PLC common function instructions What are the typical PLC functions?

PLC common function instructions

The following are several commonly used functional instructions of PLC:

LD (load) instruction: loads the specified value or data into a register or variable.

OUT (output) instruction: controls the operation of output devices, such as opening or closing motors, valves, etc.

AND instruction: used for logical operations to determine whether two input signals are true at the same time.

OR instruction: used for logical operations to determine whether at least one of the two input signals is true.

NOT instruction: used for logical operations to invert the input signal.

Timer instruction: used for timing operation, timing according to the preset time.

Counter instruction: used for counting operation, counting according to the preset counter value.

Move instruction: Used to move data from one register or variable to another.

Compare instruction: used to compare whether two values ​​or data are equal or in a certain size relationship.

Jump instruction: Jump to the specified program segment according to preset conditions.

The above are some commonly used functional instructions of PLC. They can be combined and called according to different control logics and control algorithms to realize complex automatic control operations.

What are the typical PLC functions?

The functions of PLC (Programmable Logic Controller) can be customized according to different application scenarios and control requirements, but generally speaking, typical PLC functions include the following aspects:

Input/output control: PLC can receive signals from various sensors and input devices, and control the operation of various output devices, such as motors, valves, lights, etc., to achieve automated control.

Motion control: PLC can realize various complex motion control functions, such as positioning, motion speed control, acceleration and deceleration control, position tracking, etc.

Logic control: PLC can perform various logic operations, such as comparison, addition, subtraction, multiplication, division, logical AND, OR, etc., to realize different control logic and control algorithms.

Timing/Counting Control: PLC can realize various timing and counting functions, such as timer, counter, pulse control, etc.

Data processing: PLC can process the input signal and store the processed data in the internal memory for subsequent use.

Network communication: PLC can exchange data and communicate with other devices through various communication methods (such as Ethernet, Modbus, etc.) to achieve network control between devices.

Automatic monitoring/alarm: PLC can automatically monitor equipment and production processes, detect equipment failures and abnormal conditions in a timely manner, and issue alarms to ensure the normal operation and safety of the production process.

In general, PLC has the advantages of flexibility, programmability, stability, reliability, and easy maintenance, and is widely used in various industrial automation control fields.