The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 17, 1989
Filed:
Mar. 14, 1986
Mervin L Grindahl, Waseca, MN (US);
Quentin S Denzene, Waseca, MN (US);
EnScan, Inc., Minneapolis, MN (US);
Abstract
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.