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:
Aug. 25, 1992
Filed:
Apr. 19, 1990
Stanley L Fickes, San Jose, CA (US);
Bernard E Stewart, Campbell, CA (US);
Robert J Grady, Windsor, CA (US);
Rick L Reagan, Santa Clara, CA (US);
John Piccone, San Jose, CA (US);
Richard C Allen, Los Gatos, CA (US);
Photonics Corporation, Campbell, CA (US);
Abstract
An infrared RS 232 communication link protocol is particularly suited for correcting any errors introduced during a transmission of information. The information is transmitted from a transmitting station to a receiving station. Each of the stations has a control counter each of which toggles between a logic 0 and 1. The control counter for the transmitter and the receiver are phase locked so that all errors may be corrected. The receiver echoes each data bit back to the transmitter which compares the echoed data to the transmitted data. If there is a match, the transmission was successful. If there is no match, the data must be retransmitted. A retransmit control character RTXx is sent to indicate that the receiver should discard the previous character and prepare for a retransmission of the character having the error. Under the proper circumstances and if the counters are still phase locked, the receiver then discards the previously stored character and inverts the counter. If the receiver detects that it has received an erroneous character, such as one having multiple or no PPM pulses, the receiver will simply respond with the reject control character REJ. In such a case, the transmitter will respond with an RTXx which causes the receiver to discard the previously stored character and invert the counter.