Communication system for actuation of multiple subscribers in a motor vehicle, and data bus for such a communication system

A communication system for a motor vehicle, the communication system comprising:

• a controller;
• a data line;
• a plurality of subscribers, said subscribers being connected in series one after another by means of said data line to form a subscriber chain, each of said subscribers having a control unit, said subscribers being actuated by said data line and a communication protocol, the communication protocol having a linear array of data packets, wherein a subscriber-specific data packet is provided for each of said subscribers, a respective subscriber-specific data packet is divided into a subscriber portion and an information portion, the information portion containing a piece of information that a respective subscriber can write to about a status of the subscriber portion, the respective subscriber using a first subscriber-specific data packet with a status “Not received” as its applicable data packet and chances the status to “Received;
• and
• at an end of the communication protocol there is a control data packet contained for said controller that said controller uses to check whether the subscriber chain is correct.

An operating method, which comprises the steps of:

• providing a communication system, containing:
• a controller;
• a data line;
• a plurality of subscribers, said subscribers being connected in series one after another by means of said data line to form a subscriber chain, each of the subscribers having a control unit, the subscribers being actuated by the data line and a communication protocol, the communication protocol having a linear array of data packets, wherein a subscriber-specific data packet is provided for each of the subscribers, a respective subscriber-specific data packet is divided into a subscriber portion and an information portion, the information portion containing a piece of information that a respective subscriber can write to about a status of the subscriber portion, the respective subscriber using a first subscriber-specific data packet with a status “Not received” as its applicable data packet and changes the status to “Received”;
• and
• the controller and the subscribers forming a ring structure and the controller at an end of the subscriber chain checks whether the subscriber chain is correct;
• and
• using the communication system in a motor vehicle for the subscribers.