position compare without encoder

[deltaa]

Anyone has experience on how to setup position compare function for Geo Brick LV direct microstepping mode without using encoder? Thanks.

[Sina.Sattari]

The mircostepping uses a simulated feedback in the Turbo PMAC's memory and doesn't use any of the DSPGate1 ASIC functionality which position compare is one of them. If you want to do a position compare, the best way is to set up a virtual motor using an internal pulse and direction on one of the available channels on one of your DSPGate1 ASIC(s) and set it as a slave to your microstepped channel and perform all the position capture on the virtual axis.

 

I hope this helps.

[deltaa]

The mircostepping uses a simulated feedback in the Turbo PMAC's memory and doesn't use any of the DSPGate1 ASIC functionality which position compare is one of them. If you want to do a position compare, the best way is to set up a virtual motor using an internal pulse and direction on one of the available channels on one of your DSPGate1 ASIC(s) and set it as a salve to your microsteped channel and perform all the position capture on the virtual axis.

 

I hope this helps.

 

Trying to use motor #1 for direct micro stepping and motor #4 as the virtual motor with internal pulse & direction wrapped back, with the following setup, both motors work fine individually.

 

; ECT for motor #1

I8000=$6800BF

I8001=$10020

I8002=$EC0009

; ECT for motor #4

I8003=$C78018

;virtual motor #4

I400=1

I401=0

I402=$7801C

I403=@I8003

I404=@I8003

I405=@I8002

I406=1

I7040=8

I7046=3

 

When trying to move motor #4 along, position compare works no problem. When enable position following on #4 and moving motor #1, position compare does not work. It seems motor #4 does not "follow". What could be wrong?

 

Thanks

[curtwilson]

Your setting for I8002 ($EC0009) is integrating the result for I8009, and it should be integrating the result for I8001 (the velocity command for Motor 1), so it should be set to $EC0001.