Method for the operation of a data bus, and data bus system

A data bus system, comprising:

• data lines and multiple bus participants connected with the data lines, said bus participants being respectively represented by a microprocessor system;
• the bus participants respectively having an input plug and an output plug such that the respective bus participant can be connected to an existing data bus by means of the input plug, and an extension of the data bus can be connected to an additional bus participant at the output plug;
• the bus participants respectively having a termination resistor to terminate the data lines;
• the termination resistors being respectively connected in series with a switching element connected with a control logic to activate said switching elements;
• the control logic being connected with two control terminals of the output plug such that the control logic opens the corresponding switching element in the event that these two terminals of the output plug are shorted;
• the input plug of the bus participant having a bridge at the terminals corresponding to the two control terminals of the output plug which, at the last bus participant, then leads to a situation that its control lines remain open at the plug and the control logic can close the switching element which thus terminates the bus in a region of the last bus participant;
• and
• the bus participants being provided with software modules on a non-transitory computer-readable media to perform, when connecting a new bus participant to the data bus, the steps of
• generating a request bus message by the new bus participant, said message containing a preliminary participant identification number as an identifier, said number being derived from a serial number of the new bus participant, the request bus message being arbitrated in the data bus by means of the identifier;
• assigning a final participant identification number for the new bus participant after the receipt of the request bus message with the preliminary participant identification number, the final participant identification number having fewer digits than the serial number of the new bus participant;
• using the final participant identification number by the new bus participant as an identifier for further bus messages by said new bus participant;
• and
• after the connection of each new bus participant, the data bus is initialized, and wherein during the initialization bus messages are used with an identifier in which a complete serial number is entered as said identifier, and each bus participant sends a corresponding request bus message for allocation of the final participant identification number, and after the initialization a different type of bus message is used that has a shorter identifier in which the final participant identification number can be entered.

A software module for a data bus, comprising:

• a non-transitory computer-readable medium comprising a computer program for operation of a data bus to which multiple bus participants each with a respective serial number specific to them are connected, said computer program performing the steps of:
• connecting a new bus participant to the data bus;
• generating a request bus message by the new bus participant, said message containing a preliminary participant identification number as an identifier, said number being derived from a serial number of the new bus participant, the request bus message being arbitrated in the data bus by means of the identifier;
• assigning a final participant identification number for the new bus participant after the receipt of the request bus message with the preliminary participant identification number, the final participant identification number having fewer digits than the serial number of the new bus participant;
• using the final participant identification number by the new bus participant as an identifier for further bus messages by said new bus participant;
• and
• after the connection of each new bus participant, the data bus is initialized, and wherein during the initialization bus messages are used with an identifier in which a complete serial number is entered as said identifier, and each bus participant sends a corresponding request bus message for allocation of the final participant identification number, and after the initialization a different type of bus message is used that has a shorter identifier in which the final participant identification number can be entered.

A printer, comprising:

• multiple assemblies connected with one another with a data bus;
• multiple bus participants each with a respective serial number specific to them connected to the data bus;
• and
• means for operating the data bus according to the following steps:
• connecting a new bus participant to the data bus;
• generating a request bus message by the new bus participant, said message containing a preliminary participant identification number as an identifier, said number being derived from a serial number of the new bus participant, the request bus message being arbitrated in the data bus by means of the identifier;
• assigning a final participant identification number for the new bus participant after the receipt of the request bus message with the preliminary participant identification number, the final participant identification number having fewer digits than the serial number of the new bus participant;
• using the final participant identification number by the new bus participant as an identifier for further bus messages by said new bus participant;
• and
• after the connection of each new bus participant, the data bus is initialized, and wherein during the initialization bus messages are used with an identifier in which a complete serial number is entered as said identifier, and each bus participant sends a corresponding request bus message for allocation of the final participant identification number, and after the initialization a different type of bus message is used that has a shorter identifier in which the final participant identification number can be entered.