| 摘要 |
PURPOSE:To relieve the load of a central processing unit by providing a polling signal controlling in common plural control stations to a control signal for the central processing unit. CONSTITUTION:A signal (global station address) X capable of controlling in common a control station is specified to the central processing unit 1. The control station has a function to detect that the transmission of other stations is stopped and the detection operates a counter circuit 5. A prescribed initial value is set to the counter circuit 5 at each control station. The counter circuit 5 counts the number of detections and is operated by the first signal X and the count value is zeroised. The transmission of a control station 3-n is enabled after the transmission of other stations 3-0-3-(n-1) is finished. The multi-station polling is finished by the central processing unit applying polling to plural control stations only once. |
