1756-M02AS Fault

I've got a 1756-M02AS card installed, along with the SSI encoder. I was able to get the Axis to tune, but after I couldn't get it to run a MAJ or MAM command. The fault code came up for PosSoftOverTravel, yet I don't have the soft limits enabled yet?

Anyone else seen this?

I'm running V 15.00.00

Any ideas? To say I'm frustrated would be an understatement.

Even 32 bit position can overflow

Are you trying to do a rotary application with the M02AS configured for a linear one? If your M02AS is configured for linear mode I don't think the counts per turn is subtracted from the position so eventually the position will overflow 32 bits.

I will be able to provide more info later when I am home.

I'm doing a linear application. The encoder has 4096 positions per turn, and 4096 positions. I don't believe I've overflowed, but I'll check.

Thanks.

OK. I set the Axis to feedback only, and reset the encoder by applying +24 V on pin 9 with the Axis beyond the negative limit switch.

Moved the Axis manually back into position, and it tracks the position nicely. Went all the way to the far limit, no problems with the feedback.

I set the Axis back to servo mode, set the auto tune, and it gave me some values back. Using the motion direct commands, I cleared all faults, turned on the Axis, and ran a MAJ (motion jog). Ran into the same problem, Positive Overtravel.

Now I'm writing this & going to get a 64 oz. caffine shot before I stare blankly at it again.

OK. Figured it out.
Just in case anyone runs into a similiar problem, or runs a search on the 1756-M02AS card or 842-31GB encoder, I'll give a brief description.

I ran the SSI cables along a festoon, with 480 VAC Power Cables next to it. I know, but it's the only way to get the parts up there.

Pin 9 drives a reset on the SSI encoder, when connected to +24 Vdc. I would up grounding the Pin 9, and viola, problem goes away.