Network interface circuit with fast change from passive state - has difference amplifier with inputs from switches coupled to bus and to resistor network for determining input state

摘要

The interface for a computer network of the type used in a motor vehicle system in which it may be employed for operation of ignition, brakes, gears, etc., has an interface stage (12) and a microcomputer (11). The interface module contains a controller module (13) that contains a differencing receiver (14). The inputs to the module (RX0,RX1) are provided by a pair of FET switches (S1,S2). Inputs to the switch contacts are provided by a bus coupler (15). Other inputs are provided a resistor network (R1-R3) that provides a specific state following disconnection from the bus. ADVANTAGE - Provides fast change from passive state.