ABB 3BHE003855R0001PLC控制系统CPU处理器模块

ABB  3BHE003855R0001PLC控制系统CPU处理器模块

ABB  3BHE003855R0001PLC控制系统CPU处理器模块

控制器由程序计数器、指令寄存器、指令译码器、时序产生器和操作控制器组成。

控制器分组合逻辑控制器和微程序控制器，两种控制器各有长处和短处。组合逻辑控制器设计麻烦，结构复杂，一旦设计完成，就不能再修改或扩充，但它的速度快。微程序控制器设计方便，结构简单，修改或扩充都方便，修改一条机器指令的功能，只需重编所对应的微程序；

　　要增加一条机器指令，只需在控制存储器中增加一段微程序，但是，它是通过执行一段微程。具体对比如下：组合逻辑控制器又称硬布线控制器，由逻辑电路构成，完全靠硬件来实现指令的功能。

　　控制器（controller）是指按照预定顺序改变主电路或控制电路的接线和改变电路中电阻值来控制电动机的启动、调速、制动和反向的主令装置。由程序计数器、指令寄存器、指令译码器、时序产生器和操作控制器组成，它是发布命令的“决策机构”，即完成协调和指挥整个计算机系统的操作。 

ABB  3BHE003855R0001PLC控制系统CPU处理器模块

The controller is composed of a program counter, an instruction register, an instruction decoder, a timing generator and an operation controller.

The controller is divided into combinatorial logic controller and microprogram controller. The two controllers have their own advantages and disadvantages. Combinatorial logic controller design is troublesome, complex structure, once the design is completed, it can not be modified or expanded, but its speed is fast. Microprogram controller is convenient in design, simple in structure, easy to modify or expand, modify the function of a machine instruction, only need to reprogram the corresponding microprogram;

To add a machine instruction, one simply adds a microprogram to the control memory, but it does so by executing a microprogram. The specific comparison is as follows: The combined logic controller, also known as the hard-wired controller, is composed of logic circuits and completely relies on hardware to achieve the function of instructions.

controller (controller) refers to the master device that changes the wiring of the main circuit or control circuit and changes the resistance value in the circuit to control the start, speed regulation, braking and reverse of the motor in accordance with the predetermined order. Composed of program counter, instruction register, instruction decoder, timing generator and operation controller, it is a "decision mechanism" that issues commands, that is, to complete the coordination and command of the operation of the entire computer system.