| 摘要 |
PURPOSE:To improve diagnostic resolution, to shorten the time of test and diagnosis execution, and to reduce the load on the whole system by reporting an error to a common control part when transmit and receive data do not coincide with each other. CONSTITUTION:Transfer data from a host device 1 to a communication controller 2 is returned to the host device 1 by the common control part 3 in a test and diagnosis execution state, and the host device 1 tests and diagnoses the common control part 3. When it is judged that the control part 3 is normal, the host device 1 specifies a free circuit adapter 4 and sends out test data. This adapter 4 sets the return state of data by a control circuit 12 to store transmit data in a receiving data register 13 through a multiplexer 17 and then a comparing circuit 19 compares the data with the data in a transmitting register 15. When the result of the comparision shows dissidence, a dissidence signal is sent out to a control part 3 through a line 204 and reported to the host device 1. |
