PLC is a device, which is used to control a machine or process as per the human control sequence. A PLC monitors inputs, makes decisions based on its program, and controls outputs to automate a process or machine.
Advantages
• Smaller physical size than hard-wire solutions
• Easier and faster to make changes
• PLCs have integrated diagnostics and override functions
• Diagnostics are centrally available
• Applications can be immediately documented
• Applications can be duplicated faster and less expensively