04742475 is referenced by 107 patents and cites 95 patents.

An environmental control system for use in a greenhouse or another structure which requires the control of an ambient condition regulating element in response to a plurality of sensed parameters. The system includes a plurality of sensor elements and actuator elements, which communicate with a central control through communication interface units. In an illustrated embodiment the interface units communicate over previously installed AC power lines by frequency shift keyed signals. The interface units communicate to the peripheral control elements and the central control unit through serial digital signals. The central control maintains a protocol where, in response to operator inputs, time slots are assigned to different peripheral control elements to configure the system. Each peripheral control element is thereby addressed during its time slot and a sensor responds with data corresponding to a sensed parameter and an actuator executes a command. A unique framing character is generated by the central control at the beginning of each assigned time slot for alerting the peripheral control elements an address will next be generated and for synchronizing multiple central controls to a common time slot clock.

Title
Environmental control system
Application Number
288740
Publication Number
4742475
Application Date
September 26, 1984
Publication Date
May 3, 1988
Inventor
Theodore R Lapp
Mission Viejo
CA, US
Frederick P Kaiser
Orange
CA, US
Agent
Fitch Even Tabin & Flannery
Assignee
IBG International
IL, US
IPC
F24F 7/00
G06F 13/12
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