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:
Dec. 23, 1997
Filed:
Dec. 16, 1994
Raymond Lippmann, Ann Arbor, MI (US);
Michael John Schnars, Clarkston, MI (US);
James Edward Nelson, North Branch, MI (US);
James Robert Chintyan, Davison, MI (US);
Delco Electronics Corporation, Kokomo, IN (US);
Abstract
Two or more communication modules are coupled by a one wire transmission line. A feed module impresses dc power and a sine wave carrier signal on the line. Each module generates a square wave signal synchronous with the carrier, each period of the signal representing one data bit. Data is written onto the line by a module by attenuating the carrier wave for selected bits and read by another module by sampling the bits and detecting those which are attenuated. Address and message data is transmitted in packets of n bits, the first bit always being an attenuated bit. Addressing is accomplished by generating a sequence of n unattenuated bits and then writing packets of address data. An address is valid when it matches a stored address in a module and that module is then activated to read or write. Multiple addressing modules can be used with a priority technique which reserves a priority code location at the beginning of an address string and compares code bits of a sending module with carrier bits, and aborts the address write when the carrier has an attenuated priority bit and the sending module is attempting to send an unattenuated bit.