04527247 is referenced by 81 patents and cites 91 patents.

An environmental control system for use in greenhouses or other structures requiring the control of a temperature regulating element in response to sensed temperatures. The environmental control system includes a plurality of sensor elements and actuator elements comprising peripheral control elements each of which communicate bidirectionally with individual communication interface units. A central control processor bidirectionally communicates with another communication interface unit. All of the interface units bidirectionally communicate with each other over fixed AC power lines by frequency shift keying the information onto and from the lines. The control processor receives operator inputs which cause it to assign time slots to different peripheral control elements to configure the system whereby each peripheral control element can be interrogated by addressing it during its time slot. In response to an interrogation, a sensor replies with data corresponding to a sensed parameter while an actuator replies with an acknowledgement and awaits control commands. A unique framing character is generated at the beginning of each time slot for alerting all peripheral elements that the next character generated will be an element address and for synchronizing multiple control processors to an identical time slot clock.

Title
Environmental control system
Application Number
288740
Publication Number
4527247
Application Date
June 19, 1984
Publication Date
July 2, 1985
Inventor
Theodore R Lapp
Mission Viejo
CA, US
Fredrick P Kaiser
Orange
CA, US
Agent
Fitch Even Tabin & Flannery
Assignee
IBG International
IL, US
IPC
H04Q 11/00
G06F 15/46
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