Some Manufacturers have an external power enable circuit to their SERCOS drives to enable power. This prevents the Cyclical Interrupt from being installed, which traps the SERCOS state machine in a place where it does not do its normal processing.

In this state, I have added checking to allow drive settings to be modified and drive errors to be cleared. The drive status is also modified to indicate the drive is not ready and is waiting for Cyclical Data to be enabled.