Abstract
This article uses Simens S7-200 series PLC to enter travels vies to answer first system's design, vies to answer first is one kind can cause any competition and the competitive game manifests fairly, the fair electronic equipment. In competition, for accurate, fair, judges the first viing to answer first intuitively, designs vies to answer first usually by the numerical code demonstrated that the light, the sound and so on many kinds of methods instruct the first viing to answer first. At the same time, the systems control procedure uses the trapezoidal chart design, and can the order complete overall system's automatic control, has the movement to be reliable, reduces merits and so on production cost, enhancement production efficiency.
key word: Vies to answer first digital demonstration automatic control PLC
