Hollysys DCS - What is DCS distributed control system?

1. The function of PLC PLC is a general industrial automatic control device with microprocessor as the core, integrating computer technology, automatic control technology and communication technology, which has high reliability, small size, strong function, simple program design, flexible and universal and maintenance methods.

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...)

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...

Recently, Hollysys successfully signed a contract with Luxi Chemical Group Co., Ltd. (hereinafter referred to as Luxi Chemical) for a 1.2 million tons/year bisphenol A equipment project. The project is a key project in Shandong Province in 2021, which will not only greatly improve the competitiveness of Luxi Chemical polycarbonate in the industry, but also have a significant impact on China's phenol ...

The steps of DCS system troubleshooting include: (1) Check the fault caused by improper use. Common types of operational faults include operator errors, terminal wiring faults, module installation faults, and power supply failures. (2) Troubleshoot the improper operation of the DCS system ...

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. 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 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.

Analog signal: refers to a continuous current signal or voltage signal, and analog signal can be divided into standard signal and non-standard signal. Switching signal: It can be divided into active signal and passive signal, which is basically an on-off signal, and can be measured on and off with a multimeter ohm. ...

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 ...

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. 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)

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...

In general, PLCs are extremely reliable devices with a very low failure rate. The probability of hardware damage such as the CPU of the PLC or software running errors is almost zero; If the PLC input point is not caused by strong current intrusion, it will hardly be damaged; The normally open point of the PLC output relay, if it is not a short circuit of the peripheral load ...

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 ...

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...

(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. 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 ...

On the morning of October 20, 2021, at the Epec Industrial Products Exhibition, Hollysys released a new 100% localized system - 'HOLLiAS MACS IC fully autonomous and controllable DCS system'. The system integrates the controller microkernel architecture independently developed by Lisi, embedded ...

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 ...