RE: questions about stepper motor

["Mark Rivers" <rivers@cars.uchicago.edu>]

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.

 

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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