| 摘要 |
PURPOSE:To achieve sure discrimination even at a secondary station requiring longer time for the discrimination of polling sequence, by adding a dummy pattern to the polling sequence transmitted from a primary station. CONSTITUTION:A polling sequence transmitted from a primary station consists of a flag pattern F, a group address G, a polling command UP, a frame check sequence FCS and a gore head pattern GA indicating the last of the sequence. Secondary stations in loop connection link telegraphic messages after rewriting the gore head pattern GA in the polling sequence into the flag pattern F and finally a new gore head pattern GA is added. A plurality of flag patterns F are linked at the back of the frame check sequence FCS. As a result, the processing can be finished in the polling sequence even at a station with slow processing speed. |
