Why DCS hasn’t retired from the stage of history yet

In fact, this is just like how we all use computers, 386, 486, 586, Pentium machines. . . It is a considerable investment for an individual, and it is also something that is easy to use. Similarly, for an enterprise that has adapted to the traditional DCS control concept for a long time, they are not willing to accept the direct and indirect investment brought by a new control system as well as the short-term increase in debugging, personnel training, and maintenance costs. We have to be patient and let the fieldbus brew a little longer. This post was last edited by johnneyzj on 2008-2-18 23:06 ]

What is the concept of fieldbus? Can the author briefly explain it? Very interested

If we use fieldbus, don’t we need DCS? Fieldbus is just instrumentation technology. Today's DCS technology is already a complex system including data information, batch processing, production management, etc. Fieldbus is only the lowest level technology.

According to the definition of IEC and Fieldbus Foundation, fieldbus is a digital, bidirectional transmission, multi-branch communication network that connects intelligent field devices and automation systems. If there is communication, there must be a protocol. In this sense, fieldbus is a standard that defines the hardware interface and communication protocol. The essential principles of fieldbus are also reflected in the following six aspects. (1) On-site communication network to realize on-site digital communication of process and manufacturing on-site instruments or equipment ； (2) Field device interconnection, using only a pair of transmission lines, such as twisted pairs, coaxial cables, optical fibers and power lines, etc., to interconnect field instruments and equipment such as sensors, transmitters and actuators ； (3) Interoperability. There are many types of field instruments or equipment, and it is impossible to purchase them all from one manufacturing company. Fieldbus allows the selection of products with the highest performance and price ratio from each manufacturer to be integrated together to achieve "plug and play", that is, to connect instruments or equipment of different brands to each other and configure them in a unified manner. ； (4) Function decentralization, reform the three-level structure of DCS into the two-level structure of FCS, abandon the input/output unit and control station of DCS, and disperse the control functions to field instruments to form a virtual control station ； Therefore, field instruments should be intelligent multi-functional instruments ； (5) Communication line power supply. For low-power field instruments with intrinsic safety requirements, it is allowed to directly absorb energy from the communication line. ； (6) Open interconnection, the field bus is an open interconnection network, which can be interconnected with networks at the same level or at different levels to share resources and perform unified scheduling.

I think DCS will still be the system of choice for new projects in the next 10 years!

There is a process for the development of things. The application of DCS is now very mature and it is the peak period of DCS. However, FCS has just started. Many things are still conceptual and require a lot of practice to improve it. However, FCS is an inevitable trend in control development. As for when it will be completely replaced, it depends on the progress of technology.

The difference between DCS and FCS is that FCS pre-programs the simple control functions of the DCS card into the field instrument, so it can be transmitted centrally, thereby reducing signal attenuation. However, the investment is relatively large, and not all enterprises can afford it. Moreover, this investment depends on whether the device itself is worthwhile.

This title is too exaggerated. Even if fieldbus is widely used, DCS will not be replaced.

I agree with the point above that fieldbus technology is relatively advanced, but relatively speaking, instruments that meet its technology have not yet become popular, so they are expensive. As a factory project, whether advanced control is required depends on whether it is necessary and the investment cost.

Today's enterprises do not require advanced technology but mature technology and mainstream technology before they are willing to use it. It will take some time before fieldbus is widely used.

Any technology has a process of emergence, maturity and decline. As an emerging technology, fieldbus technology has a maturity level different from that of DCS. At this stage, there is no question of who will replace whom. Even in the future, it is difficult to say that technology will be rich and colorful. :lol

Fieldbus is the trend of automation development. Its main feature is on-site control, which is not inconsistent with DCS.

Agree with the point above, the possibility of fieldbus replacing DCS is very small, the reason: Many occasions in the chemical production process require explosion protection. Fieldbus, as the name suggests, is installed on site. In addition to realizing the basic function of control, DCS is currently involved in information processing and management of factory automation systems. Fieldbus can only replace the on-site control function of DCS. There is no need for any user to use an anti-riot computer as a server for factory information processing!

taylorliu's statement is wrong. Fieldbus does not mean using explosion-proof computers to process factory information. In fact, it is certain that fieldbus technology will become the mainstream of large-scale control in the future, but it cannot completely replace DCS, just like DCS cannot replace PLC. It has its own room for development, but it is inevitable for technological development that most of the space of DCS will be replaced by fieldbus. Due to the lagging development of fieldbus meter technology, there is still a long way to go before fieldbus technology can give full play to its strengths. Moreover, large-scale technologies like DCS will have great inertia and will suppress new technologies.

Agree with the point above. . . . If you deny taylorliu's point of view, your explanation is wrong. . . . DCS and FCS are both control systems, and now PLC can be used as a control system. . What you choose to use depends on the number of control points and automation level of your project. If there are a lot of points. If you use DCS and only have wiring cabinets, I think your house can be filled with them. And there is no room for cables. In this case, you should consider using an FCS system. . . . . We must consider the analysis in terms of funds and usage, and we cannot analyze what is used and what is eliminated from a technical perspective! ! ! ! !

Everyone above has their own merits, I think the main ones are in terms of capital and instrumentation technology. Most companies still have old models of field instruments that do not support bus technology. Emerging bus instruments are immature and expensive. Can ordinary small investment companies invest heavily in this area? Therefore, the widespread use of bus-type instruments requires a long I replacement time. Moreover, compared with DCS, the functions are different, so there is no inevitable replacement problem! ! ! This post was last edited by Lianxiangxiyu on 2008-2-19 18:53 ]

Unjustly accused! ! How could I be wrong? I just said that it is impossible for FCS to replace DCS. It does not mean that FCS will not become the mainstream of control! FCS has its room for development, but it cannot replace DCS as the poster said! :$

It is impossible to quit DCS, it can only become easier and more convenient to use. After all, there are still only a few large-scale control systems in large enterprises, and DCS is easier to operate and use by engineering personnel.

Personally, I think the fieldbus is not yet complete and mature, and there are problems such as communication failure. In addition, fieldbus temperature instruments are currently very expensive. When will there be a broader application space after unifying FF and PROFIBUS?

The two things cannot be confused without conflict.