Subscriber station for serial bus system, and method for transmitting data in serial bus system

Abstract

The invention relates to a subscriber station (10; 20; 30) for a serial bus system (1) and to a method for transmitting messages (4; 5; 50) in the serial bus system (1). The subscriber station (10; 20; 30) comprises a transmission / receiving device (12; 22; 32) for serially transmitting a message (4; 5; 50) on a bus line (3) to at least one other subscriber station (20; 30; 10) of the bus system (1) or for serially receiving a message (4; 5; 50) from the bus line (3), wherein the transmission / receiving device (12; 22; 32) is designed to generate a first or second bus level (471, 481; 471, 482; 472, 482) on the bus line (3) upon request in the event that the transmission / receiving device (12; 22; 32) is not operating as the transmitter of the received message (4; 5; 50), and the transmitting / receiving device (12; 22; 32) is designed in such a way that for the transmitting / receiving device (12; 22; 32) acts as a function of the received message (4; 5; 50), instead of using a third bus level (472; 482) to generate the first or second bus level (471, 481), the third bus level is lower than the bus level (471, 481) replaced by the third bus level (472; 481, 482), and however, on a bus line (3), one of the two bus levels (471, 481; 471, 482; 472, 482) can be distinguished in the bus system (1).

Description

technical field [0001] The invention relates to a subscriber station for a serial bus system and a method for transmitting data in a serial bus system. Background technique [0002] In a serial bus system, the data to be transmitted between subscriber stations are coded in temporally consecutive bits and sent sequentially in messages according to a predetermined communication protocol to the bus and are thereby transmitted via the bus. The communication protocol specifies which data or bits are encoded in which part of the message. In wired bus systems, at least one line is used as a transmission medium for transmitting data between subscriber stations. [0003] For example, serial communication protocols with bit arbitration are known, such as Classical CAN and CAN FD, which use recessive and dominant bus levels as two different bit levels. In this case, the bus level is selected taking into account the transmission medium such that the dominant level can override the rec...

AI Technical Summary

Problems solved by technology

[0006] The problem is that the bits on this bus distort asymmetrically with differently strongly driven bus levels

This asymmetry limits the bit rate for serial transmission

[0007] Another problem is that especially the edge from dominant to recessive tends to overshoot due to signal reflections

This limits the available fraction of bit time, especially for sampling and thereby further limits the maximum available bit rate

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