| 摘要 |
PURPOSE:To shorten the diagnostic time of a common bus and to improve diagnostic efficiency by diagnosing an I/O control device, and at the time of detecting defective operation, deciding all the common bus I/O parts and the common bus as doubtful portions. CONSTITUTION:A common bus diagnostic means 5 is provided with two diagnostic phases, i.e. a phase 1 for diagnosing a channel control device 3 and a phase 2 for diagnosing the farmost end I/O control device 2-n. In the phase 1, information transmitting/receiving operation from a control part 1 to the device 3 through a route TPH-1 is checked. When the operation is available, information transmitting receiving operation from the device 3 to the device 2-n through a route TPH-1 is checked in the phase 2. If abnormality is detected, the whole part relating to the common bus, e.g. all the I/O part of the common bus 4, the I/O part of the bus 4 for any one of the I/O control devices 2-1 to 2-n and the bus 4 itself are displayed on a display part as doubtful portions. Consequently, the diagnostic time can be shortened. |
