Phase Drive Questions

Hello,

I am converting a system that ran on TURBOCNC with MotionGroup hardware. One of the quirks of this setup is its phase drive.
Basically the way I' reading the existing TURBOCNC parameters the 2 pins going to any motor needs to fire in this order 1,1-1,0-0,0-0,1 Using stepgen parameter 5 has gotten me the smoothest(nearly acceptable) results. In forward the motor runs rather notchy but in reverse its very smooth.

But as you can see in the attached HAL I am only using phases A and B. If I could tie a certain phase to both pins so that both fired I think this would do what I need.

Can anyone give some pointers on what to try next? 

 

This group of code is basically what I'm trying to do
However when it gets to xpina<=xphaseA xphase B HAL debugger says Xphasea is not a pin

net xpina => parport.0.pin-02-out
net xpinb => parport.0.pin-04-out

net xphaseA <= stepgen.0.phase-A
net xphaseB <= stepgen.0.phase-B
net xphaseC <= stepgen.0.phase-C
net xphaseD <= stepgen.0.phase-D

net xpina <= xphaseA xphaseB
net xpinb <= xphaseA xphaseD

The pattern you listed is quadrature so setting the
step type to 2 (quadrature) and these connections
should be correct:

net xpina parport.0.pin-02-out <= stepgen.0.phase-A
net xpinb parport.0.pin-04-out <= stepgen.0.phase-B
 

This
Xphasea
is not the same as this
xphaseA
Linux, mind the caps.
The only thing i can see on the hal file that is not correct is stepgen type 5 for X axis but only 2 phases used, so that will not work or will work very harshly and with no torque.
For two phases, stepgen type 2 should work, as is the rest of your config, so do the rest work?

Thanks for the replies.

I only have one motor setup currently on a bench test rig so for all intents and purpose the other 3 don't exist.

I arrived at STEPGEN 5 because it was the smoothest in reverse.
If STEPGEN 2 is the correct output that matches the TURBOCNC parameters(which works well), that works for me. I just found myself second guessing the setup based on the STEPGEN diagrams not showing a "dead space" in signals. I believe the Motion Group box does some processing of the signal but I could be wrong on that.

Heres a video of the stepper running in Jog mode.




 

That looks more like motor miss wiring, is that a unipolar or bipolar motor and how many motor wires connect to driver/control box?

I believe the motors are 8 wire(to 4 pins)

 

rlkey=juwhpldi4pf5wihsfmique97f&dl=
unipolar.  www.pikpower.com/documents/SST83DSERIES.pdf

 


You can see here the turbocnc parameters that work. Pins being switched on a 2 and 4. So phase 1 hits both. Phase 2 hits pin 2. Phase 3 hits none. Phase 4 hits pin 4.
 

Please upload pictures here on the forum, your first dropbox link insist i register to view, the second gave me two warnings about cross site scripting attacks on my PC. I really do not like drops#it rummaging through my PC.
-
LinuxCNC can do stepgen types 5, 6, 7, 8, 9, and 10, all for 2 phase stepper motors, what you describe seems like type 8, not 5, so just edit the stepgen type, save and test.
From past experience, the most speed with good torque i got from 6 and 7, most torque from 10 but some stepper/drive combos really do not like it.
But, first, make sure the wiring is correct, no amount of software will help with a unipolar motor wired to a bipolar drive or vice versa.

If you only have 2 output pins, and  the drive is not step/dir
or CW/CCW, mode 2 is the only mode that makes sense...