I've ordered the Planet-CNC Output Control board, in order to generate the 0-10V signal to control the speed of the lathe spindle, but the Mitsubishi inverter which is fitted to this lathe uses two separate signals to control the direction.

From the Mitsubishi manual:

STF - Forward start input signal - Motor starts rotating in forward direction when STF and P24 are short circuited. Stops when opened.

STR - Reverse start input signal - Motor starts rotating in reverse direction when STR and P29 are short-circuited. Stops when opened.

There are relays for this purpose on the driver card already, but I presume I need to generate two separate outputs from which ever Mk2/4 output pin I designate for the purpose of spindle direction ?

The lathe needs to rotate in both directions as the turret holds the cutting tools behind the work piece, so turning etc happens in reverse, but drill bits require the spindle to rotate in the forward direction as per a normal lathe.

I guess I could just buy a good range of left handed drills ...

Adrian.