High reliability and strong anti-interference ability

Traditional relay control systems use a large number of intermediate relays and time relays. Due to poor contact of the contacts, malfunctions are prone to occur. PLC replaces a large number of intermediate relays and time relays with software, leaving only a small amount of hardware related to input and output. Wiring can be reduced to 1/10~1/100 of the relay control system, greatly reducing faults caused by poor contact.

High reliability is a key performance of electrical control equipment. Due to the use of modern large-scale integrated circuit technology and strict production processes, PLC has high reliability with advanced anti-interference technology for its internal circuits. For example, the F-series PLC produced by Mitsubishi Corporation has an average processing time of up to 300000 hours. The average working time of some PLCs using redundant CPUs is longer. From the perspective of the external circuit of PLC, using PLC to form a control system, compared with relay contactor systems of the same scale, the electrical wiring and switch contacts have been reduced by hundreds or even thousands, and faults have been greatly reduced. In addition, the PLC has a hardware fault self detection function, which can promptly issue alarm information when a fault occurs. In application software, users can also incorporate fault self diagnosis programs for peripheral devices, enabling circuits and equipment in the system other than PLCs to also receive fault self diagnosis protection. It is not surprising that the entire system has * reliability.

Fully equipped hardware, complete functions, and strong applicability

PLC has developed into a series of products of various scales, including large, medium, and small, and has been standardized, serialized, and modularized. It is equipped with a complete variety of hardware devices for users to choose from, and users can flexibly and conveniently configure the system to form systems with different functions and scales. The installation and wiring of PLC are also very convenient, usually connected to external wiring through terminal blocks. PLC has strong load capacity and can directly drive general solenoid valves and AC contactors, which can be used in industrial control applications of various scales. In addition to logical processing functions, modern PLCs mostly have complete data processing capabilities and can be used in various digital control fields. In recent years, a large number of functional units of PLC have emerged, which has penetrated into various industrial controls such as position control, temperature control, CNC, etc. With the enhancement of PLC communication capabilities and the development of human-machine interface technology, it has become very easy to use PLCs to form various control systems.

Easy to learn and use, highly welcomed by engineering and technical personnel

PLC, as a general industrial control computer, is an industrial control equipment designed for industrial and mining enterprises. It has an easy interface and a programming language that is easily accepted by engineering and technical personnel. The graphical symbols and expressions of ladder diagram language are quite similar to relay circuit diagrams, and the functions of relay circuits can be easily implemented with only a small number of switch logic control instructions from PLC. This has opened the door for people who are not familiar with electronic circuits, computer principles, and assembly language to use computers for industrial control.

The design, installation, and debugging of the system require minimal effort, are easy to maintain, and are easy to modify

The ladder diagram program of PLC generally adopts the sequential control design method. This programming method is very regular and easy to master. For complex control systems, the design time for ladder diagrams is much less than that for designing circuit diagrams for relay systems.

PLC uses storage logic instead of wiring logic, greatly reducing the external wiring of control equipment, greatly shortening the design and construction cycle of control systems, and making maintenance easier. More importantly, it makes it possible for the same device to change the production process through program modifications. This is very suitable for production occasions with multiple varieties and small batches.

Small size, light weight, low energy consumption

Taking ultra small PLCs as an example, the newly produced varieties have a bottom size of less than 100mm, which is only equivalent to the size of a few relays. Therefore, the volume of the switchgear can be reduced to 1/2~1/10 of the original size. It weighs less than 150g and consumes only a few watts of power. Due to its small size and easy installation inside machinery, it is an ideal control device for achieving mechatronics integration.