50.712132 4
kmp3:m1.VAL                    2023-11-14 09:27:53.170613 4.21
kmp3:m2.VAL                    2023-11-14 09:27:53.170687 4.21
kmp3:m3.VAL                    2023-11-14 09:27:53.170748 4.21

kmp3:m1.VAL                    2023-11-14 09:28:05.077614 10.21
kmp3:m2.VAL                    2023-11-14 09:28:05.077647 10.21
kmp3:m3.VAL                    2023-11-14 09:28:05.077673 10.21
kmp3:test:m1.VAL               2023-11-14 09:28:05.077689 6
kmp3:m1.VAL                    2023-11-14 09:28:07.302760 6.21
kmp3:m2.VAL                    2023-11-14 09:28:07.302867 6.21
kmp3:m3.VAL                    2023-11-14 09:28:07.302960 6.21

Note: kmp3:test:m1 is my soft motor and kmp3:m{1,2,3} are my "real" motors.

I suspect the error that is introduced is much smaller for you because

the galil support using a much higher moving poll frequency that my

simulated motors.

Changing the $(P)-F fanout so that it outputs to the real motors' VAL

fields instead of their RLV fields remains the simplest solution. This

is what the same series of 2-unit relative moves looks like after that fix:

$ camonitor kmp3:test:m1.VAL kmp3:m{1,2,3}.VAL
kmp3:test:m1.VAL               2023-11-14 09:21:57.513328 0
kmp3:m1.VAL                    2023-11-14 09:21:28.188527 0
kmp3:m2.VAL                    2023-11-14 09:21:28.232332 0
kmp3:m3.VAL                    2023-11-14 09:21:28.264741 0

kmp3:m1.VAL                    2023-11-14 09:22:08.629501 2
kmp3:m2.VAL                    2023-11-14 09:22:08.629531 2
kmp3:m3.VAL                    2023-11-14 09:22:08.629542 2
kmp3:test:m1.VAL               2023-11-14 09:22:08.629561 2

kmp3:m1.VAL                    2023-11-14 09:22:14.873323 4
kmp3:m2.VAL                    2023-11-14 09:22:14.873386 4
kmp3:m3.VAL                    2023-11-14 09:22:14.873428 4
kmp3:test:m1.VAL               2023-11-14 09:22:14.873488 4

kmp3:m1.VAL                    2023-11-14 09:22:26.848583 6
kmp3:m2.VAL                    2023-11-14 09:22:26.848654 6
kmp3:m3.VAL                    2023-11-14 09:22:26.848695 6
kmp3:test:m1.VAL               2023-11-14 09:22:26.848722 6

If you really need the real motors to do relative moves, you'll need to

add records in between the soft motor and the fanout to convert the

absolute position, which is written to the PV in soft motor's OUT field,

into a relative displacement. I don't have good suggestions how to

implement that.

Kevin

On 11/13/23 16:46, Tran, Phi Dung wrote:

Hi Kevin,

I am using my Soft Channel $(P) to move my three real motors by relative

motions.

I set the field(RTRY,0) in $(P).  Initially, I set all three real motor

positions or xxx.VAL to zero.

Next, I caput $(P)  1 for relative motion for the real motors.  All real

motors moved to 1+0 from 0 for relative move, xxx.RLV.

_However, all subsequent caput $(P) 1 will not cause the real motors to

move from 1.  They stayed at 1 instead of 1+1?_

If I set all three real motor positions Xxxx.VAL to zero again.
First caput $(P) 2.  All three real motors moved relatively to 2+0 from 0.

_Second caput $(P) 2.  All three real motors moved relatively to

2.000,2.001,2.002 not 4,4,4._

Third caput $(P) 2.  All three real motors moved relatively to

4.000,4.001,4.002.

All subsequent caput $(P) 2, correctly moved the motors to the

additional 2 units relative to the current positions.

Please advice.
Thank you,
Phi

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System