| 摘要 |
PURPOSE:To improve the efficiency of polling service by switching the polling service level from a master station to a slave staion in response to the state of the slave station to eliminate waste. CONSTITUTION:The polling service level is changed over at each slave station depending on the presence of data transmission and receiving of slave stations 21-2n in a data transmission system of the polling addressing system where the line control is attained by an independent calling (polling) from the master station 1 to the slave stations 21-2n. Thus, the polling service is attained efficiently to each slave station without waste. |
