| 摘要 |
PURPOSE:To make it possible to swiftly grasp the variation of the supervisory item by the central station when it has occurred in plural terminal stations, by sending out a time sharing report signal to the central station from each terminal station, in the centralized supervisory system having both the cyclic polling system and the status change starting system. CONSTITUTION:The terminal stations are called in order, the supervisory information of these terminal stations is replied to the central station by the reply signal b1-bn, and also the prescribed time lag t1 is provided between the call signal (a) for calling the terminal station from the central station, and the reply signals b1- bn executed by the terminal stations. And the terminal station whose supervisory information has been varied is made to report by the report signals b1-bn in said time lag, and the central station preferentially calls the terminal station which has sent out said report signals b1-bn, and the supervisory information of its terminal station is replied. In this centralized supervisory system, the time lag t1 starting from the send-out end time of each call signal (a) is assigned to each terminal station in advance so that it is not overlapped in time, and the central station is made to send out the report signals b1-bn in the respective assigned time zones to the terminal station whose supervisory information has been varied. |
