| 摘要 |
PURPOSE:To operate the entire device succeedingly by providing a means counting the duration time of a time slot acquisition request signal from a selected sender, raising alarm if request signals are stacked for a prescribed time or over, and assigning the time slot to the sender of the next priority to attain the use of a bus for the sender. CONSTITUTION:Assuming that the state of a counter circuit 1 is (n). In such a case, this state is specified by a selection command input 20 and a signal input line 21 to be selected at the (200+n)th order of the selection circuit 2 is selected. When the (200+n)th selected signal input line 21 is activated for a prescribed time or over, a timer circuit 4 detects it and raises an alarm signal onto an alarm line 100. Since the alarm signal is fed to the other input of a control gate 5, enable input 10 of the counter circuit 1 is activated to advance the counter circuit 1. As a result, the state of the counter circuit 1 is brought into (n+1) and the (200+n+1)th selected signal input line 21 of the selection circuit 2 is selected by the selection command input 20. |
