LogNet: a low cost, high reliability network for embedded systems

摘要

A low cost network efficiently supporting both event-driven and constant data rate messages is implemented using inexpensive off-the-shelf micro controllers and firmware. The network firmware uses less than 2K bytes for the network hub and less than 1K bytes for the other network nodes A combination of polling and token passing ensures each node can become "Master" and control the network and thus providing for steady data rate transfers. A specially designated "Hub-node" ensures fairness by preventing idling nodes from unnecessarily taking control of the network access. The Hub controls the token advance signal going to all nodes. The client/server protocol with peer/peer capabilities utilizes both master/slave and token passing media access methods.