| 摘要 |
PURPOSE:To detect a faulty place swiftly and efficiently, to easily take proper steps for repairing, and to restore a system swiftly, by detecting whether a bus line is normal or not, in case when a fault has occurred. CONSTITUTION:A fault of a bus line BL is displayed by detecting a level signal a maximum threshold VLmaxof a level by which a logical element such as TTL element to be used for a system is regarded as low, and a minimum threshold VHmin of a level by which said element is regarded as high, by a window comparator C group which has been provided so as to correspond to each bus line BL, and an OR circuit OR to which an output of this window comparator C group is provided, and by leading said signal to displaying circuit D through the OR circuit OR. |
