Programmable logic control applied to a coal preparation plant complex

The programmable Logic Controller (PLC), at its present stage of evolution, is now considered as a mature control system. The PLC combines the solid-state reliability of hardwired logic and computer control systems with the simplicity of a relay ladder logic. Relay symbolic programming through a function-oriented keyboard provides a means which plant personnel can easily become accustomed to work with. In a large coal facility, it is shown that the control engineer can provide improved control flexibility with the advanced capabilities of the PLC.