YPH105E ABB

PLC is developed from the principle of relay control.It stores instructions for performing logical operations,sequence control,timing,counting,and operations,and controls various types of machinery or production processes through digital input and output operations.The control program compiled by the user expresses the technological requirements of the production process,and is stored in the user program memory of the plc in advance.When running,the content of the stored program is executed one by one to complete the operations required by the technological process.

PLC是由继电器控制原理发展起来的，它以存储执行逻辑运算、顺序控制、定时、计数和运算等操作的指令；并通过数字输入和输出操作，来控制各类机械或生产过程。用户编制的控制程序表达了生产过程的工艺要求，并事先存入plc的用户程序存储器中。运行时按存储程序的内容逐条执行，以完成工艺流程要求的操作。