Whiteriver,
I have been following your thread hoping for an answer also. First off, I am not practiced or knowledgeable in the use of a scope so I am suggesting from a blind aspect!
I went back and looked at an older version of the manual I have for the 320 and after having read it over the years several times, I finally "think" I may have a possible answer for both of us.
From the manual:
"To see how your servo is compensated it is first necessary to induce a disturbance. The easiest way is to switch the
DIRECTION input while commanding a constant speed via the STEP input. The abrupt direction change puts just the
momentary load needed on the motor while you watch how it responds.
If you are using an oscilloscope, use channel 1 on the test point and channel 2 on the DIRECTION input. Set the trigger to“normal” , trigger source to channel 2 and trigger edge to “+”. You should see a single sweep for every clockwise changein direction.
Slowly increase STEP speed until you get a picture similar to one of the three above, and then do the following:"
From this, I think we need to have a signal generator to put on the step line to generate a constant series of pulses (constant feed rate) AND then an electronic toggle switch on the direction line. I think this will trigger the sweep needed to generate the desired trace on the scope??? This could be done with a couple of 555 timing chips if necessary!
I wish someone who is knowledgeable would jump in and confirm or set me straight!
Art
AKA Country Bubba (Older Than Dirt)