Supervisory and control system for environmental conditioning equipment

A system for supervising and controlling equipment used to control the environmental conditions in a building or the like, comprising:

• a control console at which an operator can observe the operation of the environmental control equipment from data received from remote field points connected in said system;
• one or more multiplexing modules connected to one another and to said control console in a single leg circuit, each of said multiplexing modules sequentially addressing the remote field points connected thereto by selectively transmitting unique address signals to all of the field points connected thereto and receiving identification and status signals from the addressed field points, and multiplexing modules selectively issuing command signals for operating and adjusting control equipment associated with a field point;
• each of said field points comprising a field point module and one of various types of field point units, said field point modules receiving all of said address signals from the multiplexing module to which it is connected, each field point module identifying its unique address signals, each field point module transmitting field point module identification signals and status information signals from an associated field point unit in response to receiving its address signal, said addressed field point module receiving command signals from said multiplexing module and forwarding the same to the associated field point units;
• said field point units producing electrical signals that are indicative of a measurement or condition, certain of said field point units implementing received command signals for effecting a control equipment adjustment or the like;
• said field point modules associated with one of said multiplexing module being connected to one other and to said multiplexing module in a leg circuit.