| 摘要 |
PURPOSE:To rationally control the length of a queue, by installing means which sets a reference value of the length of queue and comparing condition, and outputting and displaying to the outside a condition coincidence signal when the comparing condition is satisfied in the compared result. CONSTITUTION:A register 21 which sets a reference value (g) of the length of queues, another register 22 which sets comparing conditions (h), and a comparator 23 are installed. The comparator 23 controls an input-possible signal C and an output-possible signal (f) by comparing the counted value (end address of queue 12) of a counter 4 with that (first address of queue 13) of another counter 5, and, at the same time, compares the length of a queue with the reference value (g) supplied from the register 21. When the comparator detects that the comparing conditions (h) are satisfied, the comparator 7 outputs a conditions coincidence signal (i) and displays it. Therefore, when the length of a queue reaches a previously fixed optional condition, it can be displayed to the outside, and thus, the queue can be controlled pertinently. |
