| 摘要 |
PURPOSE:To avoid a complication of a long time waiting device of a specific device by continuing to feed a carrier signal showing an using of a common bus until a peculiar time zone assigned by the device comes even if an information transfer is completed. CONSTITUTION:When a transfer of an information is completed and a transfer completion pulse 14 comes, an FF is set and signal lines 18 and 19 go low level. Then, a comparator 3 detects a coincidence of an output of a counter 1 and a device number setting switch 2, namely continues to feed a carrier signal indicating an using of a common bus until the completion of a peculiar time zone assigned to the device is detected. Thereby, other device cannot use a common bus. However, when an assigned peculiar time zone is completed, the FF is reset, a carrier signal line 12 goes to a high level and other device can use the common bus. In this manner, even when an information transfer is completed, a signal showing the transfer of the information is not stopped, thereby an using sequence of the common bus can be maintained and a long time waiting of a specific device and a complication of the device can be prevented. |
