PLC is a programmable logic controller, mainly used for the logic control, which is composed of a host and an input / output unit. The input and output is the main switch signal,
programmable logic controller manufacturer has now developed a simulation signal; the main principle is to accept the input signal to the controller, according to certain logical relationship, the operation on the controller, and the output to the output unit.
In the user view, a detailed analysis of the internal circuit of CPU is not necessary, but the working mechanism of the various parts or should have the enough understanding. Control the CPU controller CPU,
plc digital input module ,explaining and executing command which reads the instruction.
