KSN

Hello.
If encoder is parametrized for using in the drive and you disconnect the cable during run you will get the F048.
What are you using as actual speed value? What value have the parameters P083, P626. Check the fault value in parameter r047.001 when you receive your faults.
Change between I and II means that the torque direction changes from positive to negative.

Goran_

P083 is freely wired. P626 is k167. If I disconnect the encoder from x400, where is connected encoder from the motor that the drive powers, I get F042. Disconnecting the encoder from another motor gives F048.

R047.001 is 2. So is change of torque connected to this fault.F048, because other two drives are always displaying I.

KSN

You mean P083=4? Then what the value has the parameter P609?
r047.001=2 means that the encoder is defective, read about this in description of F048 in the manual.

Goran_

Where did you read that its says encoder is defective when r047.001=2? I have not found this information in the manual "Simoreg DC-Master oparationg instructions for 6RA70 Series".

F048 says its either encoder or cable. I have replaced the encoder with new one and same fault. Is it 100% that the error comes from encoder connection? ANd also, how do I know which encoder does it reffer to? I am suspecting encoder from "external" motor, but how can I be sure?