Disabling an optional 4th Axis on a CNC Router

[broered]

(Hoping this doesn't show my ignorance too much.)

I'm building a 3-axis CNC router.  The router will have a a 4th 'A' axis rotary device that will be used on occasion.  My configuration uses the PMDX-422 BOB, Driving Gekko G203V Stepper drivers through the PMDX-134 board.  From the PMDX-134 board I'll route the stepper motor wires to 4 panel mounted connectors - one for each of the 4 stepper motors.

When I'm not using the 'A' axis is it possible to just unplug it without causing harm to the electronics?

[Bob at PMDX]

While the G203V manual (http://www.geckodrive.com/g203v-rev-7) states that it will "will survive accidental motor disconnects while powered-up", we recommend that you remove power from the G203Vs before connecting or disconnecting a motor.  It is OK to have a G203V (or pretty much any stepper motor driver) powered on with no motor connected.

Bob