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<== Date ==> <== Thread ==>

Subject: Re: second relative motion stuck in a do loop
From: Kevin Peterson via Tech-talk <tech-talk at aps.anl.gov>
To: "Tran, Phi Dung" <ptran1 at bnl.gov>, "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Date: Thu, 9 Nov 2023 16:29:32 -0600
Phi,

I see a number of problems with the database:

1. The SCAN field of the $(P) motor should be "Passive", not "PASSIVE" -- this causes an error but is not the source of the problem.

2. The $(P) motor isn't setting RTRY, so the number of retries is defaulting to 10. If you set RTRY to 0, the outboard, inboard, and downstream motors will only be moved once, instead of what appears to be in a loop.

3. The $(P) motor's OUT field is writing the motor's TARGET position to the $(P)-F fanout, but the $(P)-F fanout is writing to the output, inboard, and downstream motor's RLV field, but it should be outputting to their VAL fields.

If all the motors are at zero and the virtual motor does a relative move of any distance, the move should complete successfully because an absolute move and a relative move are the same, when starting from zero.

If the real motors have non-zero positions, requesting a 1mm relative move of the virtual motor, commands a relative move of the real motors with a magnitude of 1mm plus the virtual motor's current position.

If the virtual motor has a non-zero number of retries, the motor record does a retry at the end of the move because the readback position of the virtual motor doesn't match the desired target position.

Kevin

On 11/9/23 12:58, Tran, Phi Dung wrote:
Hi Kevin,

Here is the result.
If I caput my virtual motor $(P) by 1 then $(P)-F will fanout to my three real motors.  The three motors move by 1 and their X.Mtr.VAL is at 1.  If I repeat caput by 1 many times to my virtual motor, the three real motor VAL remains at 1.

However when I caput 2 to my virtual motor, the three motors moved to 20.1 mm.

Here is the output,

[ptran1@xf19id2-ws3 ~]$ caput XF:19IDC-ES-G0{Ymove}Mtr.TPRO 1

Old : XF:19IDC-ES-G0{Ymove}Mtr.TPRO0

New : XF:19IDC-ES-G0{Ymove}Mtr.TPRO1

[ptran1@xf19id2-ws3 ~]$ caput XF:19IDC-ES-G0{Ymove}Mtr-F.TPRO 1

Old : XF:19IDC-ES-G0{Ymove}Mtr-F.TPRO 0

New : XF:19IDC-ES-G0{Ymove}Mtr-F.TPRO 1

_Input 1, caput XF:19IDC-ES-G0{Ymove}Mtr 1, all three real motors moved to 1_

ca:ptran1 at xf19id2-ws3.nsls2.bnl.local: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

ca:ptran1 at xf19id2-ws3.nsls2.bnl.local: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-F'

CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

…. Multiple repeat of CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

….

scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'

CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'

CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'

CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

_Input2, caput XF:19IDC-ES-G0{Ymove}Mtr 1, all 3 real motors previously at 1, they remained at 1 and all_

_Subsequent input of 1 will not move the 3 real motors and only dbProcess is shown._

ca:ptran1 at xf19id2-ws3.nsls2.bnl.local: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

_Input3, caput XF:19IDC-ES-G0{Ymove}Mtr 1, all 3 real motors previously at 1, they remained at 1 and all_

_Subsequent input of 1 will not move the 3 real motors and only dbProcess is shown._

ca:ptran1 at xf19id2-ws3.nsls2.bnl.local: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'

_Input4, caput XF:19IDC-ES-G0{Ymove}Mtr 2, all 3 real motors previously at 1, they moved to 20.1_

_ca:ptran1 at xf19id2-ws3.nsls2.bnl.local: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'_

_ca:ptran1 at xf19id2-ws3.nsls2.bnl.local: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-F'_

_scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'_

_scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'_

_scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'_

_CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'_

_…._

_CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'_

_scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'_

_CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'_

_scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'_

_CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'_

_scanOnce: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr-DMOV'_

_CAC-event: dbProcess of 'XF:19IDC-ES-G0{Ymove}Mtr'_

Thanks,
Phi
------------------------------------------------------------------------
*From:* Kevin Peterson <kmpeters at anl.gov>
*Sent:* Thursday, November 9, 2023 11:04 AM
*To:* Tran, Phi Dung <ptran1 at bnl.gov>; tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
*Subject:* Re: second relative motion stuck in a do loop
Phi,

Are any of the motors (real or soft) doing retries?

How does the $(P)-DMOV record's behavior differ between the 1st relative
move, which succeeds, and the 2nd relative move, which misbehaves?

Kevin

On 11/7/23 22:23, Tran, Phi Dung via Tech-talk wrote:
Hi,

I am using RLV for relative motion with a soft channel. When I issue a caput command with a value of 2 to my soft channel, $(P), to move the other real motors, they move by 2 mm. However, when I repeat the caput command with the value 2 to my soft channel for the second time, the motors move by 7*2=14 mm instead of 2 mm. Please advise.

Thank you,
Phi


Replies:
Re: second relative motion stuck in a do loop Tran, Phi Dung via Tech-talk
References:
second relative motion stuck in a do loop Tran, Phi Dung via Tech-talk
Re: second relative motion stuck in a do loop Kevin Peterson via Tech-talk
Re: second relative motion stuck in a do loop Tran, Phi Dung via Tech-talk

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