G320 Locks & Sings, but NO Step

[mikkojay]

Hello,
I have connected a new g320 to my servo/encoder, and I am having
difficulty getting it to step when sent motion controls from Mach2
running on my PC. I have previously used the Mach2 and my LPT1
breakout board to successfully control stepper motors (using a
compumotor stepper drive), so I do not believe that aspect of the
setup is suspect. I have completed the encoder test at the beginning
of the installation notes document, and from what I can tell, it is
doing exactly what it should. I hooked a voltmeter up to the test
points, reset the drive, and watched the voltage go up and down as I
slightly rotate the motor shaft back and forth. If I exceed 125
counts from center in either direction, a fault occurs exactly as I
would expect it to per the documentation.
Also, I would guess that using the encoder I am using (Heidenhain
linear), the number of degrees of motor shaft rotation from center to
fault light was about 2.

Next, I hook the motor up and reset the drive.
The motor chirp/hum/sings/vibrates and the shaft is locked.
If I apply torque to the motor shaft, I can feel the motor fight back.
I have no experience with servos, but I would think this is all normal
so far right?

Next, I open Mach2 and open the Motor Tuning window. I use the
up/down arrows to generate pulse and direction signals on pins 2 & 3
of LPT1 for the X axis. The servomotor just sits there and hums.
I also tried going into the pin output config and trying to change
from active hi to active lo as an experiment, but it still does nothing.

I know that the breakout board for LPT1 is supplying a full 5 volts
for the logic signals- I can watch the pulses on my o-scope. Also,
again, this output piped into a stepper motor drive works fine.

Any ideas would be appreciated. I can take pictures of my setup if
that would help.

The motor I am using is a MCG 2243-ME2919 rated at 80vdc max.
The Encoder is a Heidenhain LS143, using its own external p/s. The encoder p/s port is jumpered with a 470 ohm resistor per the instruction manual.
I am using a compumotor power supply that is currently configured to supply 35 VDC.



Thanks, Mike

[mikkojay]

It's alive!
I was so close-
This thread helped to point me in the right direction:
http://www.cnczone.com/forums/showthread.php?t=14064

It turned out that I was not sending +5v to the common anode side of the optocoupler terminal 12. It has the slide moving back and forth nicely- now I can get back to designing a machine!
Thanks, Mike

[mikkojay]

This is worth mentioning- Mariss from Gecko emailed me a reply within one hour (on a Saturday no less).
His email contained a spot-on solution to the problem.
Pretty cool.
Thanks, Mike