| 摘要 |
PURPOSE:To attain a steady access from a normal channel device by providing a means to forcibly release occupancy by the channel device, in which abnormality is generated with another normal high order channel device, when the abnormality is generated in the high order channel device. CONSTITUTION:The means of setting and releasing an occupying condition is the same as a means by a reserve command and a release command from channel devices 1 and 2. The means which can forcibly release the occupying condition is a means to be operated by a priority reserve command from the other channel device. When mutual input and output control devices 3 and 4 receive this priority reserve command from the high order channel device, the occupying condition for the other input/output control device is forcibly released. Thus, an input/output device can be used from the other channel device and the unfair occupying condition of the input and output device due to a channel trouble can be released. |
