| 摘要 |
PURPOSE:To uniform the priority of transmission control shared by each station by applying polling simultaneously to each station by means of the floating master system so that each station receiving the simultaneous polling decides the propriety of data transmission. CONSTITUTION:Polling is applied simultaneously to all slave stations from an optical master station. Each station receiving the polling activates a timer 9 when there exists a data desired to be transmitted to the own station, and when it is confirmed that there exists no signal on a transmission line 2 by a transmission line signal detector 5 after time-up, a required data is transmitted. A slave station transmitted the data is designated as the next master station and the role of master station is transferred sequentially among the slave stations. |
