Data bus, particularly in motor vehicles

A slave node for a data bus system for use in motor vehicles and automation technology wherein slave nodes execute functions based upon addressed command messages from an electronic main control unit that is coupled to a data bus and wherein the command messages contain an identifier field for addressing the commands, a limited amount of identifying information being provided for the identifier field, comprising:

• a first, non-volatile memory area in which function numbers of functions executable by the slave node are permanently stored;
• a second, programmable memory area in which, for each function number stored in the first memory area, a piece of identifying information provided for the identifier field is storable via a special command message received from the main control unit.

An electronic main control unit for a data bus system for use in motor vehicles and automation technology wherein slave nodes coupled to the data bus execute functions based upon addressed command messages from the electronic main control unit coupled to the data bus, said command messages containing an identifier field for addressing the commands and for which a limited amount of identifying information is provided, each function executable by the slave nodes of the data bus being assigned at least one function number, the electronic main control unit comprising:

• means for creating a special command message by which a piece of identifying information for the identifier field is storable in a slave node for each function number stored therein.

A method of using a data bus for a motor vehicle having slave nodes that execute functions based upon addressed command messages from an electronic main control unit that is also connected to the data bus, wherein the command messages contain an identifier field for addressing the commands for which a limited amount of identifying information is provided, the method comprising the acts of:

• for each function executable by slave nodes of the data bus, assigning at least one function number permanently storable in the slave nodes;
• and
• as a result of a special command message from the electronic main control unit, for each of the function numbers permanently stored in the slave nodes, programming identifying information allocated to the function numbers that can be stored in the slave nodes.