Although many names such as relays, timers and counters are often used in the ladder diagram programs used by LS PLC, LS PLC does not have these hardware physically, but uses memory and program programming to do logic control and editing, and connects the output components to external mechanical devices for physical control. As a result, the hardware space required for the controller can be greatly reduced. In fact, the PLC fulfillment ladder diagram program works line by line, first reading the ladder diagram code into the CPU in the form of scanning, and then performing the control operation.
In the whole scanning process, there are three major processes, "Input Status View", "Program Fulfillment", and "Output Status Update" are described as follows:
Process 1 "Input Status View" first checks the status of each point switch or sensor connected to the input element (1 or 0 represents on or off), and writes its status into the corresponding position Xn in memory.
Process 2 "Program Fulfillment": Extract the ladder diagram program into the CPU line by line for calculation, if the program fulfillment needs to input the contact status, the CPU will directly query and take it out from the memory. The calculation results of the output coil are stored in the corresponding direction in the memory, and will not be reflected to the output Yn for the time being.
Process 3 "Output Status Update": Update the output status of Process 2 to the PLC output contact, and return to Process 1. These three processes are called the PLC scanning cycle, and the time required to complete is called the PLC response time, if the PLC input signal time is less than this response time, there is a possibility of misreading. After each program execution and before the next program execution, the output and input status will be updated once, so this mode of operation is called "program completion regeneration" at the output and input terminals.
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(2) The wiring between the inverter and the motor should consider the line electricity.
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The principle and function of the power production contactor
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1. Select the corresponding category of contactor according to the control object, operation times and application category of the contactor.
2. Select according to the rated voltage of the line at the application location.
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LS Electric reached a strategic cooperation with Nandu Power Supply and Changzhou Kunlan
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1. As soon as the inverter of the heat exchange station is opened, the pressure transmitter jumps randomly;
2. Use the inverter to control the water supply, the pressure transformer is used as the signal to collect the pressure, and the pressure transformer is disturbed by the inverter;
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The given way of the inverter - LS generates electricity
Frequency given meaning and given method
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Inverter harmonic suppression method - LS power generation
1. Install an appropriate reactor
The input side and the output side of the inverter are connected in series with suitable reactors to absorb harmonics and increase the impedance of the power supply or load, so as to achieve the purpose of pressing harmonics to reduce electromagnetic radiation in the transmission process. After pressing the harmonic current, the power factor is changed from the original ...
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LS Electric helps Cisco Smart City build an industry benchmark
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LS has reached agreements with Doosan and Hanwha in Korea on a business model for vacuum power generation
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Inverter harmonic calculation method - LS power generation
1. Method 1
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Faulty failure with soft starter - LS generates electricity
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