Abstract: A data sharing mechanism employs a broadcast bus communication system to physically interconnect various control and monitoring nodes that cooperate in controlling a physical process. Shared, or global, variables are exchanged between connected nodes via a global data service provider and protocol. The protocol allows global variables to be addressed by symbolic names with multiple namespaces for the names. Additionally, the protocol allows data to be formatted with special identifiers such that once a variable name has been located in a message from a specified source, and other messages from that source with the same identifier are received, they will have the named variables in the same relative locations. The receiver can therefore directly index to the named variable when the source and identifier are known.