Abstract: Communications methods and apparatus are disclosed for multiple subsystem intercommunication for supervisory and control systems such as can be found in heating, air conditioning, energy control and other environmental control equipment that are installed in buildings and the like. The present invention provides an improved system which includes improved distribution means wherein data from individual distribution panels is discriminantly transmitted to the host computer as a function of the present sampled data and the data previously transmitted, preferably wherein the present rate of data transmission to the host computer is determined as a function of the previous rate of transmission.The present invention provides distribution means wherein the characterization or definition of the specific function operations that are to be performed by individual control point apparatus can be carried out by instructions that are provided by an operator from a central or host computer.

Abstract: An improved distribution system for use in supervising and controlling temperature and other environmental conditioning equipment of a building or the like is disclosed. The distribution system is used in conjunction with a host or central computer. The distribution system includes one or more distribution panels which communicate with the host computer as well as with various control point apparatus that gather temperature, humidity, and other types of values, or gather status information regarding electrical switch states and the like. Other types of control point apparatus control electric motor starters, motors, or other control equipment for controlling environmental conditions or general energy use. The distribution panels have various function means therein which are capable of receiving digital input signals, providing digital output signals to control point apparatus, receiving frequency analog input signals, pneumatic analog input and output signals, and the like.