Abstract
Along with science's and technology's swift development, PLC entered the daily production, life each aspect, the PLC application has become the essential content in the industrial control domain. The article introduced realizes in the drill hole special purpose machine through the PLC control hydraulic system to the work piece processing, and gives its PLC control system's smooth functional diagram and the trapezoidal chart programming, through experimental verification design rationality.
key word: PLC drill hole special purpose machine order functional diagram trapezoid