Industrial IOT gateway is a data transmission device that fully supports mobile, Unicom and telecom 4G/3G/2G communication networks. 4G intelligent gateway accomplishes bidirectional, transparent and wireless transmission between serial devices and servers, and between serial devices and serial devices. IOT gateway has the features of simple application, USB/Bluetooth setup parameter, and long-distance maintenance, etc. It can be forwarded through cloud channel and protocol development kit, Through the cloud channel forwarding, protocol development kit, network to serial port tools, etc. can easily develop user monitoring software or docking third-party application channels.
Basic function
The so-called gateway is mainly responsible for the connection of two heterogeneous networks, which is especially common in industrial IoT scenarios, because the sensing network often uses completely different electrical signals and protocols from the common network layer (long-distance transmission network).
Sensing Layer Signal Interface
The primary task is to interface the signals of the devices within the sensing network. This module contains hardware interfaces for interfacing different electrical signals and also software for corresponding data collection and command sending. In order to cope with the complexity of the sensing layer, manufacturers of industrial gateways generally equip a combination of hardware interfaces and protocols for the signaling interfaces of the sensing layer according to their target application areas.
Network Layer Signal Interface
The primary task is to interface with the signals of the network layer. Compared with the perception layer signal interface, the network layer signal interface is generally much simpler, because generally only one standard long-distance transmission network and its protocols are required in the whole system, so the corresponding hardware interface and data transceiver software are relatively single. However, this does not mean that can only support a, in practice, industrial gateway manufacturers for product versatility is often designed to support a variety of long-distance transmission network method. Detailed method, can be a variety of interfaces at the same time equipment method, can also be the product design into a plug-in card can be equipped with the method, so that the user selects a different equipment in the factory at the time of equipment.
Data processing
The data processing of the equipment side of the primary processing is the data mismatch problem. That is to say, differences in the range, frequency, and completeness of the data demanded by the service side. The purpose of data processing is to organize the data coming in from the input interface, transform it into a data method suitable for output and push it to the output interface. The input and output sides here can be played by the device side or the service side, so the data activity is bi-directional and varies depending on the type of data.
On-site database
The processed data in some scenarios also need to be stored in the local database of the gateway, so as to be utilized for complex data processing or other local transaction logic processing. Because the industrial gateway is generally categorized as an embedded computing device, so such databases are generally selected embedded database. Embedded database function is more simple, generally have memory buffer to improve access speed.
Local Transaction Logic
It is mainly to deal with the transaction logic of the part of the system related to the devices, sensors and actuators connected to the part of the sensor network associated with the gateway. The richness and complexity of the local transaction logic module varies greatly from gateway to gateway. If an industrial gateway does not have this part of the function module, it is often called a data transmission gateway, or a protocol converter or communication processor. A detailed description of the local transaction logic can be found in "Marginal Accounting".
Other Functions
In addition to the above primary modules, a gateway is often equipped with a user interface for its functions, which can be in the form of keystrokes, command line (via telnet or serial port), or graphical interface (e.g., built-in WEBServer or even with a panel). If the gateway has a local transaction logic, perhaps also need to load the local transaction logic to its script files, equipment files required by the tool.
Another category and its important module is the security module. As with network equipment in general, security is an essential design consideration. In addition to defending against network intrusions from the outside, it is also important to consider the authentication of the device when it accesses the server side, that is, only legitimate devices can connect to the server side. This requires that each member of the device side (industrial gateway or smart device) must have a unique identification mark and authorization mark to enter the industrial Internet of things, otherwise there may be an impostor of the external miscreant device access, and then interfere with the normal operation of the entire system. Similarly, the device can only access the legitimate server, or it will be an illegal impersonation of the identity of the server to interfere with the normal operation of the device.
Industrial gateway as a long-distance device, its self-protection is also very important. It is generally required that it should utilize its own advantage of connecting to the server, and be able to automatically download its own software update package from the server and finish the update, and some settings and equipment operations should be able to be completed through the long-distance logon, and then reduce the cost of stationing personnel for on-site protection and improve the responsiveness to the user's needs.
Technical Completion
Industrial gateway generally adopts embedded architecture to complete. The system is equipped with the required interface hardware according to the type of electrical interface supported by the design. The processor may adopt special SoC, such as ARM, MIPS and other architectures, or it may be a general PC architecture of low-end Intel X86 CPU, and at the same time, it should also be equipped with the necessary amount of memory and storage devices, in order to support the accounting and save data and equipment parameters. Operating system is common for a variety of embedded operating systems, of which Linux is now more prevalent. As a communication processing equipment, the natural need to equip the necessary types of communication protocol analysis module. Communication protocol analysis according to the protocol and the characteristics of the operating system, perhaps the user state process, or perhaps the operating system kernel state process. Then it is the data processing module as the center of the whole gateway. The data processing module is mainly completed by the software and the main processor, but does not rule out the use of GPU and other co-processors in order to speed up in some scenarios. Transaction logic and embedded databases are optional, along with the necessary user interfaces and other applications. Security mechanisms should be properly represented at all levels.
In terms of programming language for the software part, C/C++ is generally preferred for this kind of embedded devices with low computing power but some real-time requirements, but this does not stop developers from using shell, java, Python and other high-grade languages in the gateway with enthusiasm. Because in the user equipment interface and other low-frequency operations, the use of these high-grade language development power is higher, and these low-frequency operations, even if the performance of the poor does not form the performance of the daily operation of the problem. In the field sensing layer due to the instability of the user's business process and have to follow the changes in the scene, the gateway also have to follow the changes in equipment and even the need for a certain field of secondary development, this high-grade language to provide rapid development capabilities may be more necessary!