Link protocol for RS 232 communications
US5142538A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1990 |
| Grant date | Aug 25, 1992 |
| Priority date | — |
| Expiry date | Apr 19, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/14
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
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 tra…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.