Cnc with Siemens 802d forgets job position

mohnish · Feb 26, 2019

My Cnc with Siemens 802d forgets job position when switched on in the morning and dashes into the job 5mm in the z axis direction. Then the machine runs smoothly afterwards. I have an absolute encoder. Mechanical problems are ruled out. No error comes. What could be the problem?

ChrisPollack · Feb 26, 2019

the 808 control uses a capacitor for its flash memory. if the capacitor is off tool long then the system will boot up from a previous backup. this could explain your positioning issue. before powering off your control go to System and select the Save Data soft key. this will create a hard backup that the system will reload automatically on power-up if it detects a power loss. hope this helps.

mohnish · Feb 27, 2019

Nope that doesent help. Same problem. Could the encoder be faulty. Or the software needs to be refreshed

gustafson · Feb 27, 2019

I recently replaced an absolute encoder in a heidenhain controlled machine and while the symptoms were very different, it is possible that would make sense. The key was that the absolute section of the encoder is only used on startup, and the incremental takes it from there.

So the result is that it starts in the wrong position, but otherwise runs normally

qrovin · Feb 28, 2019

machines need batteries replaced every so often also . Our doosan usesdsize and dmg uses aa batteries .
Have you replaced yours lately?

Search

Largest Manufacturing Technology Community on the Web

Search

Cnc with Siemens 802d forgets job position

mohnish

Plastic

ChrisPollack

Plastic

mohnish

Plastic

gustafson

Diamond

qrovin

Aluminum

Similar threads