A Microprocessor-Based Time Sequence Controller for Process Control Applications

The effectiveness of microprocessor-based systems for realizing random logic controllers (which were traditionally built using electromechanical logic) is illustrated by the design of a time-based sequence controller using a 4-bit microprocessor. It is shown that the microprocessor-based controller is cheaper than its electromechanical counterpart, at the same time offering improved performance, versatility, and increased value through the addition of extra features without hardware complications. The use of low-cost design kits for microprocessor-based system development for simple dedicated control applications is also emphasized.