Hollysys PLC - maintenance steps of PLC control cabinet

1. Use the analog output module of the PLC to control the analog output module of the inverter The analog output module of the PLC outputs a 0-5V voltage signal or a 4-20mA current signal, which is used as the analog input signal of the inverter to control the output frequency of the inverter. This control method is simple to wiring, but it needs to be selected and changed.

(1) Overhaul projects DCS system overhaul is carried out in the random group of main equipment overhaul, and the overhaul project includes the following: 1) Conduct a comprehensive inspection of the control equipment and make a record. 2) Copy the configuration of all modules, and verify the marks and addresses of the modules. 3) Qing ...

1. Peripheral circuit component failure This type of failure often occurs in the failure of the PLC after a certain period of work. In the PLC control loop, if there is a component damage fault, the PLC control system will immediately and automatically stop working. The input circuit is a PLC that accepts switching quantities, analog ...

1. The role is different A PLC (Programmable Logic Controller) is an electronic system designed for digital operations in an industrial environment. The inverter is the application of frequency conversion technology and microelectronics technology to control the AC motor by changing the frequency of the motor working power supply.

According to the different functions of PLC, PLC can be divided into three categories: low-grade, mid-range and high-end. (1) Low-grade PLC Low-grade PLC has basic functions such as logic operation, timing, counting, shifting, self-diagnosis, monitoring, etc., and can also have a small amount of analog input/output, arithmetic operation, math...

1. The output accuracy is as high as 0.05%, which greatly improves the operation efficiency of the system. 2. The full-scale output of the channel signal is 0-22.7mA, and the output range is wide; 3. It can be adapted to the enhanced base to achieve channel resistance to 220VAC; 4. It has a perfect channel signal diagnosis function, which can be realized.

According to the structural form of PLC, PLC can be divided into two categories: integral type and modular type. (1) Integral PLC The integral PLC is a centralized power, CPU, I/O interface and other components in a chassis, which has the characteristics of compact structure, small size and low price. Small PLC ...

(1) The PLC adopts the working mode of centralized sampling and centralized output, which reduces the influence of external interference. (2) The working process of PLC is the process of cyclic scanning, and the length of cyclic scanning time depends on the speed of instruction execution, the length of the user program and other factors. (3) Output ...

The choice between a programmable logic controller (PLC) and a distributed control system (DCS) is a case-by-case analysis, as the requirements for the control system vary depending on the application. You can start from the following aspects! PLC and DCS PLC ...

1. Configuration of the control loop The configuration of the control loop is essentially to use the various basic functional modules provided by the system to form a variety of actual control systems. At present, the configuration methods provided by various DCSs are different, and they can be summarized as having a specific computing module connected ...

On August 16, 2021, the Tarim Oilfield Natural Gas Ethane Recovery Project, the largest natural gas deep processing base in Xinjiang (1), a key project of PetroChina, was successfully completed and put into operation, with stable operation and the production of qualified ethane products. Tarim Oilfield Natural Gas Ethane Recovery Project ...

On March 15, the 2023 China Petroleum and Chemical Industry Digital Transformation and Intelligent Development Conference was held in Tai'an, Shandong. The conference aims to strengthen the construction of "intelligent oil and gas fields, intelligent petrochemicals, intelligent chemicals and intelligent oil and gas pipeline networks", and lead China's petroleum and chemical industry to achieve intelligent transformation.

LE series is a new generation of high-performance small and medium-sized PLC products launched by Hollysys, which is suitable for small and medium-sized industrial equipment control and distributed long-distance monitoring applications. LE-PLC combines the compact structure of small PLC products with the abundant functional advantages of medium-sized PLC products, and can support up to 20 local IOs or long ...

1. Field instrument equipment failure: Field instrumentation equipment includes various transmitters, various switches, actuators, loads and components of various temperatures that are directly connected with the production process. If the field instrument fails, it directly affects the control function of the DCS system and the operator's ...

1. Preliminary preparations Engineering configuration is operated at the engineer station, and before engineering configuration, it is necessary to have the necessary tools and information, specifically: Tools: refers to the hardware environment and software environment used in engineering configuration, usually refers to the ...

1. Relay output circuit This type of output circuit form can be either DC or AC. The output circuit form of PLC relay allows the load to be generally below AC250V/50V, the load current can reach 2A, and the capacity can reach 80-100VA (voltage × current), so ...

In recent years, the State Administration of Safety Supervision, the Ministry of Industry and Information Technology, the Ministry of Education, and the Ministry of Finance have successively launched a number of national policies to implement major decision-making projects such as vocational skills improvement actions, safety skills improvement actions, and vocational education reforms, aiming to create a highland for the training of technical and skilled talents.

On October 18, 2022, the China Intelligent Transportation Association released the list of winners of the "2022 China Intelligent Transportation Association Science and Technology Award", which includes the Science and Technology Progress Award, the Technology Invention Award, and the Outstanding Innovative Talent Award. Among them, Beijing Hollysys System Engineering Co., Ltd. ...

1. Communication network failure: communication network faults are generally easy to occur at the contact bus and local bus, or caused by wrong address identification. 2. Node bus failure: The transmission medium of the node bus is generally coaxial cable, some use token signal transmission mode, and some use ...

1. The connection line is loose and the contact is poor When the run indicator of the PLC turns red, the position of the plug changes to green with a manual move, indicating that the plug is loose, and it is best to replace the new connecting wire, and the plug is frequently plugged and unplugged, which will also lead to poor contact. 2. Strong electrical interference (external)