[sonu]

DMF 250L
a) X-axis tries to run without any command,when release emergency and push power ON button.
b) U-axis also behave like this.

Can some body plz help in resolving this fault.

[Bdrangdo]

There could be various reasons for this, have the "U" axis and "X" axis cables been interchanged, the most likely reason is that there is no feedback from either the resolver/encoder or in the case of DC drives the tacho signal is missing or wired.
wrong. It is odd that both axis's are affected. Usually Heidenhain's will show an error if the feedback signal is missing, also it should shut down the servos once the following error has been exceeded. You need to check the wiring and connectors first. Try disconnecting the power to the affected servo's and then turn the screws by hand and watch the DRO in jog mode to see if the feedback signals are being sent and interpreted correctly.

[sonu]

Thanks Bdrangdo for the reply. I will check the things as you suggested,