What is a PLC

it is a kind of real-time system is different from the PC. Traditional motor control system is given priority to with relay, whenever change design, almost all need to make the whole system, not only time-consuming and inefficient. At the same time because of the relay and contact, poor contact, wear volume of faults, thus leading to higher costs, low reliability, difficult to repair, and other issues. In order to improve these disadvantages, the DEC published for the first time in 1969: programmable controller.

program controller is called at the beginning of the published. Hereinafter referred to as PLC, the first purpose is to replace the relay, so as to perform relay logic and other timing and counting functions of sequence control is given priority to, so also called sequence controller, its structure is also like a microcomputer, so also can be called a microcomputer programmable controller ( MCPC) Until 1976, the American association of motor manufacturing to formally named Programmable Controller, can Controller, hereinafter referred to as PC, because of the personal computer Is very common, and often cooperate with programmable controller is used, in order to distinguish between the two, so generally called the programmable controller PLC to be respectively.

on the market at present there are many different kinds of PLC controller, in accordance with the manufacturer and the suitable place to varies, but each of these labels can be in accordance with the complexity of unit is divided into large, medium and small; And factories and schools usually use small PLC, with Japanese F series and A series PLC in our country is affected by the love of the people. But this CAI will be given priority to with mitsubishi FX2 PLC controller were introduced, users can have a deeper understanding of PLC, can be more handy when using PLC. Programmable controller is available below inner basic structure, its internal unit including CPU, input module, output module three branches, PLC controller CPU will by input module obtain input components produced by the signal, and then one by one, remove from the memory to original program writer entered in the control instruction, through logical calculus after operation department, then the results through the output module to drive the output of the external components.