Right thanks for all the help Dean.

In answer to the questions:

Yes DAC turned on in plugin.

Did continuity test, get nothing between pins when they are on or off.

Have just wired up a din relay to output 1 from the csmio and got it working first time no problem. So who knows but I'm happy with that

The only thing that's not working quite right is the rpm if i set it at 2000 or 1000 it spins the same speed. Analog signal is fluctuating as expected with the different s commands so I think I've probably not set something right on the inverter parameters?