Set up using AMC AB15A100 drives, brushed DC motor Prototrak Plus with Encoders

There is something wonky going on, and I have no idea what it is.

Set the Amplitude to 0 in the Test.gui, and enable the drive and adjust pot4 so there is no drift. Once the neutral point for Pot4 is found you should not need to mess with it.

Is it possible you have some wiring fault some where that could be messing up the analog command from the 7i77 to the drive, or some problem with the encoder wiring? If there were an intermittent problem with the drive reading the encoder signal when moving in the one direction, I could see that being the result.

It might be worth while hooking up the real o-scope to the encoder wires. Use 2 channels, one hooked to the A, A/ and the other to B, B/ (unless they are single ended then it would be A, ground and B, ground). Make sure both channels are nice clean square waves 90deg. offset to each other.

If the encoders are differential signals, it might even be advantageous to look at the encoder signal using all 4 channels of your scope, with each encoder wire connected to a channel and to ground. Then you should see A and A/ as opposite square waves, same with the B and B/.

Todd, Thank you. This morning, I have adjusted Pot 4, as per your suggestion, the only change in "test" screen was the 0.0 for Amplitude, there is an area "nearly a full turn on Pot 4 was that area where the axes would slow but not change direction, the nearly full turn was like "lost motion", you go past the "sweet spot" & need to back up some. I set it at mid-point between the 2 end points of where it would change direction.

The encoders are single ended, so I will be attaching o-scope with short temps at TB3. The encoder is US Digital # EM1-2-500-N, this is link: www.usdigital.com/products/encoders/incr...s/em1/em1-datasheet/
When o-scope is connected I will only us 2 channels, because they are single ended.

I am to do a visual inspection looking for broken wires and the like? Can I swap motors to tease out where to start to look?

Many thanks!

Todd, Many thanks!! I believe that the o-scope is connected proper, but have not mastered the o-scope settings. This attached pic, is this the type of trace I am to look for or adjust scope to? Not completely shore of what to expect in the trace.

Many thanks

tommylight, many thanks for your help. I need to be transparent the "test" screen was set to 0.15 Hz & 0.45 Volts & Offset =0. Do these settings seem correct to you? Or is the "0" you reference to the o-scope setting or "test" screen?

Many thanks.

I'm not so sure the signal is all that noisy in that image. The scope setting is layering many many sweeps for the same trigger point, on channel one. And you are seeing multiple rises on channel 2 layered over top of each other and those are not all in the same position because of variation in the velocity. Try pressing the "Single" button to get a single trace sweep.

You'll want to zoom out on those waves so that you can see a larger number of cycles to look for noise. And you'll want to examine and compare what the pattern looks like while the machine is moving in each direction, since before it was only looking goofy when moving one way.

Todd & tommylight many thanks! I tried the o-scope a few different ways using the "single" and this is the trace. I used the "intensity" to clear up the screen. Is this better? The base line is aligned (zero is same for both) for both channel.

Many thanks!
 

Many thanks! This is a trace zoomed out, today I do not notice in the trace any difference (as table moves one direction vs. than other) in the directions, I tried the HAL Scope with setting (as ended yesterday; sw2=1.147, pot1=10.0,pot3-6.75. Only change was Pot4. Today set pot4 as per Todd's post (01 Sep 2022 20:45) was how Pot4 was adjusted.

Edit: Do you think that having the Rigol o-scope connected that it may make a difference when tuning the HAL o-scope?

Many thanks!