Patent ID: 8861370

Claim:
A method for testing a communications network having a central bus guardian (CBG) to detect a faulty condition associated with the CBG, the method comprising: supplying a communications schedule to the CBG; causing test data to be transmitted between different buses that are connected to the CBG according to the communications schedule; and determining the faulty condition associated with the CBG based on whether or not the test data is received according to the communications schedule, wherein causing the test data to be transmitted comprises causing a first communications device connected to a first bus of the different buses to transmit a test data frame by way of the CBG to a second communications device connected to a second bus of the different buses in a time slot according to the communications schedule, and wherein determining the faulty condition associated with the CBG comprises determining there is a fault associated with the CBG if the test data frame is not received by the second communications device in the time slot when the communications schedule instructs the CBG to forward the test data frame to the second bus in the time slot or if the test data frame is received by the second communications device in the time slot when the communications schedule instructs the CBG not to forward the test data frame to the second bus in the time slot.