【Daily Question 20090320~21】What are the key points for selecting a DCS? (Already summarized)

Number and model of I/O devices; Number and model of controllers; Network architecture; Number and model of operator stations; Number and model of engineer stations; Number and model of servers; Overall topology; Process characteristics and corresponding function libraries; Features of the user interface. That’s all for now, otherwise there won’t be enough space to write more. It seems there aren’t many people left who want to speak, so I’ll add a few more points. Although scoring has been completed, everyone can still discuss the matter. For users, reliability is of primary importance, that’s true. Functionality and ease of use come in second and third place. Solutions tailored for specific industries are also important, as they ensure the product’s usability, maintainability, and availability of support services. Considerations should also be given to online upgrades, offline upgrades, and bus expansion in the future. I don’t really agree with price being a factor – it’s not part of the technical aspects. Last edited by wopale3 on 2009-3-20 20:05

The requirements upstairs are mostly related to technology; I’ve learned them. Next, we will cover technologies beyond technical aspects: the application of DCS in various industries. Choose domestic or imported; investment size, scalability, technical support, spare parts supply. Last edited by s1j2 on 2009-3-20 11:42.]

Reliability: That is, whether the system can operate stably over the long term. Practicality: Whether the technical specifications of all aspects of the control system can fully meet the requirements of production control ； Whether the system software, including configuration software and monitoring software, is complete, thorough, reliable, and user-friendly; whether users can carry out configuration and on-site debugging by themselves; and whether maintenance is easy after operation. Price: Is the price of the system within the range acceptable to users and is it reasonable? Operability: Is the human-machine interface of the control system easy for operators to use, and are the displays intuitive? ； Considering China’s national conditions, such as whether the system is in Chinese, and whether there are Chinese-language reports, etc. Maintainability: Whether the fault diagnosis functions are robust and the fault indications are clear ； Is it easy to repair the hardware? Can users replace the templates by themselves to carry out repairs, and can these templates be inserted or removed while the system is still running without affecting its normal operation? ； Are spare parts readily available, delivered in a timely manner, and at reasonable prices? ； Can users receive timely assistance from the manufacturer’s technical staff when they encounter difficulties in maintaining it on their own? What is the level of training provided to users and how convenient it is, what are the costs, and is it possible to carry out operations on actual machines?

In addition to what was mentioned above, the project scale and investment budget also need to be taken into consideration. Compared to analog instruments, DCS is more complex and requires higher technical expertise. When selecting a DCS system, the following points should be noted: First, in theory, DCS can be used in various process systems as it is a universal solution; however, the manufacturers of DCS systems specialize in certain fields. For example, HOMEYWELL is mainly used in the petrochemical industry, while BAILEY’s N90 and INFI90 are primarily used in power systems. ROSEMOUNT’s RS3 and Δ-V are mostly used in the chemical industry. However, it cannot be denied that different manufacturing processes have certain specific requirements; for example, power plants must be equipped with voltage regulation devices and SOE, the petrochemical industry requires selective control, and the cement industry needs compensation for large time delays in control systems. These factors also need to be taken into account when making selections. Second is cost-effectiveness, which should be considered from the perspective of the DCS’s price and the expected benefits it will generate. Third is the technical expertise of the contractor, that is, their familiarity with which process steps and the DCS itself. Fourth is after-sales service; foreign manufacturers usually charge high prices for accessories and spare parts, and fail to provide them in a timely manner. Fifth is the technical advancement of DCS, which refers to the use of proven cutting-edge technologies in the system, as well as its potential for further development and viability. This includes the openness and interconnectivity of DCS systems, the use of fieldbuses, and support from third-party software.

From a technical perspective, what was said on the second floor is quite comprehensive. From a management standpoint, the simplest approach is to ask the DCS manufacturers to provide examples of projects in which their control systems have been used, then visit several companies in person, listen to the opinions of the users, and after that make a comprehensive decision regarding which DCS system to choose based on factors such as cost-effectiveness, functionality, stability, maintenance requirements, and availability of spare parts. Of course, it also depends on the salesperson’s ability to deceive people. . .