Method of control of the different operating states of a data bus system
In a method of controlling the different operating states of a data bus system, message passing on the data bus can be switched into an inactive operating state, during which message passing on the data bus is deactivated, or into a normal operating state, in which message passing on the data bus is activated, with different communication modes being provided for control of the different message passing states on the data bus. In a first communication mode during the normal operating state of the data bus, messages containing network information are transmitted as necessary over the data bus. In another communication mode, messages containing network information in identical message format are transmitted in a repeating manner over the data bus and status information is evaluated that determines if the data bus system must remain in the normal operating state. Based on a change in status information, another communication mode assumes control of the message passing states on the data bus, and in one of the communication modes the transfer of messages containing network information in identical message format is waived in part or in whole.
1 . A method for controlling different operating states of a data bus system, wherein message passing on the data bus can be switched into an inactive operating state in which message passing on the data bus is deactivated, and a normal operating state in which message passing on the data bus is activated, wherein different communication modes are provided for control of the different operating states on the data bus, with messages containing network information being transferred over the data bus, as necessary, in a first communication mode during the normal operating state of the data bus; said method comprising:
in another communication mode, transmitting messages containing network information in identical message format, in repeating manner over the data bus;
evaluating a status information which defines whether the data bus system must remain in the normal operating state;
based on a change in the status information, said another communication mode assumes control of the message passing states on the data bus; and
in one of the communication modes, the transfer of messages containing network information in identical message format is waived at least in part.
2 . The method according to claim 1 , wherein the status information is transmitted to each control device over the data bus or by status input separate from the data bus.
3 . The method according to claim 1 , wherein:
in addition to the inactive and normal operating states, a further state is provided for power up or power down;
in the further operating state, transfer of messages containing network information in identical message format is not waived.
4 . The method according to claim 1 , wherein said method is applied in a network management of a single data bus.
5 . The method according to claim 1 , wherein the messages containing network information in identical message format contain network information describing a present communication state of the data bus, relative to the control device.
6 . The method according to claim 1 , wherein depending on the status information, the data bus system is powered down to the inactive operating state, for which a data bus power-down operating state is provided during which no regular bus messages are transmitted.
7 . The method according to claim 2 , wherein status information is provided to the control devices, indicating if the data bus must to be in the normal operating state.