Hi Mi Qingru,
As Mark said yesterday, I think this would be solved by a move to a new model motor driver which will not wait forever since the status will be updated by the
next motor poll.
According to PI website, the PI-C863 supports the PI General Command Set (GCS). PI themselves have written an “Model 3” asyn port based EPICS motor driver for
GCS motor controllers called PI_GCS2 (don’t get confused by the PI motor support in the motor module – these say they are asyn drivers, but this just means they you asyn for RS-232 communication, they aren’t asyn motor drivers). I think the PI written driver
supports the PI-C863, so I think the driver you need exists.
I can’t find the driver on the EPICS hardware support downloads page, but I found this tech talk reference from Steffen Rau (the PI developer):
http://www.aps.anl.gov/epics/tech-talk/2012/msg02398.php
which says they are available on sourceforge at:
http://sourceforge.net/projects/piasyn/. If that fails, I have a snapshot from the middle of last year that I can pass on.
I would suggest that you download and try this driver before trying anything else....
Cheers,
Nick Rees
Principal Software Engineer Phone: +44 (0)1235-778430
Diamond Light Source Fax: +44 (0)1235-446713
From: [email protected] [mailto:[email protected]]
On Behalf Of Mi Qingru
Sent: 30 May 2013 09:14
To: tech-talk epics
Subject: PI C863's direction status can't change in time as leaving the limit switch
After the motor drived by PI C863 hit the limit switch and stopped, it would be commanded to leave the limit switch and should move in reverse direction. But the motor record
often stopped immedietely as the moving started, and the motor actually did move on the command. The motor record seemed to restart after the “STOP/GO” button is pressed. Sometimes the button didn’t work too.
The debug information showed that the direction status and the limit switch status in C863 couldn’t change when the motor record queried C863 first time. So the motor record
thought no motor in moving , then wait forever. Even if we reduced the scan rate, the problem still occurred. The engineer from PI told us the time in which the direction status changed was not sure, and it depended on the difference between the current position
and the origin position from the encoder.
Is there any ways to resolve the problem?
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