Distributed environmental/load control system

Claim 1

A distributed environmental/load control system comprising: a thermostat including a sensor for sensing a parameter in an environmentally controlled space and adapted to produce signals indicative of the sensed and desired values of the parameter; a firt controller adapted to control condition changing equipment for regulating the parameter in the environmentally controlled space in response to command signals; a communications link between said thermostat and said first controller for supplying the signals produced by said thermostat to said first controller as the command signals; a second controller adapted to control loads connected thereto in accordance with predetermined criteria to limit energy consumed by the loads; a computer apparatus adapted to communicate with said second controller and having a first input terminal for receiving signals which may be processed in accordance with instructions from said second controller, an output terminal for supplying the processed signals, and a switching terminal for supplying a switching signal if the signals received at the input first terminal are to be processed; a first signal coupler for coupling the signal produced by said thermostat to the input terminal of said computer apparatus; a first switch in said communications link and controlled by the switching signal for breaking said communications link between said thermostat and said first controller in the event the signal produced by said thermostat is to be processed; and means for connecting the output terminal of said computer apparatus to said communications link on the side of said switch connected to said first controller for supplying the processed signals thereto, whereby said computer apparatus is operable to process the signals produced by said thermostat in response to instructions furnished by said second controller and to supply the processed signals to said first controller as the command signals.