canopen sdo advanced

It should be noted that the default scheme used for assigning the message identifiers only allows one client to be on the network. Because message IDs must be unique, no two devices have the right to send SDO requests to the same node at the same time.

The entire SDO communication was designed around the idea that only one node in the system needs the power to access each and every Object Dictionary entry in each and every node. This is either a configuration tool or some sort of master responsible
for configuration.

Where required, CANopen optionally allows the implementation of 
1. a method to perform SDO channel sharing 
2. a method that provides additional SDO channels. 

1. the clients implement a method of sharing the existing channels. 
   This is implemented via a so called SDO Manager that is responsible for all SDO channels and by default is the only client that may use any of the channels. Other clients that w