Abstract
Along with science's and technology's unceasing development, the automatic valve obtained the widespread application in people's daily life, simultaneously to its aspect and so on performance and security requests is also getting higher and higher. This article introduced Simens S7-226 series PLC and the Mitsubishi E700 series frequency changer's in automatic valve control application, has analyzed automatic valve's work process, has designed the corresponding trapezoidal chart document, has realized the automatic valve by opening, the waiting, the closure entire process.
