(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...

1. Stand-alone control system The stand-alone control system is controlled by one PLC to control one device or one simple production line, as shown in Figure 7-1. The composition of the stand-alone control system is simple, the number of I/O points required is less, the storage capacity is small, and when the model of PLC is selected, whether there is a communication network at present.

Recently, the signing ceremony of the strategic cooperation between Bureau Veritas and Hollysys and the functional safety certification ceremony of Hollysys valves were held in the Hangzhou base of Hollysys. Mr. Ye Jiong, General Manager of Bureau Veritas Technology Center, Mr. Zhong Aimin, Director of Product Certification Center, Mr. Yang Yang, Sales Director of Eastern Region, and Mr. Yang Yang, Director of Functional Safety ...

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.

The "2023 China Automation + Digital Industry Annual Conference", "The 19th CAIMRS and Digital Leaders Forum" and the "Annual Award Ceremony" were successfully held in Suzhou. The theme of this summit is "Powerful Digital Intelligence, Junfa New Industry", combined with post-epidemic recovery, digital intelligence, and new industrialization.

1. The physical structure of the interface 1. RS232 interface: One of the computer communication interfaces, usually RS-232 interface in 9 pin (DB-9) or 25 pin (DB-25) form, generally there will be two sets of RS-232 interfaces on personal computers, respectively called COM ...

(1) Development in the direction of integration: the development of standardized data communication links and communication networks, and the formation of a large system of various single (multi) loop regulators, PLCs, industrial PCs, NCs and other industrial control equipment to meet the requirements of factory automation and adapt to the general trend of openness. (2) To the intelligent ...

1. Check before power-on If the cable insulation resistance meets the requirements (greater than 5M ohms), check the cable insulation resistance test record, and spot check the actual measurement if necessary. Check that all power cables, signal cables, and communication buses should be connected. Control stations, operator stations, engineer stations, etc.

DCS is properly blacked out When the DCS needs to be powered off for maintenance due to overhaul or other reasons, we often directly power off the DCS, but sometimes this non-standard operation will bring serious consequences, such as configuration loss, PID parameter loss, etc. So there is a need for blackouts and re-on...

1. View the data on the monitoring screen When the following situations occur, it means that there is a problem with the control system, and the microcomputer maintenance personnel should be notified immediately for maintenance, and the operator should go to the site to deal with it. (1) Frequently changing data does not change for a long time, and several or all data do not ...

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 ...

1. What is a communication protocol? A communication protocol is an agreement between two parties to a communication. The agreement includes uniform provisions on data format, synchronization mode, transmission speed, transmission steps, error detection and correction mode, and control character definition, etc., which must be complied with by both parties to the communication. Therefore...

In general, DCS control systems require two types of grounding: protective ground and working ground (logical, shielded, etc.). For systems equipped with safety barrier explosion protection measures, such as those used in the chemical industry, intrinsically safe premises are also required. 2.1 Protected areas (CG, Cabinet Grounding...)

1. Configuration of the system and controller The configuration of systems and controllers focuses on reliability and load factor (including redundancy). The communication load rate must be controlled within a reasonable range, and the load rate of the controller must be balanced as much as possible to avoid the occurrence of "high load" problems. 2 ...

The control system needs to establish the input and output channels of the signals, which is called I/O. The I/O in a DCS is generally modular, with one or more I/O channels on one I/O module for connecting sensors and actuators (control valves). The control unit of the DCS: a process control station is ...

01 Node bus failure The node bus material is usually a coaxial cable, so as long as there is a cable disconnected, the communication of all devices on the bus will be paralyzed, which will cause serious phenomena such as data loss, equipment stoppage and operation interruption, and may eventually directly or indirectly cause huge ...

Resistive coupling interference In the process of work, many factories ignore the problem of wire aging. When a variety of signal lines are transmitted together, other transmission signals will be affected due to the aging and leakage of the insulation material on the wire, and other transmission signals will be interfered with. ...

01. Power supply The DCS power supply system is mostly a "dual backup hot redundant power supply", and the prevention and control of power failures is mainly reflected in the inspection and daily maintenance. Generally speaking, as long as the unit is normal ...

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 ...

(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. 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.