Thanks for the response bud - yup I tried all that a couple of times before.
For some reason its now working!! - Last couple of times I tried it, I couldn't seem to get it to respond (it didn't even show RPM)
I've just done it again now - and for some reason after fiddling with a couple of settings (minimum and max settings) it started to work.
Guess it just needed a bit of patience - hmmmm
Hope it stays working as I've had this before with a previous Liang DDC - sometimes it would show RPM sometimes it wouldn't....