| 摘要 |
PURPOSE:To improve the transmission efficiency of a looped transmission line by allowing a trigger station to supervise the priority of polling at each period and apply polling of high and low 2nd priority at the next period to the highest priority where the polling of the next priority of a low level is not finished. CONSTITUTION:When the polling with a priority level 3 is finished and the next period comes, the polling of the minior priority ''1'' is applied to the major priority higher in major priority of high-order level at the next period. In such a case, the polling of the minor priority 2 is not executed to the major priority 3 higher than the major priority 2 of the priority level 3. That is, the polling of the priority level 7 is applied to the priority level 5 by using a trigger signal TRG. Since the polling of the priority level 6 is not executed, useless polling in a conventional example is not executed. |
