Hollysys was invited to participate in the 2023 China Petroleum and Chemical Industry Digital Transformation and Intelligent Development Conference and delivered a keynote speech

The choice between a programmable logic controller (PLC) and a distributed control system (DCS) is a case-by-case analysis, as the requirements for the control system vary depending on the application. You can start from the following aspects! PLC and DCS PLC ...

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. 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).

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 ...

1. Budget for input and output (I/O) points When budgeting I/O points, the appropriate margin should be considered, usually based on the calculated number of input and output points, and then add 10%-20% of the expandable, and after the margin, it will be used as the budget data of input and output points. When ordering in practice, it is also necessary to rely on the manufacturer's ...

1. The configuration of the system and controller should focus on reliability and load rate (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 distribution of system control logic should not be too much.

First, the working environment (1) Temperature The PLC requires that the ambient temperature is 0-55oC, and it cannot be placed under the components with large heat generation during installation, and the surrounding ventilation and heat dissipation space should be large enough. (2) Humidity In order to ensure the insulation performance of PLC, the relative humidity of the air ...

1. DCS is a "distributed control system", while PLC (programmable controller) is just a control "device", which is the difference between the two. The system can realize the function and coordination of any equipment, and the PLC equipment only realizes the function of this unit. 2. In terms of networking, the DCS network is ...

1. High reliability Because DCS disperses the system control function on each computer, and the system structure adopts a fault-tolerant design, the failure of one computer will not lead to the loss of other functions of the system. In addition, due to the fact that the tasks undertaken by the various computers in the system are comparatively ...

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 ...

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 ...

In December 2020, the equipment of Sinopec Qingdao Petrochemical Co., Ltd. (hereinafter referred to as Qingdao Petrochemical) 5 million tons/year oil refining integration project, which was upgraded and transformed by Hollysys, was successfully operated, marking the successful completion of the DCS equipment upgrading task. This upgrade is a major development for Sinopec Industrial Holdings.

1. Correctness (low debugging cost) First of all, the PLC program must be able to work correctly to meet the requirements of the actual control process. This is the essence of the PLC program, and if you don't do that, nothing else makes sense. 2. Reliability (low maintenance cost) Not only to ...

PLC is essentially a kind of computer dedicated to industrial control, and its hardware structure is basically the same as that of a microcomputer, and its basic composition is as follows: 1. Power supply The power supply of the PLC plays a very important role in the whole system. If you don't have a good, reliable power system that is ...

With the inclusion of "exploring the construction of digital twin cities" in the 14th Five-Year Plan, the field of intelligent transportation is being endowed with more new business value. Recently, Century Qualcomm and Hollysys reached a strategic cooperation, based on the principle of "giving full play to advantages, mutual promotion, long-term cooperation, mutual benefit and win-win", ...

In order to improve the anti-interference ability of the PLC system, we should start from the design. In the anti-interference design of specific projects, products with strong anti-interference ability can be selected to improve the anti-interference of equipment and systems by suppressing interference sources, cutting off or attenuating the transmission path of electromagnetic interference, and using software means.

(1) There are three forms of programmable controller: relay output, thyristor output, and transistor output. (2) The wiring of the output terminal is divided into independent output and common output. When the output relay or thyristor of the PLC is activated, the two output terminals of the same number are turned on. In different groups, you can ...

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.

1. Preliminary preparations Engineering configuration is operated at the engineer station, and before engineering configuration, it is necessary to have the necessary tools and information, specifically: Tools: refers to the hardware environment and software environment used in engineering configuration, usually refers to the ...

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.