OK. Just connected up the 24v from the inverter to the 12-24v input on the BOB and punching in a speed on the SDRO makes the inverter run. However, at 100% it's only giving 89hz instead of 100hz and it goes up slightly if I touch the 10v output with a screwdriver or meter probe - wierd. I'm getting around 9v across 10v and gnd.

Maybe I need to use a separate 12-24v supply to the BOB.