Hollysys automation solutions

1. It is used for switching control The ability of PLC to manipulate switching quantities is very strong. The number of points in and out of the control, less than a dozen points, dozens of points, more can be hundreds, thousands, or even tens of thousands of points, because it can be networked, the number of points is almost unlimited, no matter how many points can be controlled, the control ...

How a PLC controller works 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 ...

1. Rich networking and interface functions, easy to deploy It supports 5G/4G/3G/WIFI/Ethernet, WAN/optical fiber and other network access modes, network port/serial port/IO port/CAN port and other equipment access, and supports LoRa wireless transmission, disconnection reconnection and multi-network mutual backup function. 2. Abundant ...

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.

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...

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...)

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 ...

1. Circuit isolation The isolation of analog circuits is more complex, mainly depends on the accuracy requirements of the transmission channel, the higher the accuracy requirements, the higher the cost of the channel; However, when the performance requirements rise to the main contradiction, the isolation components should be selected based on performance, and the ...

(1) High reliability DCS is designed to be fault-tolerant, so that when a computer fails, it does not cause the system to lose other functions. In addition, because the tasks undertaken by the individual computers in the system are relatively simple, it is possible to adopt a specific structure and ...

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.

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) Computing function The computing functions of a simple PLC include logic operation, timing and counting functions; The operation functions of ordinary PLC also include data shift, comparison and other calculation functions; More complex arithmetic functions include algebraic operations, data transmission, etc.; There are also analog PIDs in large PLCs.

(1) When the PLC and the host computer (or touch screen) form a monitoring system, there are many times when there are "manual", "automatic" and other control modes on the screen (generally when there is only one multiple). You can use the "MOV" command in the program. For example, when "manual" is selected, the constant 1 MO ...

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 ...

(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. 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 ...

Since the reform and opening up, China's economy has developed rapidly, and many enterprises have improved production efficiency by introducing foreign production equipment and DCS systems. However, with the growth of the use years, many foreign DCS systems and equipment have gradually aged and are not suitable for the current production needs, so they are localized.

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.

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 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 ...