In the PLC, CPU module, I / O modules, namely what role

CPU module is the control center of the PLC. It functions in accordance with the procedures given PLC system receives and stores from the programmer type of user programs and data; check the power supply, memory, I / O and watchdog timer status, and diagnose user program syntax error. plc IO module is the interface between PLC and site control interface input channels. Therefore, the manufacturer of the PLC power supply design and manufacturing very seriously. Programming plays a role in the design and commissioning of the plc.

Plc cpu

Since the 1960s, the United States launched a programmable logic controller (Programmable Logic Controller, PLC) to replace the traditional relay control system, PLC has been rapid development,cpu module plc has been widely used around the world. Meanwhile, the function of the PLC is also improved. With computer technology, signal processing technology, control technology continues to develop network technology and the continuous improvement of user requirements, PLC increased the analog processing and motion control functions on the basis of the amount of processing on the switch. Today's modular plc is no longer limited logic control, motion control, process control and other fields also play a very important role.
Programmable logic controllers initially only logic control circuit function, so was named the programmable logic controller, and later with the continuous development of these original features simple computer module already includes logic control, timing control, analog control Many of the features, such as multi-machine communication, the name was changed to the PLC (Programmable Controller), but because plc cpu modules is also shorthand for PC and PC (Personal Computer) shorthand for conflict, but also as a result of many years of usage, people or programmable logic controllers often use this title, and the term is still used in the acronym PLC.