Re: questions about stepper motor

[Pete Jemian <prjemian@gmail.com>]

Documentation for the EPICS motor record can be found starting from this URL
http://www.aps.anl.gov/bcda/synApps/motor/
and then navigate by version.


Mark Rivers wrote:
> HOMF and HOMR are set to 1 to home the motors in the Forward or 
> Reverse directions.
>
> JOGF and JOGR are set to 1 to jog the motors (i.e. move them 
> continuously until JOGF or JOGR are set back to 0).
>
> You should have them set to 0 when the IOC boots.
>
> I hve never tried moving a motor for months. The only problem I can 
> think of is soft limits; I’m not sure if those can be disabled.
>
> ------------------------------------------------------------------------
>
> *From:* tech-talk-bounces@aps.anl.gov 
> [mailto:tech-talk-bounces@aps.anl.gov] *On Behalf Of *Xu, Huijuan
> *Sent:* Wednesday, November 26, 2008 2:04 PM
> *To:* tech-talk@aps.anl.gov
> *Subject:* questions about stepper motor
>
> Hello,
>
> I’m new to motor stepper and I’d like to ask some questions.
>
> I’ve read the motor record and I’m not sure I can get what the HOMR, 
> HOMF, JOGR, JOGF means. What are they used for?
>
> I thought HOMR/HOMF has some relation with LLM/HLM respectively. Is 
> that right? If is, what’s the relation? What about JOGF/JOGR?
>
> In the motor record documentation, it says ‘these fields can be set to 
> 1, but setting either field to 0 results in an error’. What kind of 
> error it may cause? I found that in the IOC initialization, no values 
> are set to these field, that means the default value 0 is used. And 
> then when the HOMR or HOMF is clicked(motorx_all.adl), such error occurs:
>
> Filename=”../devOmsCom.cc” line number=404
>
> Overriding invalid velocity; slew<=base.
>
> Even if the HOMF and HOMR are set to 1, the same error occurs. Thus I 
> thought this error is not caused by the settings of HOMF and HOMR. I 
> thought it was caused by the velocity is too slow even smaller than 
> the base velocity. But I don’t know how to solve it. The motor and 
> motion related fields are set as follows in my situation.
>
> MRES=0.18 UREV=360 SREV=2000 VELO=20 S=0.0555556 VBAS=2
>
> The MD125 microstep drive is used and the step rate is 10. I’d like to 
> know how to solve this problem.
>
> The above error will not affect the running of the motor. But when the 
> JOGF/JOGR is used, a fatal error occurred.
>
> FATAL: unrecoverable exception without a task context.
>
> The error displayed on MEDM is:
>
> Channel Access Exception:
>
> Channel Name: Unavailable
>
> Native Type: Unavailable
>
> Native Count: 0
>
> Access: Unavailable
>
> Message: Virtual Circuit unresponsive
>
> Context: 192.168.2.105:5064
>
> Requested Type: TYPENOTCONN
>
> Requested Count: 0
>
> Source File: ../tcpiiu.cpp
>
> Line Number: 921
>
> The JOGF and JOGR are not set in initialization. The default value 0 
> are used. Even changed after initialization, the same error still occurs.
>
> I will evaluate the performance of the stepper motor. When doing this, 
> I want to keep the motor moving all the time for several months. Is 
> there anyone who did the similar thing before? I can’t find any 
> reference to continuous motion. The files I was given had very little 
> in the way of documentation. The 
> http://www.aps.anl.gov/xfd/SoftDist/swBCDA/recMotor.html used to be 
> the developer documentation. But I can’t find it now.
>
> Is there anyone know? Thanks.
>
> Huijuan

--
----------------------------------------------------------
 Pete R. Jemian, Ph.D.                <jemian@anl.gov>
 Beam line Controls and Data Acquisition, Group Leader
 Advanced Photon Source,   Argonne National Laboratory
 Argonne, IL  60439                   630 - 252 - 3189
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    Education is the one thing for which people
       are willing to pay yet not receive.
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