What is PLC  ?



PLC, the full name is Programmable Logic Controller, programmable logic controller. In fact, it is an "industrial computer" that can work stably in a complex environment. It can process external switching signals, digital signals, analog signals, etc. through the internal central processing unit.

PLC is actually composed of single chip microcomputer and some peripheral circuits. The peripheral circuits also include modules such as relays and transistors. Function switching is realized through the combination of modules, which realizes rapid development and productivity, and reduces development time and various testing risks.

What is the role of PLC ?

To say the role of PLC has to say its role in the field of industrial control.

As we all know, PLC was applied to industrial production lines at the beginning of its birth. After nearly 50 years of development, PLC plays an increasingly important role in the field of industrial control.

PLC is also one of the core control devices in the modern industrial intelligent integrated control system. The intelligence here is intelligent manufacturing, which is what we often hear about Industry 4.0. Costs continue to rise, and intelligent manufacturing replaces most manual operations to achieve a double improvement in quality and efficiency. Therefore, for a long time in the future, the field of artificial intelligence will have broad prospects for development.

PLC not only plays a great role in the industrial field, but is also widely used in other fields, such as elevator control systems in various high-rise buildings, traffic light control circuits used in commanding traffic, music fountain control circuits seen in life, Control of advertising lights, etc.

The composition of PLC ?

The composition of PLC includes CPU (central processing unit), RAM (memory), and many ports: communication port, output port, input port, power port, and expansion port.

The expansion port can connect different modules.

What equipment does PLC control   ? 

In fact, the mechatronic equipment controlled by PLC consists of two major parts, one is the mechanical part and the other is the electrical part. For monitoring (touch screen, sensor, switch, knob, used to monitor switch quantity, digital quantity, analog quantity, temperature, current and voltage, etc.), execution (contactor, inverter directly controls motor, servo driver controls servo motor, stepper driver Control stepper motors, solenoid valves control hydraulic cylinders and air cylinders), PLC (as the brain of the device, when the role of a conductor, requires programming).

PLC control process of mechatronics equipment  ?

First of all, we decide what kind of PLC and what kind of instructions to use according to what actions the device should do.

For example, there are several motors and several solenoid valves to find the output point, several sensors and several switches to find the input point, and the output point + input point to determine the PLC type; then according to the process (the action of the machine) process) to determine how the PLC program instructions do.

The seven functions of PLC  ?

Logic comparison (greater than, less than, equal to), sequence control, mathematical operations (addition, subtraction, multiplication and division, etc.), high-speed counting and speed measurement, positioning control, process control, communication (remote networking).

Our PLC controls various devices through seven functions.

What are the conditions for learning PLC  ?

Basic electrical experience: circuit components and simple circuits, series and parallel, logic gate circuits, DC and AC, etc.

Fundamentals of Computer Programming: Computer Fundamentals and the C programming language.

Of course, you don't have to know these two basic contents before you can learn PLC.

Where to start learning PLC  ?

First of all, you must have a real PLC, because if you use simulation all the time, you will not be able to learn most of the functions of the PLC.

Then the PLC brands are mainly Siemens and Mitsubishi with relatively high market shares. Mitsubishi tends to think in the East, and Siemens tends to think in the West. Here we recommend several entry-level models with high cost performance.

Siemens ST20, SBCM01 communication control board, EMAM03 analog module; Mitsubishi FX3u-16mt-es-a, FX2n-2AD FX2n-2DA analog module; Delta DVP20EX2