ONLINE TEST SYSTEM FOR DISTRIBUTED DEVICE

摘要

PURPOSE:To test each controller in the online state by providing in addition a testing device on a bidirectional common bus and adding a test circuit part, which transmits and receives data to and from the bidirectional common bus synchronously with the testing device, to each of plural controllers. CONSTITUTION:A testing device 5 which tests the functions of controllers is connected to the bidirectional common bus 1, and each controller is provided with the test circuit part which transmits and receives data to and from the bidirectional common bus synchronously with the testing device, and specific time slots on the bidirectional common bus are used between the testing device and test circuit parts to test transmission and reception functions of controllers to the bidirectional bus. That is, the online test is performed without disconnecting controllers since transmission and reception functions of controllers are tested simultaneously with the operation of the other time slots.