Hollysys PLC - five characteristics that become a necessary condition for high-end PLC

Since the day of the birth of PLC, it has occupied the core position of the entire automatic control system. There are also many discussions about the development direction of PLC, whether it was predicted that PAC would replace PLC 10 years ago, or during this time, some people even said that PLC will no longer be needed in the future Industry 4.0 era.

So what kind of PLC do we need for the current transition period when the world is vigorously deploying intelligent manufacturing? In particular, what are the characteristics of medium and large PLCs, which are known as the "crown jewels"?

First of all, one thing needs to be clear, the high-end PLC we talk about now is not the same as 10 years ago or even 5 years ago. It's not that it was a high-end PLC 10 years ago, but now it can still be called a high-end PLC. Because society is developing, more advanced things have come out, and the so-called high-end, the criteria for judging it are different in different periods.

Hollysys PLC - five characteristics that become a necessary condition for high-end PLC

In the current era of intelligent manufacturing, the following five characteristics have become a necessary condition for high-end PLC:

1. The ability to bring points is no longer the key, but the ability to communicate is more important

Now everyone sees that the control system architecture has been fully industrial Ethernet. When the fieldbus rose more than ten years ago, we said that a high-end PLC should have distributed control capabilities, be able to bring many distributed sites, and have the connection ability of fieldbuses. At that time, the performance index of a controller was evaluated with point capability as the most important one. With the improvement of the intelligence of field equipment and the need to ensure the reliability, stability and availability of the control system, the ability of the CPU to carry points is no longer the key to distinguish between high-end and non-high-end, and now the focus should be on the coverage ability of Ethernet communication in the field, which directly determines the control level of the system over the field process equipment. At the same time, because we are now in a period of connecting the previous and the next, for example, the fieldbus is still in use, it cannot be said that because it has been upgraded, it is no longer compatible with the past fieldbus. However, the future development trend is the world of Ethernet, and the support for Ethernet should be more important, and the compatibility with existing fieldbus protocols is also an aspect that cannot be ignored.

In the past, Ethernet was a means of communication between PLC and upper management machine software, and its advantage was that it could transmit a larger amount of data, and more control stations could be connected to this network. However, for on-site control, even if there are more on-site I/O stations and more equipment, in fact, its communication volume is not so large, and it will not be as large as the communication between PLC and host computer. However, it has higher requirements for real-time performance and reliability, and packet loss rate is important, and real-time and data transmission verifiability are very important.

Now, with the development of lean factory management, more and more factories have begun to use high-level operation and maintenance management software such as MES system and asset management system, of course, some people call it intelligent manufacturing or digital factory. This is due to the fact that more and more process customers have begun to pursue lean control, and they hope to take some on-site data through the PLC system to use it directly to improve efficiency and real-time, so as to improve the efficiency of the overall operation and management capabilities.

For full Ethernetization, both PLC manufacturers and users have reached a consensus. It is also well confirmed on Schneider's release of Quantum+.

2. The information security of PLC has become indispensable

In the case of "one network to the end", there is a problem involved: after the network is connected, the on-site production process equipment and the management software on it are even connected to the cloud, it opens up some management and data analysis systems and the special system channel of our industrial control, so its information security guarantee requirements are higher. Once the data is exchanged from the field device, it means that the entire communication network is opened, and if there is a problem with information security at any node in the process of opening up, it may cause mutual impact. If the upper-layer software information security is not done well, it may invade from this place and then continue, if the local information security deployment between the control network and the management network is not done, it may be from the above or below the intrusion, which will cause a series of chains.

Then the PLC side also needs to do a good job of information security. In the past, PLC did not do any consideration in the information security part of the research and development, because the mainstream high-end PLC was developed 20 years ago, and there was no information security at that time. But this treats the symptoms but not the root cause, just like people, you are very weak, you are sick, you take tonic medicine every day, you seem to be better, but once there is a new problem, you can't resist it. Defense-in-depth can play the role of layer upon layer of isolation and protection, but the real security still needs to be done at each control level itself, which is also a big problem, the new generation of high-end controllers must be considered, starting with themselves, no matter whether you are deployed elsewhere or not, at least the PLC itself should not be infringed, and it has the security protection ability of the ontology.

3. It is no longer a simple pursuit of how fast it is, but how stable and reliable it is

After the production process entered the industrial age in the past, it has gradually matured, and it is very difficult for us to change a process now, because we have basically changed what can be changed, that is, it is difficult to have a big change in the processing speed of the control system in the process. For the efficiency or refinement of the process that users are most concerned about, in fact, it can be optimized from two aspects, one is its entire production process management, and the refined management of the entire material. The other is the refined management of equipment.

But in this area, in fact, under the control of the ability of the previous generation of high-end controllers in the past 20 years, our equipment has no problem with its processing speed, which can fully meet the needs of the process, and the faster control system is difficult to reflect the value of improving and enhancing the operational benefits of the plant. Just like running on the highway, it doesn't make sense for you to run to 500 miles, because for stability and reliability, we can make a car that can run more than 200 miles to meet expectations, which is enough, no matter how fast you are, you can't use it, but it brings potential harm. In this case, it no longer makes sense for us to blindly pursue how fast we are with a high-end processor as in the past. But one thing is the same as before, it's stable and reliable, like why should I drive a car instead of riding a motorcycle? After all, it is safe and reliable.

High-end controllers now, not to see how many points can be brought, how fast the processing speed is, because these development to the previous generation is no longer a thing, now just take a small and medium-sized controller, said that the ability and processing speed to reach the level of large controllers are not much different. But the core thing is its security, stability and reliability, and its system communication ability, because in the past, large PLC was mainly a large system, and the large system must have communication with each other, collaborative management capabilities, and the ability to communicate with the host computer, support capabilities, these capabilities are to judge whether the system is a high-end control system, or a small and medium-sized control system.

4. The trend is to reduce the size and ease of use

In the past, we said that it was good to be big, but in the past, there was no way, because it was not small at that time, but in fact, it was made as small as possible. Electronic products must be under the same performance, the smaller it is, the higher its technical content. In addition, we know that there is a big trend now, because industrial products are more and more accepted by everyone, and they have begun to move towards the civilian field, especially after the industrial development of various countries to a certain extent in recent years, there are a large number of livelihood projects, such as many large buildings have begun to use PLC in the control, in the past are embedded controllers, but its versatility and expansion ability are limited, and the maintenance needs professional people to maintain, and PLC has various reasons to make it popular began to reflect.

In the future, the distributed requirements are getting wider and wider, even in the past these traditional heavy industries, it has higher and higher requirements for the distributed installation of the control system, in the past, we have a special control station, especially in the traditional industry, all PLCs are placed in a main control station. However, there is a problem, when these modules are connected to field devices, there are many connection wiring, complex construction, complex maintenance, and high cost, so there are distributed I/O.

In the future, all equipment will develop towards intelligence. In the future, the motor on the site, some of the detection instruments on the site, may be Ethernet interface, it is directly connected to the control system through Ethernet, the main control room may be a cabinet full of controllers, and then a bunch of switches connected to a bunch of network cables. In this case, do you think the PLC should be bigger, or smaller? The control concept has changed, the design of the factory will also change, and the screen of the monitoring system will be large in the future, but the equipment should be used in a small place as much as possible to improve comfort and efficiency. If you think about it this way, if you control one 3,000 points now, you need ten cabinets, and it will become more and more impossible in the future.

How to put the original high-end chip on the smaller circuit board, or integrate the chip with more powerful functions than the original into a smaller circuit board, which requires professional design and manufacturing capabilities, not everyone can do very small, the electronic control system is easy to make bigger, and it is more difficult to make it smaller, because the smaller size solves the EMC interference, solves the heat dissipation problem, and solves the problem of circuit layout, so as to achieve a more powerful controller than the original, which is a manifestation of the high-end.

5. Experience inheritance and professional quality are essential

High-end controller does not mean that a product can be realized one day, it is different from civilian equipment, it can be said that I used to make a monitor, a computer, suddenly came out of me to make a mobile phone, it quickly became the core player of the industry. However, the field of industrial control does not have this condition, because the mobile phone is broken, a problem will not affect the big thing, the user's attention to the stable operation is not like industrial equipment, if the on-site control stops, a little problem, it is a big deal, so the inheritance is particularly important.

Why are there so many PLC manufacturers, only a few can provide high-end controllers, not everyone can do it, is because of the inheritance of experience. You have no experience, suddenly come in, just like engaging in software and suddenly find a few masters to come over and compile it, it's not like that, it involves all the chips, all the layout, EMC anti-interference, all aspects are a summary of experience, through how many years of continuous accumulation, continuous optimization, and then optimization to do.

The other one is professionalism, why should there be professional quality? Nowadays, there are many people who can make controllers, especially if they are made with chips such as PC-base, which are ready-made chips and operating systems. In the current PLC industry, its standards, whether it is programming standards or system architecture, have standards to follow. In the case that there is something to follow, it is very easy to make an imitation of something, but the imitation of something, its professionalism is very important, no experience accumulation, no professional domain knowledge, it is difficult to make a very professional thing, which is also a lot of manufacturers can only do low-end controllers. The more you go to the high-end, the more difficult it is, that's why many companies have been doing it for so many years and want to rush to the high-end, but they haven't been able to rush up, that's the problem.

Hollysys PLC - five characteristics that become a necessary condition for high-end PLC

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