04799059 is referenced by 243 patents and cites 33 patents.

An improved automatic/remote RF instrument monitoring system including a plurality of transponders configured to operate with one of a plurality of parameter sensing instruments remotely located from an interrogate/receiver. The interrogate/receiver transmits RF transponder activation signals in the form of a tone modulated onto a carrier. In response to the activation signals, the transponders "wake-up" and transmit an RF transponder signal which is received and processed by the interrogate/receiver. The transponders include a transmission enable circuit which initiates transmission of the RF transponder signals at random times after receipt of the activation signals. The RF transponder signals are formed by a plurality of spaced transponder information packets. Transponder information packets of the transponder signal are transmitted at pseudorandom frequencies as a Manchester encoded bit stream including a preamble field of predetermined preamble data, an instrument parameter field of data sensed by the instrument, an instrument identification field of instrument identification data, and an error control code field of BCH error control code data.

Title
Automatic/remote RF instrument monitoring system
Application Number
6/839889
Publication Number
4799059
Application Date
March 14, 1986
Publication Date
January 17, 1989
Inventor
Quentin S Denzene
Waseca
MN, US
Mervin L Grindahl
Waseca
MN, US
Agent
Kinney & Lange
Assignee
EnScan
MN, US
IPC
G08C 17/00
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