Unfortunately I havent gotten that far through the manual yet! There are a few encoders on ebay at the moment so I might try to get one of them and have a go.
I have managed to get a few more hours on my build over the last few nights and I nearly have the control panel finished. I have decided to wire my limit switches through relays supplied at 24VDC and just switch the 5vdc from the BOB. I have them to fit and connect up then it will be ready for a first power up.

Ian