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:
Nov. 28, 1978
Filed:
Aug. 02, 1976
Clair R Grosso, Folsom, PA (US);
Richard M Gatti, Broomall, PA (US);
Robert J Miles, Hatboro, PA (US);
Raymond D DiSandro, Philadelphia, PA (US);
Other;
Abstract
A master station communicates with remote stations by respective transmit-receive pairs. Quadra-phase modulation is utilized, involving a carrier having two characteristic frequencies not present during bursts of a communicated signal, which bursts are known to last for a fixed duration. Signals on a receive pair are detected, and phase locked loops are tuned to the characteristic frequencies of the carrier and produce logical signals to indicate whether the characteristic frequencies are present. If not, a timer is energized to inhibit institution of a loopback condition for the duration of a data burst, after which the phase locked loops are permitted to enable the loopback.