"Communication protocol" hands-on anatomy "environmental protection industry standard of the People's Republic of China (hj/t 212-2005): Data transmission standard of online automatic monitoring (monitoring) system for pollution sources"

Remember a few years ago, see the "Environmental protection industry standards of the People's Republic of China (hj/t 212-2005): The source of online automatic monitoring (monitoring) system data transmission standards" this agreement, at that time looked at the head is big, finally did not start to design support him. Until recently, the customer said: you VOC instrument good ah, if you can support the HJ212 transmission protocol ...

The mind appeared when reading that agreement when the tangled, and now actually have customers want me to support this troublesome agreement, no way, must do ah, perhaps made out or exclusive? Ha ha

To my surprise is this reading this transmission protocol standard, I incredibly easy to understand, I think this agreement is very simple, and write well, all-encompassing.

Write down here to provide some references for spectators.

"Overview" HJ/T 212 This Agreement, is to standardize the environmental Monitoring Center to read each enterprise's emissions data and a communication protocol, each manufacturer's sensors and instrumentation equipment to obtain data, through the support of this Protocol, to achieve real-time or sharing data transmission to the Environmental Monitoring Center, In this way, leaders can learn about the real-time emissions of pollutants from each company in the monitoring Center.

"Industry status" usually do instrumentation enterprises, most of them are implemented with single-chip microcomputer, so the instrument enterprise data is usually not directly passed to the EPA, and the development of support for this agreement, for single-chip microcomputer is almost impossible, even with the host computer may not be able to support, because the protocol is a bit complex and professional.

So there are some companies, specifically to do environmental data acquisition instrument, they will instrument data acquisition, and the EPA to establish 3G/4G network communications. So many environmental protection equipment engineering companies on the procurement of the corresponding instrument equipment and a number of instruments can be. For example, a VOC organic exhaust gas detection instrument, he output 4~20ma; a digital mining instrument, he has a 4~20ma collection, he collects the instrument's current signal, converted to digital; then dial and the EPA's Monitoring center link;

"Problem" This method is only suitable for fixed location data transmission, because the device is relatively large. But like VOC organic volatile organic emissions monitoring, not every enterprise is willing to spend tens of thousands of dollars to install a set, and after installation, there is a lot of maintenance later. At present, most of the VOC detector is PID optical ion sensor, this sensor needs a UV lamp has been irradiated, long time, it will decay or become dirty, can not detect the true concentration.

The use of handheld, 4 times a day to detect the discharge port is a more economical way, and some environmental law enforcement, health law enforcement, safety supervision and so on when using this instrument to detect, will face handheld instrument data storage and data upload problems. Because most of the instruments are designed with single-chip microcomputer, the data storage is very small, very simple. PV6001 is a smart-machine VOC instrument, stored once per second, but how can data be uploaded to the EPA? Plug-in to the computer is too cumbersome to export, and the Monitoring Center is unable to see the results of the instrument in real time.

"Solution" let PV6001 support data in real-time transmission to the EPA's monitoring center, the network using the 3G/4G module or via mobile WiFi hotspot.

1. We usually use the phone's WiFi hotspot better, because most people now have smartphones. If it is inconvenient, it is equipped with 3G/4G module.

2. The rest is to allow the VOC detector software to support the HJ/T 212 Transfer Protocol.

"WinCE Smart Machine faces 2 problems"

1. WiFi Network connection problem: Originally we used to call WinCE's WiFi link program, can actually find his UI has a bug.

2. How to implement the agreement.

"Developing your own Wi-Fi network Connection program"

Find Pudn and Cnblog, get some article help, designed their own WiFi link program.

1. Get the first WiFi card, the name of the network card is very important, in the future need to use him to get more information.

2. Get WiFi signal point name and signal strength via NIC.

3. Enter the WiFi name password, encryption method, whether it is hot, authorization method and so on several elements, add the configuration to the WiFi connection list.

Also need to design the function: Adjust the order of preferred network list, because there may be 2 WiFi at the same time, one can not surf the internet, then the trouble.

"HJ/T 212-2005 data Transfer Standard"

During the simple period, we support only: "Start uploading data in real time", "stop uploading data in real time", "upload data in real time", "Set upload Interval" waiting for 4 instructions.

"To be Continued" ....

"Communication protocol" hands-on anatomy "environmental protection industry standard of the People's Republic of China (hj/t 212-2005): Data transmission standard of online automatic monitoring (monitoring) system for pollution sources"