Cause : Encoder 1 feedback fault.

If fault appears during first start-up before
encoder feedback is used:
- Check cable between encoder and
encoder interface module (FEN-xx) and
order of connector signal wires at both
ends of cable.
If fault appears after encoder feedback
has already been used or during drive :
- Check that encoder connection wiring
or encoder is not damaged.
- Check that encoder interface module
(FEN-xx) connection or module is not
damaged.
- Check earthings (when disturbances
are detected in communication between
encoder interface module and encoder).
For more information on encoders, see
parameter groups 90 Feedback
selection, 91 Encoder module settings,
92 Encoder 1 configuration and 93
Encoder 2 configuration.
Check the event log for an auxiliary code.
See appropriate actions for each code at
warning A7E1 Encoder 1