Remote control system for motor vehicle related devices

US5940007A · kind A · utility

Assignee

• Mercedes-Benz Group AG · DE

Inventors

• Horst Brinkmeyer · Waiblingen, DE
• Arthur Hipp · Tauberbischofsheim, DE
• Daniel Hoffmann · Herrenberg, DE
• Gunter Schwegler · Waiblingen, DE
• Dirk Weigand · Leipzig, DE

Key dates

• Filing date: Feb 24, 1997
• Grant date: Aug 17, 1999
• Expiry date: Feb 24, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2209/84
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A system and method for operating a remote control having a portable remote control unit which can control at least one function unit. The remote control unit and the function unit are connected with one another by way of a bidirectional data communication link, by which data can be transmitted by means of a symmetrical coding method. The remote control unit sends a learn mode reporting signal in a secret coding information learn mode to the controllable function unit which, in the learn mode, in turn, sends back an acknowledgment signal. Upon receipt of the acknowledgment signal, the remote control unit generates new secret coding information by means of the coding algorithm, as a function of basis secret coding information and of the previous secret coding information, and sends the new secret coding information to the function unit. The function unit then replaces the previous secret coding information with the new secret coding information and emits an acknowledgment signal, upon the receipt of which the remote control unit, in turn, replaces the previous secret coding information with the new secret coding information.