Problem- Relative & Absolute position displays stop updating??

[dcoupar]

I ran into a strange one the other day at a customer with a VMC (Fanuc 21iM).

After power up, he handwheeled X, Y and Z close to the fixture and started the spindle to use an edgefinder. At this point all was well.

He then moved Z down and X over. At some point, he noticed the Relative and Absolute position displays were not changing along with the Machine position!!!

I paid a visit to the customer site and witnessed this myself.

Has anyone seen this before?

[stevo1]

Dave…I have seen this before a long time ago on a 15t control. IIRC there was a switch/pushbutton on the control that had been depressed by accident that is normally off but I do not recall exactly what it was called. It was not the machine lock switch but I want to say something like “AUX” or another. I will try and see if I can dig up some old photos of that control and try to make out the switches name.

Stevo

[fanuc-support.c]

I had this, along with one row of keys not working on a 21-TA. It was the graphics in this instance. Very intermittant with the display and pretty much a solid fault with the keys. And of course, the graphics card was the last thing i changed in the control. Doh..

[Ozemale6t9]

Sounds to me as if manual absolute was switched on. On some machines this allows manual repositioning of the machine without the position being updated. Only machine coordinates update.

regards, Oz

[dcoupar]

Originally Posted by Ozemale6t9 Sounds to me as if manual absolute was switched on. On some machines this allows manual repositioning of the machine without the position being updated. Only machine coordinates update. regards, Oz

Well, I guess we can watch the diagnostics to see if Manual Absolute is somehow switching on. Thanks for the idea.