Hi,
We are using our Galil DMC-4030 configured to control a stepper motor as a slave axis. The master axis is another encoder and we have set a gear ratio of 2 for the slave axis to be 2x the speed of the master axis. This all seems to work very well, and is much more stable than when had it configured as a servo-motor.
What we have not been able to achieve is to use the IP Increment Position , or PR Position Relative commands, when in a stepper motor configuration, to adjust the relative phase angle between the two axes whilst they are moving.
We have been able to achieve this when the DMC-4030 is operating in a servo-motor configuration, just not when operating in a stepper motor configuration.
Is the Galil DMC-4030 capable of adjusting the relative phase using IP or PR when in stepper motor configuration?
Cheers
Carl
cqhoward on 02/21/2016 - 17:45
We were able to solve the issue. Yes the Galil can controller a stepper motor using a gear ratio and increment position. The issue was that there was a missing SP speed command for the axis. .. When running in servo motor mode, the Galil controller can use the JG jog command when using the IP increment position command. However, the JG jog command is not recognised when using the Galil in stepper motor control. The alternative is that one must use the SP speed command. In our case, issuing the command SPA=1000 solved the problem (we took 4 days to figure this out!).
For interest, we are able to increment IPA=+1000 and decrement IPA=-1000 the relative position whilst the motor is spinning.
It appears that when the SPA=1000 command is issued, followed by the IPA=1000 command (when running in a geared ratio GRA=30), the speed of the stepper motor will temporarily increase from the nominal speed to +1000 counts/sec, until it has caught up to the desired position, and then will decrease in speed back to the nominal speed.
cqhoward on 02/21/2016 - 17:48
a minor correction to my comment - it looks like one cannot edit posts on the forum.
"... the speed of the stepper motor will temporarily increase from the (nominal speed) to (nominal speed +1000) counts/sec, until it has caught up to the desired position, and then will decrease in speed back to the (nominal speed +0) counts /sec.