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:
Apr. 26, 1977
Filed:
Nov. 10, 1975
John M Holland, Shawsville, VA (US);
American District Telegraph Company, New York, NY (US);
Abstract
A radio central station alarm system including a central station and a plurality of remote stations for transmitting alarm signals to the central station by means of radio signals. Alarm signals are transmitted repeatedly in a sequence which reduces the probability that signals transmitted by one remote station will be completely obscured by signals transmitted by other remote stations. A pulse position modulation binary data format is used which simplifies both remote and central station apparatus and facilitates error-free data transmission. The central station is highly immune to noise and performs a number of tests on received data signals to reduce or eliminate false or erroneous alarm indications. Latching alarm sensor circuits are provided for use at the remote stations to insure that all transmission sequences are completed. Protective circuits are provided for disabling any remote station which transmits signals for longer than a maximum allowable transmission interval.