Multiple value multiple owner message class

An environmental control network with a network bus, the network comprising:

• at least one environmental condition sensing device connected to the network bus, the sensing device including:
• a transmitter for transmitting messages over the network including at least a demand value;
• means for monitoring the network bus at the sensing device for any messages sent from other sensing devices that may be present on the network;
• and
• means for terminating further transmission of the message from the producer device if the producer device senses a message from another producer device with a greater demand value;
• at least one consumer device connected to the network bus, the consumer device including means for responding to a demand value last received over the network bus.

A method of communication between at least one producer device and at least one consumer device in an environmental control network, comprising the steps of:

• transmitting a message from the producer device on the network for receipt by the consuming device and other producing devices that may be present on the network, the message including at least a demand value;
• monitoring the network at the producer device for any messages sent from other producer devices that may be present on the network;
• terminating further transmission of the message from the producer device if the producer devices senses a message from another producer device with a greater demand value;
• monitoring at the producer device the time interval from transmission of the last message on the network for receipt by the consumer device, and initiating transmission of messages from the producer device to the consumer device when the time interval exceeds a predetermined value;
• and
• the consumer device responding to a demand value last received over the network and intended for receipt by the consumer device.