That's right Swarfing.
The Orac's controller decides what resistance value to apply at the inverter input. And is wired directly to it even though the VFD may be removed and operate as stand alone to control motors of some other system.
Even when the machine is at manual mode the controller does the accel/deccel i guess by digitally switching resistors internally. It has to be this way how else would it be!
Is that the question or I have missed something due to the foreign language factor which applies for me here.