Cause : Cause 1: Communication between drive and option module (FEN-xx and/or FIO- xx) is lost.

Cause 2: Speed feedback (19.02 Speed fb sel) has been selected from an encoder which does not supply speed feedback.

SSI and EnDat type absolute encoders do not supply speed feedback in Continuous mode (91.25 SSI mode and 91.30 Endat mode)

Cause 1: Check that the option modules are properly connected to slot 1 and slot 2.

Check that option modules and slot 1/2 connectors are not damaged.

To determine damages in the modules and connectors, test each module individually in slot 1 and slot 2.

Cause 2: Use the estimated speed value or select another encoder mode.

Check parameters 19.02 Speed fb sel and 91.25 SSI mode/91.30 Endat mode