YPN104C 3AFE81014477 ABB

From the user’s point of view,it is not necessary to analyze the internal circuit of the CPU in detail,but the working mechanism of each part should be well understood.The controller of the CPU controls the work of the CPU,which reads the instructions,interprets the instructions and executes the instructions.But the working rhythm is controlled by the oscillating signal.The calculator is used to perform digital or logical operations and work under the command of the controller.The register participates in the operation and stores the intermediate result of the operation,and it also works under the command of the controller.

CPU speed and memory capacity are important parameters of PLC,they determine the working speed of PLC,the number of IO and software capacity,etc.,so limit the scale of control.

在使用者看来，不必要详细分析CPU的内部电路，但对各部分的工作机制还是应有足够的理解。CPU的控制器控制CPU工作，由它读取指令、解释指令及执行指令。但工作节奏由震荡信号控制。运算器用于进行数字或逻辑运算，在控制器指挥下工作。寄存器参与运算，并存储运算的中间结果，它也是在控制器指挥下工作。

CPU速度和内存容量是PLC的重要参数，它们决定着PLC的工作速度，IO数量及软件容量等，因此限制着控制规模。