Hollysys PLC - Precautions in the operation of PLC (1)

(1) Select the appropriate PLC model and I/O points, and select the special function module when there are special function requirements. (2) Familiar with the selected PLC programming instructions and compilation software. (3) Carry out soft component planning, including internal relays, holding relays, data registers, ...

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...

On September 19, 2022, the XCon2022 Security Focus Information Security Technology Summit was successfully held in Beijing. More than 10 technical experts, heads of security departments, and front-line security experts from well-known domestic network security enterprises shared in-depth topics at the meeting.

(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. 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.

Examining the hierarchical structure of DCS, DCS level and control management level are the two most basic links that make up DCS. The process control stage specifically realizes the decentralized control functions such as signal input, conversion, operation and output. The controls at the process control level vary in different DCS, ...

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.

DCS spare parts In the process of using the DCS control system, its management is more important. The requirements of general DCS spare parts management are summarized in four aspects: storage, inspection, preparation for use, and use. 1. Storage DCS system, spare module storage should meet the requirements ...

Whether it is a new unit or an upgraded DCS, the equipment of the system and controller should focus on the reliability and load factor (including redundancy) objectives. The load rate planning of the communication bus must be controlled within a reasonable range, and the load rate of the controller should be balanced as much as possible.

1. Lack of motivation It may sound simple, but it's good to check the simple stuff first. Thoroughly inspect all power connections and cables for damage that could cause a short circuit. Make sure your power supply is functioning properly. Use a voltmeter to check if the grounding and voltage are correct. 2. Bad ...

3. Main anti-interference measures (1) Reasonable treatment of power supply to suppress the interference introduced by the power grid For grid disturbances introduced by the power supply, an isolation transformer with a shielded ratio of 1:1 can be installed to reduce the interference between the equipment and the ground.

Serial communication is done using 3 wires: (1) ground, (2) sending, and (3) receiving. Since serial communication is asynchronous, ports are capable of sending data on one wire and receiving data on the other. Other threads are used for handshakes, but are not required. Serial communication is the heaviest ...

1 Universal serial port module Based on the serial port communication module to realize the network connection, the network structure is shown in Figure 1, the form of computer link is adopted, the corresponding settings are carried out in the configuration software of the host computer, and the communication can be carried out with multiple PLCs without programming, and the FXlS of Mitsubishi ...

Kunming Changshui International Airport is one of the eight regional hub airports in China and one of the five national large-scale gateway hub airports. With the rapid economic development of Yunnan Province, the aviation business volume of Kunming Airport has grown rapidly.

PLC understands the interrupt function in this way, when understanding the interrupt, we must first understand the PLC operation cycle or the scanning cycle, it is necessary to say that the PLC sequential control cycle execution process, which is the premise of understanding the interrupt, must be mastered, divided into three parts, input processing, program processing, output ...

Since the day of the birth of PLC, it has occupied the core position of the entire automatic control system. There are also many discussions about the development direction of PLC, whether it is predicted that PAC will replace PLC from 10 years ago, or during this time, some people even say that PLC is no longer needed in the future Industry 4.0 era...

DCS is the English abbreviation of distributed control system (Distributed Control System), distributed control system is referred to as DCS, which can also be literally translated as "distributed control system" or "distributed computer control system". The decentralized control system is based on the microprocessor, and the control function is decentralized.

1. PLC programmable logic controller (programmable controller). 2. DCS system pays more attention to the field of process control. Such as chemical, smelting, pharmaceutical, etc. It mainly monitors and controls some field parameters, while PLC focuses on logic control. machining). Of course, the PLC's ...

1. Realize remote control of industrial field equipment; 2. The PLC industrial gateway realizes remote upgrade of equipment firmware, downloads the program, and can flexibly access various equipment management platforms; 3. Realize remote control of industrial site touch screen and remote mapping of configuration screens; 4. PLC industry ...

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 ...