I am re-wiring my machine to it's (semi)final configuration. During this I am adding a charge pump and spindle control from Cnc4Pc.

The wiring diagram for the charge pump:

http://cnc4pc.com/Tech_Docs/C4R5_WG.pdf

shows an external enable switch as well as an E-Stop.

Is this external pushbutton enable switch really necessary and can I just wire it out of the circuit?

Thanks,
BobL.