Intermittent differential encoder error on x axis only (Resolved)

[Chas]

There i was thinking everything was ready to go and hey, another issue pops up. I thought i'd try the lathe out initially in manual mode using my newly operational handwheels. Everything works fine for about 5 minutes or so and then everything shuts down with an X axis differential encoder error message. if i switch everything off for a few minutes and rehome then try again everything is fine again for a few minutes then it all trips out again with the same message. Does this sound like a dodgy encoder on the x axis motor or is there something else i should try. Report attached.
Many thanks.

[cnckeith]

Hi Chas,
please tell us more about the axis motors being employed.

[cncsnw]

Does this sound like a dodgy encoder on the x axis motor

Isn't this the system with Mitsubishi servo drives?

If so, then the encoder signal at issue is not the one between the motor/encoder and the drive; it is the one between the drive and the Oak.

[Chas]

Hi, yes this is the Mitsubishi mr-j2s system. It seems to be okay for a few minutes then the fault occurs which is why I’m very confused . It’s almost as if once it’s warmed up the signal requirements are no longer met ,but only on the x axis , I’ve had no issues yet with Z but as I say I haven’t been able to run for more than 5 minutes or so. If it was a noise issue surely the error would be constant. I’m at a loss I’m afraid.

[cncsnw]

Can you swap Oak interface cables between X and Z?

Swap both ends, so X is still X and Z is still Z, but each axis is using the other's cable.

For testing, you could set Machine Parameter 332 = 2, but that is risky. On the one hand, it would let you see whether the failure is partial and fleeting, or complete and persistent. On the other hand, setting P332 = 2 might allow a full-power axis runaway to continue for a considerable distance (typically several inches) if the encoder signal fails.

Just try swapping the interface cables first, if possible.

[Chas]

Hi , swapped the interface cables over as suggested and it has run with no hiccups all morning. I can only think that there was a dodgy connection somewhere and swapping them over has corrected this. It’s possible it may happen again but at least I have a better idea of where to look.
Many thanks as always.