Arrangement for monitoring a two-wire bus line

US5781585A · kind A · utility

Assignee

• Daimler-Benz AG · DE

Inventors

• Jurgen Dorner · Wissen, DE
• Bernhard Rall · Ulm, DE
• Roland Haun · Bad Marienberg, DE

Key dates

• Filing date: Apr 11, 1995
• Grant date: Jul 14, 1998
• Expiry date: Apr 11, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L43/0811
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

An arrangement for monitoring a two-wire bus line for serial transmission of digital data includes a bus subscriber receiving circuit coupled to the two-wire line and including three comparators each having two inputs and an output for producing a logical output signal in dependence of signals at the two inputs. A signal line voltage on each wire of the two-wire bus line is applied, respectively, to the two inputs of a first one of the comparators and one of the two signal line voltages, an auxiliary voltage is applied, respectively, to the two inputs of a second one of the comparators and the other of the two signal line voltages and an auxiliary voltage being applied, respectively, to the two inputs of a third one of the comparators. A logic circuit is coupled to the outputs of the three comparators for simultaneously receiving the logical output signals of at least the second and third comparators and for signaling a fault-free condition of the bus system if all received logical output signals from the comparators are in agreement, and for signaling a fault if all received logical output signals from the comparators are not in agreement.