icepap: OFF state != POWEROFF
(reported by @muzelle)
For Axis
, currently "OFF" state corresponds to "DISABLED". For icepap in particular, there is a "POWEROFF" state.
It would be better to have a new standard state called "DISABLED" for disabled motors (whatever that means), and
to use "OFF" when motor power is switched off ; indeed, "ON" is set when motor power is on...