Hollysys PLC - Calculation of the amount of pulses in PLC

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. Power off 2. Cleaning the ash can not only clean the surface, but also clean the internal card key of the controller 3. If there is a supporting UPS, open the UPS and clean the ashes 4. After cleaning the ash, check whether the card and relay are loose, and tighten them if they are loose 5. The relays with frequent actions should be cleaned regularly.

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.

2. Interference in the control system and its sources On-site electromagnetic interference is one of the most common factors in PLC control system and most likely to affect the reliability of the system. It is therefore essential to know the source of on-site disturbances ...

1. The switching signal of PLC controls the inverter The output point and COM point of the PLC (MR type or MT type) are directly connected to the STF (forward start), RH (high speed), RM (medium speed), RL (low speed), and SG input ports of the inverter. PLC can control the frequency conversion through the program ...

In order to further strengthen the comprehensive cooperation with Shaanxi Traffic Control Group, on August 11, 2022, Xu Yue, Chairman and Co-President of Hollysys Group, visited Zhang Wenqi, Secretary of the Party Committee and Chairman of Shaanxi Traffic Control Group, and the two sides conducted in-depth exchanges and cooperation on topics such as business ecology and smart highways.

1. Scanning technology When the PLC is put into operation, its working process is generally divided into three stages, namely input sampling, user program execution and output refresh. The completion of these three phases is called a scan cycle. During the entire operation, the CPU of the PLC scans at a certain speed ...

On October 15, 2022, the scientific and technological achievement of "SCADA system development and refined oil pipeline application based on independent chips and operating systems" jointly completed by South China Branch of National Petroleum Pipeline Network Group Co., Ltd. and Hangzhou Hollysys Automation Co., Ltd. successfully passed the China Petroleum and Chemical Industry Co., Ltd.

CNC machine tool PLC (programmable logic controller) has the following common faults in the operation process, and the following corresponding solutions are taken for the faults in the work engineering to make the equipment operate normally. 1. The power grid fluctuates too much, and the PLC does not work It is manifested as no output of the PLC. Check first ...

1. Switch logic control Switching logic control is the basis of PLC. It is the first use case and the most extensive of all. Replace the previous relay circuit control and realize logic sequence control; It can be used for the control of stand-alone equipment, and can also be used for group control and ...

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.

1. Input of switch command signal The input signal of the inverter includes a switch-type command signal that controls the operating status such as operation/stop, forward/reverse, section speed, and joging. Frequency converters usually make use of relay contacts or components with relay contact switching characteristics (such as crystals).

There are many new developments in the field of DCS-related, which are mainly manifested in the following aspects. (1) The system function is developing in the direction of openness. The structure of traditional DCS is closed, and it is difficult to be compatible with DCSs from different manufacturers. The open DCS will allow users to set a larger system ...

1. Data backup When carrying out maintenance, we must cut off the power, data backup between power outages is an important link, for the data that needs to be archived for a long time, you can back up the historical trend data to the mobile hard disk, and then turn off the Windows-based operating system (Note...

DCS usually adopts a hierarchical and progressive structure, each level is composed of several subsystems, and each subsystem achieves a number of specific finite goals, forming a pyramid structure. Examining the hierarchical structure of DCS, DCS level and control management level are the two most basic links that make up DCS. Process control...

1. The thermocouple uses a compensation wire, and there can be a node in the middle, but the corresponding compensation cable must be used to directly connect to the DCS thermocouple module, such as the LLMUX card in HONEYWELLTPS. Minimize nodes to reduce interference. In addition, in the DCS configuration, it is necessary to select the corresponding thermocouple model, and supplement the ...

On December 18, 2020, the "8th Member Congress and 2020 Zhejiang Enterprise Leaders Summit" hosted by Zhejiang Enterprise Confederation, Entrepreneur Association and Industrial Economics Federation (hereinafter referred to as the "Three Associations" of Zhejiang Province) was held in Hangzhou. At the conference, the top 100 in Zhejiang Province in 2020 were commended.

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 ...

(1) From the point of view of control methods The control logic of the electrical control system adopts hardware wiring, and the series connection or well connection of the electrical mechanical contact is combined into the control logic, and the connection is complex, large in size, and in large power consumption, and it is difficult to change or increase the function after the system is formed. Other than that...

Merit: 1. High reliability: The DCS system has multiple redundancy, backup and recovery mechanisms, which can ensure the high reliability and stability of the system. 2. Sensitivity: The DCS system can be customized according to different industrial processes to meet different control requirements. 3. Efficiency: D...