Dear Andrew,

Thanks for that short tutorial.

Have been reading quite a lot on this PDO and SDO and now CANopen is no longer an intimidating thing. Yes the CAN itself is very simple and its the higher layer protocols which have been designed to be more universal that make it look complex. There again I will need to use a very few sub set of functionality.

Possibly next week the hardware should come in and I should be using CANopen, much to the relief ......of my client !

Raghu