thank you very much for this Dave I thought I had looked at everything on microchips site but I missed this. Appendix A is very helpful as for the transmitter device. also as I dont need the pressure sensing part or the LF part this will be a very small circuit which is great.
I am very greatful for this information, if you have some time and can assist on the receiving end (RXD) or the code as well that would be great.

Thanks again