Chapter 1002 Pie in the sky

Gao Zhendong was even more confused than them. He thought about it and gave them a way out: "Ah, this type of dam is not widely used in China, so you don't have to worry about it for now."

"Ah, yes, yes, Mr. Gao is right, it is not much. But we have not kept up with our studies. Not using it much does not mean not using it. We still do not have a comprehensive grasp of hydraulic engineering knowledge."

Director Hou followed immediately and said, "The leader has even given you the step, why don't you come down quickly!"

However, the second half of his sentence was spoken sincerely. Compared with Chief Engineer Gao, the comrades on his side indeed did not study enough.

What about being too busy at work and having no time? That's all nonsense. No matter how busy you are, can you be busier than your leaders? They can handle your professional matters clearly, but you are clueless. This is the problem, this is the gap!

Director Hou's admiration for Gao Zhendong came from the bottom of his heart, without any flattery at all.

This kind of leader is still good. Even if you want to flatter him, you don’t have any psychological burden. You just need to repeat the facts.

However, Gao Zhendong still took the opportunity to explain to them the benefits of concrete face rockfill dams, and added: "It is rarely used now, probably because cement is relatively precious, and the machinery and technology are not yet mature. It is normal that you don't know."

Look, a leader is a leader, he even found a reason for you.

In the end, Xue Chongli and Gao Zhendong were both professionals and asked the most important question: "Mr. Gao...Mr. Gao, what do you use to transmit this data?"

As expected, he is a professional and asked the right questions.

"You asked the right question. This matter will probably fall on you. You need to make a remote collection and transmission device to collect this data and then transmit it to the host computer that uses the data through a unified channel. This host computer may be in the reservoir management office or in the administrative management agencies of reservoirs at all levels."

Anyway, as far as Gao Zhendong knew, before he traveled through time, almost all data on large-scale reservoirs had to be transmitted to at least one place - the flood control and drought relief offices at all levels. The affiliation of this department was transferred back and forth between the water conservancy department and the emergency department.

This department has an important daily task, which is to limit and direct the operating water levels of reservoirs within its jurisdiction in order to prevent the occurrence of floods and waterlogging disasters as much as possible. In theory, no matter whose reservoir it is, the operating water level cannot be higher than the operating water level issued by the Flood Control Office.

Of course, it is not uncommon for hydropower stations to ignore orders and privately raise operating water levels for economic benefits. In his previous life, Gao Zhendong often heard his elders talk about this as a joke.

Xue Chongli is Gao Zhendong's classmate. He is also a top university student from Wudaokou who has received professional education. He immediately got into work mode.

"This thing can be made with the single-chip microcomputer you made, so there should be no problem. There are ways to upload it, whether it is dialing up the modem telephone line or connecting the modem to the radio, it can be transmitted. The only problem is that the sensors below are varied and it is not easy to unify them."

In a few decades, data telemetry will have many channels, including radio, telephone lines, broadband, satellite, mobile communications, Lora, Zigbee, etc. However, at this time, for ordinary units, only the two he mentioned are reliable. Even for these, they have to be higher-level units, otherwise, without that dedicated line or that radio station, the data cannot be transmitted.

At this time, Xue Chongli also realized that the single-chip microcomputer was invented by Gao Zhendong. The "Gao Zhendong" mentioned in the computer-related reports he read in the newspaper was really his old classmate.

When I saw him before, I thought he was a person with the same name. Now it seems that he must be my classmate, otherwise there is no way to explain why he is in such a high position.

It’s just that this name of my classmate is really common. Not to mention computer science, I vaguely remember seeing this name in several reports that are not related to my major.

There is smoke coming out of the Gao family’s ancestral grave.

Gao Zhendong nodded. His old classmate's skills were indeed impeccable and he considered everything very comprehensively. Currently, there was no unified data transmission interface from sensor to collector.

He smiled and said, "You guys make one. If you do well, I will contact the 12th Ministry of Machinery to promote it in multiple industries across the country for you."

This type of data transmission interface can actually be shared by multiple industries, just like the modbus used by Gao Zhendong in his previous life.

What? Xue Chongli never expected that this would turn out to be a national-level task.
The task that seemed insignificant to Gao Zhendong was truly national-level in their eyes.

Before Xue Chongli could say anything, Director Hou followed him and said, "Hey, Comrade Chongli is indeed a great general and a lucky general. Not only does he have excellent technical skills, but he can also easily get national-level projects."

He could also see that this matter was not a big deal for Chief Engineer Gao, as he didn't even consider the process and just told his department to handle it. But for them, it was different. As long as they could get into the national team, it was better than anything else, and they could do anything.

"Oh, thank you so much for the strong support from Chief Engineer Gao. No problem, we will treat this matter as the highest level political task and make sure that not only our water conservancy department, but also other industries can use this advanced data transmission interface." Director Hou immediately raised the importance of the matter, and patted his chest with such force that it could break a stone.

It's no wonder that he is so active. The main reason is that there are not many projects and topics in the field of water conservancy automation these days. You have to grab every one you can get, not to mention that this one sounds like it has a national name in it.

Gao Zhendong laughed: "Not really, but this thing is indeed useful, so it's still meaningful to try it."

Gao Zhendong's laughter made Director Hou feel very happy.

Xue Chongli finally reacted: "Really? Zhendong, that's great. Let me thank you on behalf of our institute and our department."

I think the hospital must be very happy to have such a representative. It's simply pie in the sky!
Gao Zhendong nodded: "No, no, the work always needs people to do it. It's just right, I will capture your able-bodied men."

It would be no problem for you to capture strong men like this every day, Director Hou muttered to himself.

Xue Chongli was more realistic: "So how did you plan this interface?"

Gao Zhendong thought for a moment and said, "I say, remember this. I usually won't get involved in the specific work. If you have any difficulties, you can come to me."

"Make two interfaces, or rather, this set of interfaces includes two interfaces. One is analog and the other is digital. The analog one uses a 4~20mA current loop, which is readily available and I think you should be familiar with it. I won't say much about this, just copy the standard."

The 4~20mA current loop is one of the standard analog signals in industrial control. It has excellent performance and strong environmental adaptability. Even in the 21s, it is still widely used. Another commonly used one is 20~0V/5~0V, but the overall performance of the voltage signal is not as good as 10~4mA, and the conversion between the two is relatively simple, so Gao Zhendong is not going to bother with it any more.

Xue Chongli nodded repeatedly: "Okay, no problem."

If there is a ready-made one, use it. The old classmates have clear ideas. This can greatly reduce the research cost and speed up the time to achieve results. Moreover, the establishment of this interface only stipulates the electrical characteristics, parameters and process of the output and receiving parties. As long as both parties follow this standard, data transmission can be achieved. It is not necessary to make one or a set of devices to realize its function, which is faster.

Xue Chongli had a deep enough understanding of the 1950~4mA current loop that appeared in 20, and knew that it was very suitable to be used here.

Xue Chongli also knew that the difficulty of this matter might lie in the digital interface behind it.

As expected, Gao Zhendong's next sentence made things a bit difficult for him.

"As for the digital interface, it consists of two parts, the electrical interface and the transmission protocol. You can work on these two parts separately. Although they both belong here, they can still be used separately. Do you understand what I mean?"

Xue Chongli was a little confused at first, but he reacted quickly: "I understand what you mean. The electrical interface is responsible for the transmission of physical signals. In fact, other transmission protocols can run on it. The transmission protocol is responsible for specifying the specific transmission method and process. It can be used even on other similar electrical interfaces. Is that what you mean?"

Well, Gao Zhendong was very happy that his classmates could understand it clearly and learn it quickly.

"Yes, that's what I mean. We can kill two birds with one stone. Let's talk about the electrical interface first..."

Gao Zhendong had no choice. He told Xue Chongli the requirements of the RS-485 serial interface.

RS-485 is a serial interface that can realize bus structure and differential transmission. It is as famous as RS-232, RS-422 and other interfaces, but its actual application is even wider.

Although it can only work in simplex mode, the connection is simple and only requires two wires. In theory, it should be a twisted pair, but in practice, any wire will do for short distances. Moreover, the transmission distance of this interface can reach more than 1 km, and the anti-interference performance is also strong. The specific speed can be very high, which is related to the flip speed of the device itself, but at this time, 1200 baud rate or even higher is no problem at all.

This is probably sufficient for current industrial control needs.

Xue Chongli nodded frantically while listening. This thing is very useful. It seems that these characteristics and requirements are not difficult from an electronic point of view. For example, 2~6V for signal "1" and -2~-6V for logic "0" sound like they can be figured out on the spur of the moment. But the more he listened, the more wonderful it seemed. These electrical characteristics that don't sound very prominent have combined into a universal interface with a simple structure, low price, long transmission distance, low environmental requirements and strong anti-interference ability.

This thing is simply the gospel of automation and can be used for the transmission of most digital signals.

(End of this chapter)