Consisting of CPU

plc cpu internal structure can be divided into several main parts unit, arithmetic unit, a storage unit and clock control.

Calculator is a computer data processing center, which is mainly composed of an arithmetic logic unit (ALU: Arithmetic and Logic Unit), registers and status registers. ALU mainly to complete the binary information of fixed-point arithmetic operations, logic operations, and various shift operations. General-purpose register is used to hold operands and intermediate results participate in operation. Status register have different requirements in different machines, the program, the state bit is typically used as a branch instruction determination condition.

plc controllers is the control center of the computer, which determines the automated computer processes running. It is not only to ensure the correct implementation of the program, but also to be able to deal with unusual events. The controller generally includes an instruction control logic, timing control logic, bus control logic, interrupt control logic sections.