Cause : Mld Tachof comes when the rotating measurement has detected a fault in the speed actual value signal. The fault value defines the type of fault.

The fault measurement may have been erroneously generated if the drive speed is externally forced (e.g. completely locked drive generates the "no signal" message).

1. Check the measuring cables.
2. Check the parameters - P208 S. speed act. val. & P209 encoder pulse no.