Distributed environmental process control system

In a computer network for real-time control of environmental control devices, the computer network including

• a plurality of nodes, each node connected for communication through a backbone network using time division multiplexing;
• a branch network, connected to a corresponding node;
• and
• a plurality of environmental controls connected to the branch network for communication with corresponding node;
• the improvement comprising:
• the time division multiplexing by which the plurality of nodes communicate includes at least one time slot during which no communications occur between nodes;
• and
• the plurality of environmental controls communicate through the branch network with the corresponding node during the at least one time slot.

In a computer network for real-time control of environmental control devices, the computer network including

• a plurality of nodes, each node connected for communication through a backbone network using time division multiplexing;
• a branch network, connected to a corresponding node;
• and
• a plurality of environmental controls connected to the branch network for communication with corresponding node;
• the improvement comprising:
• the time division multiplexing by which the plurality of nodes communicate includes at least one time slot during which no communications occur between nodes;
• and
• the plurality of environmental controls communicate through the branch network with the corresponding node during the at least one time slot, wherein communication over the backbone network is performed using a synchronous peer-to-peer protocol, further comprising a synchronizing node having an output carrying a synchronization signal, the output connected to the backbone network,
• a first one of the plurality of nodes having an output carrying a replacement synchronization signal when the synchronization signal fails to reach the first node within a predetermined period of time.

In a computer network for real-time control of environmental control devices, the computer network including

• a plurality of nodes, each node connected for communication through a backbone network using time division multiplexing;
• a branch network, connected to a corresponding node;
• and
• a plurality of environmental controls connected to the branch network for communication with corresponding node;
• the improvement comprising:
• the time division multiplexing by which the plurality of nodes communicate includes at least one time slot during which no communications occur between nodes;
• and
• the plurality of environmental controls communicate through the branch network with the corresponding node during the at least one time slot, wherein:
• one of the nodes generates a synchronization signal and the synchronization signal triggers deterministic responses by the plurality of environmental controls, wherein said deterministic responses include a plurality of control data for each environmental control and wherein the one of the nodes maintains a summed tally of at least one of the control data.