Yeah, I did see that Alex and did put my VIN number into VIDA and hit the READ VEHICLE button but still got a communication error.
What I hadn't noticed (or it only happened after I disconnected thee battery) was that the DIAGNOSTIC tab had become "live". It was only after clicking on this DIAGNOSTIC tab that I got it to all work together and read the DTCs.
Anyway, thanks for the help, I'm probably just too dim to work it out first time!!