Method for fault-tolerant communication under strictly real-time conditions

摘要

A method for fault-tolerant communication under strictly real-time conditions in a local network uses a double bus architecture for reporting faults and for tolerating global bus faults. An active fault detection and notification mechanism is provided in order to safeguard consistency in the case of a fault and in order to comply with time limits regarding transmission of data. During fault-free operation, all of the process data are transmitted in one of the redundant bus systems and status information is transmitted in the other bus system. In the case of a fault, each bus is used as a watchdog bus in order to notify the network subscribers of faults occurring in the respective other bus system. The method can be used in process-oriented control and automation systems which have stringent requirements regarding reliability and real-time behavior.