Experimental Physics and
Industrial Control System

"Konrad, Martin" <[email protected]> · Mon, 29 Jul 2013 19:18:09 +0000

Hi,
> I tested the OMS-58 and MSTA does update if the limit is disconnected
> and STUP is set to 1.
Mark, thanks for providing these details. With your information I was
able to track the issue further down:
Even with the "sendMsg = false;" line commented out in the device
support, the MSTA field does not show a change in the limit-switch
status while the motor is stopped (as far as I can see commenting out
this line has no effect on the behavior at all).

Sniffing the TCP connection between the IOC and the motor controller I
learned that the issue is caused by the behavior of the motor controller
which only transmits some sort of a "limit switch hit while moving"
status as a response to the TAS (transmit axis data) command. In other
words: The limit status in this message is not updated while the motor
is stopped and triggering STUP is pretty useless (at least regarding the
limit switches)...

Nevertheless it is possible to read out the state of the limit inputs
with the TLIM (transmit limits) or LIMFNC (input function for limit
inputs) commands. Here is an example:
# all limit switches in "ok" position:
> TAS
*TAS0000_0100_0000_0001_0000_0000_0000_0000
> 
> TLIM
*TLIM110
> 
> LIMFNC
*LIMFNC1-R POS LIMIT INPUT       - STATUS ON
*LIMFNC2-S NEG LIMIT INPUT       - STATUS ON
*LIMFNC3-T HOME LIMIT INPUT      - STATUS OFF

# negative limit switch pressed (while motor stopped):
> TAS
*TAS0000_0100_0000_0001_0000_0000_0000_0000
> 
> TLIM
*TLIM100
> 
> LIMFNC
*LIMFNC1-R POS LIMIT INPUT       - STATUS ON
*LIMFNC2-S NEG LIMIT INPUT       - STATUS OFF
*LIMFNC3-T HOME LIMIT INPUT      - STATUS OFF

As far as I can see the PC6K device support should use one of TLIM or
LIMFNC to determine the status of the limit switches. Can anyone of the
maintainers confirm that? - I don't want to make changes to the code
that do not have a chance to be included into the next version of motor
record...

Thanks for your help,

Martin

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System