虽然计算机控制技术已经产生，但是PLC控制因为它的高性能、成本低、并且对恶劣的环境有很强的适应能力而在工业控制的广泛应用中保持优势。而且，尽管硬件的价格在逐渐下跌，据估计，根据Frost和Sullivan对PLC市场的调查研究表明，每年销售硬件的价格要比销售PLC的价格（一千五百万）至少多出八十亿美元。PLC的创造者Richard E. Morley十分肯定的认为目前PLC市场是一个价值五十亿的工业-functional design. Programmable controller for the user, is a non-contact equipment, the procedures can be changed to change production processes. The programmable controller has become a powerful tool for factory automation, widely popular replication. Programmable controller is user-oriented industries dedicated control computer, with many distinctive features.