You must be getting pretty sick of me now Hood... But here is the latest:
I have been playing around with Enable1 under the Output signals.
Setting the pin to 1 means when i press the spindle start button, the F value increases on the VFD (Spindle off ~70, Spindle On ~ 350)
Setting the pin to 17 gives the same Run sign illumination for the briefest of instants when Spindle start is pressed (only to start not to stop)
Setting the pin to 14 has no visible effect.
This was done with the Step and Dir Pins in Motor Outputs set to 0