Coordinated Motion - 2 servos / 2 axes / 1 belt

You can find the extended error codes in the instruction help by right-clicking the MCT instruction. Looking at the list the error you're getting reads "Set the transform dimension of the source system to the number of axes in the system, up to three."

I would guess that you will similarly get an EXERR 4 once you fix that as you will need to do the same for your second MCT for the real axes.

Clatchet said:

You can find the extended error codes in the instruction help by right-clicking the MCT instruction. Looking at the list the error you're getting reads "Set the transform dimension of the source system to the number of axes in the system, up to three."

I would guess that you will similarly get an EXERR 4 once you fix that as you will need to do the same for your second MCT for the real axes.

Click to expand...

Interesting. I didn't expect to see them at the bottom of that page. I went right to the linked "error codes" and "extended error codes" pages. Thanks.

We found this on YouTube. It shows what is happening much better.
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This is an interesting problem but it shouldn't be that hard to translate X and y positions to motor revolutions, counts or even distance. I think it would be easiest to scale the motors so they work in distance units on inches. This cleans up a lot of the math or coefficients you see above.

Thanks to the references you provided, this worked out pretty well. Very easy to program.

One odd question as I don't ever recall encountering this with motion. Last night before I left, I did an upload of the PLC program, and saved. Then turned the servos off and powered off the PLC. Arriving this morning, I downloaded the new program and noticed that the position values were completely different than prior to downloading. Why? The servos didn't move and I had uploaded before saving.

Are you using incremental encoder or absolute encoders, with incremental encoders they do not remember there position so I think they just come up with a random number when powered up, whereas absolute encoders will remember there position when powered back up.

alan_505 said:

Are you using incremental encoder or absolute encoders, with incremental encoders they do not remember there position so I think they just come up with a random number when powered up, whereas absolute encoders will remember there position when powered back up.

Click to expand...

They're absolute. Powering up is fine, but after the download, the positions changed. In other words, I have to home every time I do a download.

Are you saving and then redownloading the values that you saved without moving any axes?

alan_505 said:

Are you saving and then redownloading the values that you saved without moving any axes?

Click to expand...

Yes, but I believe this is actually a hardware issue after what I experienced yesterday afternoon. Last thing I wanted to do before I left was power-down, power-up, and make sure all the cycles ran properly. The controller took a very long time to reboot, but when it did come up, it had no program. I already had the SD card removed, so it wasn't faulting on that. Therefore, no point in trying to figure this out why the controller is exhibiting odd behavior. AB says we should have a replacement by Monday, so we shall see.