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The advantage of using wireless data transmission module... Data transmission can be simply divided into two major types: wired (including the installation of optical cables, cables or leased telecommunication lines) and wireless (including the establishment of dedicated wireless data transmission system or the borrowing of CDPD, GSM, CDMA and other public network information platforms).     In...

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Industrial-grade 4G router TCP/IP network architecture 1. Layering of TCP/IP network system   TCP/IP (TransmissionControlProtocol/InternetProtocol), transmission control protocol/Internet protocol. It was developed by the defense advanced research projects agency in the 1970s, and was later integrated into UNIX and popularized. It emerged in the 1980s as the Internet's...

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The structure of 4G DTU The main function of DTU is to transmit data from remote devices back to the background center via wired/wireless. Different data transmission modes of DTU include all-network-connected DTU, GPRS DTU, WIFI DTU, CAN DTU and 4G DTU. Today, we will have a look at the structure and work flow of DTU.   To complete...

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What are the wireless connection technologies of the... Internet of things (iot) applications have been deeply rooted in our lives. The E-Lins H685 industrial-grade router is a small industrial-grade wireless router with single or double LAN ports. TDD/ fdd-lte, 4G, 3G, GPRS network optional. Besides, what are the wireless connectivity technologies for the Internet of things?   1....

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The use of industrial wireless routers Industrial-grade wireless router adopts high performance 32-bit industrial-grade ARM9 communication processor, which is widely used in finance, electric power, postal, water conservancy, environmental protection, meteorology and other industries.   Industrial router is mainly used in intelligent transportation,...

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The advantage of using wireless data transmission module in industrial control system

Category : 产品文章

Data transmission can be simply divided into two major types: wired (including the installation of optical cables, cables or leased telecommunication lines) and wireless (including the establishment of dedicated wireless data transmission system or the borrowing of CDPD, GSM, CDMA and other public network information platforms).

 

 

In comparison, the wireless data transmission mode with wireless data transmission module has the following advantages over other modes. The following describes the advantages of the wireless data transmission mode with wireless data transmission module compared with the wired communication mode.

 

 

1. Wireless communication is cheap

 

The establishment of wired communication means must erect cables or excavate cable trenches, which requires a lot of manpower and material resources. The use of wireless data stations to establish a dedicated wireless data transmission mode does not require the erection of cables or trenching, but only the connection of wireless data stations at each terminal and the erection of antennas at the appropriate height. Compared with the wireless data transmission module to establish a dedicated wireless data transmission mode, saving manpower and material resources, investment is quite economical.

 

 

Of course, in some short-range data communication systems, wireless communication is no cheaper than wired, but sometimes the actual field environment is difficult to wire, customers will choose wireless communication according to the needs of the field environment.

 

 

2. The construction period of wireless communication is short

 

When within a few kilometers to tens of kilometers distance to a remote site connection communication each other, with the method of cable, must set up a long cable long in cable trench, or mining may need several months the project cycle time, and with digital module build special-purpose wireless data transmission way, only need to set up appropriate height of antenna, the project cycle, only need a few days or weeks can, by contrast, can quickly establish a wireless way communication link, shorten the project cycle.

 

 

3. Good adaptability of wireless communication

 

Limitations of wired communication is too large, in case of some special applications, such as mountains, lakes, forests and other special geographical environment and the application of moving object, such as wiring difficult environment, to the wired network wiring project has extremely strong further reading.in, wireless data transmission module and establishing special will not be restricted by the wireless data transmission mode, so in wireless data transmission module build special-purpose wireless data transmission way to more extensive adaptability than the wired communications have better, almost without being limited by the geographical environment.

 

 

4. Good scalability of wireless communication

 

After users set up a communication network, new devices are often added for the needs of the system. If adopt the way of the cable, need to wiring, construction more troublesome, but also could undermine the original communications lines, but if the special set up by adopting the wireless digital radio wireless data transmission way, just put the new devices connected to wireless digital radio can realize the system expansion, in contrast with better extensibility.

 

 

5. Wireless communication equipment maintenance is easier to achieve

 

The maintenance of wired communication link requires the inspection along the line. In case of failure, it is difficult to find out the fault point in time. However, the establishment of dedicated wireless data transmission mode by adopting wireless data transmission module only requires the maintenance of data transmission module.

 

E-Lins mobile data products covers 4G/3G/2G/WiFi routers, modems, CPE, and other data transmission devices, which are widely used in more than 150 countries and regions, and more than twenty industrial fields, such as power control, water schedule, traffic, oil field, weather forecast, environmental protection, street lamp control, post, bank, CCTV, security surveillance, and many other areas.

As Industrial grade router, the E-Lins H685 series 4G router with Ethernet is a compact, ruggedized 3G/4G/LTE cellular networking solution designed for mission-critical connectivity in the most challenging environments. It is qualified for M2M (Machine to Machine), IoT (Internet of Things) and In-Vehicle applications. Super mini size suitable for embedding applications.

In addition to the robustness, reliability, security, friendly-using, the H685 4G router with Ethernet is competent to be engineered to protect against extreme temperatures, humidity, shocks, vibrations, dust, reverse polarity, and transient voltage, which is widely used in more than twenty industrial fields, such as CCTV security surveillance, AMR, vehicle, retails, vending machines, power control, water schedule, traffic, oil field, weather forecast, environmental protection, street lamp control, post, bank and many other fields.

Highlight of H685 Mini size router:

Multi-carrier 2G/3G/4G LTE support with SIM card slot

Cellular/WAN RJ45/WiFi client failover

Supports LTE Advanced with SIM-based auto-carrier selection

Cloud-managed (with NMS network management system), TR-069, Web management, SMS, SSH/Telnet/Command, SNMP

WiFi (802.11 a/b/g/n, 2.4Ghz)

Certified 3G/4G/LTE enterprise/industrial grade internal modems

Built-in transient and reverse polarity voltage protection, over-current and over-voltage protection;

5-40V DC voltage input range (5-60V DC option), Dual Power Inputs / Power Failover;

POE (Power over Ethernet)

GPS / GNSS support

Serial Port

DI/DO port * 4

Supports Ethernet (T1, DSL, Cable, MetroE), WiFi as WAN, and Metro WiFi

Ruggedized to ensure always-on connectivity

Create real-time alerts to monitor uptime

Offer secure, guest WiFi to passengers

Advanced security, VPN, and stateful firewall to protect sensitive data

Robust Metal Case is ruggedized for vibration, shock

Desktop, Wall-mount and Din-rail mount of installation

External antenna connectors for high gain antennas replacement

The structure of 4G DTU

Category : 技术相关

The main function of DTU is to transmit data from remote devices back to the background center via wired/wireless. Different data transmission modes of DTU include all-network-connected DTU, GPRS DTU, WIFI DTU, CAN DTU and 4G DTU. Today, we will have a look at the structure and work flow of DTU.

 

To complete the data transmission needs to establish a complete data transmission system. In this system includes: DTU, customer equipment, mobile network, background center. On the front end, DTU is connected to the customer’s device via a 232 or 485 interface. Therefore, DTU alone cannot complete the wireless transmission of data, and it needs to be used together with background software. After establishing the connection, the front-end equipment and the back-end center can conduct wireless data transmission through DTU, and the transmission is two-way. The new generation of DTU has developed to varying degrees in terms of simple data collection, multimedia display and data processing.

 

GPRS DTU communication

 

GPRS DTU working process:

After GPRS DTU is powered on, it first reads the working parameters saved in internal FLASH (including GPRS dialing parameters, serial port baud rate, data center IP address, etc., which have been configured in advance).

 

GPRS DTU logs on to GSM network and then does the GPRS PPP dialing. Upon successful dialing, GPRS DTU receives an internal IP address (typically 10.x.x.x) randomly assigned by the mobile. That is, GPRS DTU is in a mobile Intranet, and its Intranet IP address is usually not fixed and changes with each dial. We can understand that GPRS DTU is a mobile internal LAN device, through the mobile gateway to achieve communication with the external Internet public network. This is similar to how a computer in a LAN accesses an external network through a gateway.

 

GPRS DTU initiatively initiates the communication connection with the data center and maintains the communication connection. Because GPRS DTU is in the mobile Intranet, and the IP address is not fixed. Therefore, only GPRS DTU can actively connect to the data center, and not the data center can actively connect to GPRS DTU. This requires the data center to have a fixed public network IP address or a fixed domain name. The public network IP address or fixed domain name of the data center is stored as a parameter in GPRS DTU, so that once GPRS DTU is powered up and successfully dialed, it can be actively connected to the data center.

 

Specifically, GPRS DTU initiates TCP or UDP communication requests to the data center through parameters such as the IP address of the data center (if the domain name of the data center is adopted, the IP address of the data center will be resolved through the domain name of the data center) and port number. Upon receiving the response from the center, GPRS DTU is deemed to have successfully shaken hands with the center, and then the communication connection is maintained. If the communication connection is interrupted, GPRS DTU will immediately shake hands with the center again.

Now that the TCP/UDP communication connection has been established, data two-way communication is possible.

 

GPRS DTU application

 

Wide application of DTU:

DTU has been widely used in electric power, environmental protection, LED information release, logistics, hydrology, meteorology and other industries. Although the application industry is different, but the principle of the application is the same. Most of them are connected with industrial equipment, such as PLC, SCM and other automation products, and then establish wireless communication connection with the background. Today, with the development of the Internet, DTU is more and more widely used. It provides help for the information and industrial integration among various industries. It has also gradually developed into the core technology of iot application.

What are the wireless connection technologies of the IoT

Category : 技术相关

Internet of things (iot) applications have been deeply rooted in our lives. The E-Lins H685 industrial-grade router is a small industrial-grade wireless router with single or double LAN ports. TDD/ fdd-lte, 4G, 3G, GPRS network optional. Besides, what are the wireless connectivity technologies for the Internet of things?

 

1. Ethernet

 

Ethernet is a LAN communication technology. The IEEE 802.3 standard, organized by the IEEE, establishes the technical standard for Ethernet. It specifies the content of the protocol including the connection of the physical layer, the electronic signal and the media access layer. Ethernet USES twisted pair cables as the transmission medium, which can cover up to 200 meters without relaying. The most popular Ethernet types have data transfer rates of 100Mb/s, while newer standards support rates of 1KMb/s and 10KMb/s.

 

The biggest advantage of Ethernet technology is that it is the most commonly used LAN technology and has gradually replaced other LAN standards such as token ring, FDDI and ARCNET. Now we are familiar with the Internet is all these large and small LAN connected together, the formation of a global network.

 

2. Serial communication technology

 

Serial port is a very generic interface for communication between devices and is also widely used for communication between devices and instrumentation. Common serial ports are rs-232 (using 25-pin or 9-pin connectors) and semi-duplex rs-485 and full-duplex rs-422 for industrial computer applications.

 

Serial communication USES serial mode for communication, that is, the serial port sends and receives byte sequences by bit. Typically, the serial port is used for the transmission of ASCII characters. Serial communication USES three wires: ground wire, sending and receiving. The serial communication can use the sending line to send data and the receiving line to receive data at the same time.

 

(1) Advantages

 

The biggest is a bit high penetration rate of serial communication, serial port to a PC or a standard, usually in order to convenient to connect printers, most of the industrial equipment has a serial port, who do not have a serial port devices, in its development, the common method is developed through a serial port to connect to the computer, so a serial port equipment is most simple and easy way to communicate.

 

It is also worth mentioning that the cost of serial communication is very low if the cable connecting the serial port is not considered.

 

(2) Disadvantages

 

The networking ability of serial port communication is poor. Although it is usually more stable than wireless, it is also vulnerable to the electromagnetic influence of the environment in which the cable is located in the industrial environment, resulting in unstable communication or even burnt out serial port. Serial Ethernet is still a long way off, and is generally only suitable for low speed and small data volumes.

 

3. Modbus

 

Unlike the previous communication technologies, Modbus is generally regarded as an application-layer protocol standard for serial communication, and does not include electrical specifications. Modbus was originally published by Modicon in 1979 for the use of programmable logic controller (PLC) communication. Later, three modes of Modbus RTU, Modbus ASCII and Modbus TCP were derived. The first two physical interfaces are the serial ports described above, and the latter one USES the Ethernet interface.

 

With the extensive application of PLC in the industrial field, Modbus has also become the most popular communication protocol in the industrial field. It adopts Master/Slave communication mode, namely one-to-many connection. One Master controller can support up to 247 Slave controllers.

 

(1) Advantages

 

The main advantages of Modbus are:

Standardization, open, free use, no license fee, no intellectual property authorization.

Supports a variety of electrical interfaces, such as serial and Ethernet interfaces, and a variety of transmission media, such as twisted pair, optical fiber, wireless, and so on.

 

The frame format of Modbus protocol is simple, compact and easy to understand. Easy to develop, easy to use.

 

(2) Disadvantages

Modbus mainly has the following problems:

Poor networking capability, only master – slave communication

Network size is limited by the number of slave controllers with poor security, no authentication and no permission management, plaintext transmission is very risky in an uncontrolled environment

 

4. GPRS

 

GPRS stands for General Packet Radio Service. GPRS is a long communication technology between a terminal and a communications base station.

 

Radio services first adopted analog communication technology, which became the first generation of Mobile communication technology, and later adopted digital communication technology, known as the second generation of Mobile communication technology. Among them, Global System for Mobile Communications (GSM) is the most widely used and most successful. GSM is designed primarily for the transmission of voice, voice in transmission, exclusive a channel.

 

GPRS can be said to be a continuation of GSM. It transmits data in packet mode and does not monopolize channels. Therefore, idle channel resources on GSM can be better utilized. The transmission rate of GPRS can reach 56~114Kbps. Using this data service, users can connect to the communication base station of the telecom operator, and then connect to the Internet to obtain Internet information. Launched by the European telecommunications standards commission (ETSI), GPRS was handed over to the 3rd Generation Partnership Project, or 3GPP.

 

(1) Advantages

 

Because the coverage of GSM network signal is very wide, in fact, the area where GPRS service can be used is also very wide, which is the main advantage of GPRS technology.

 

Secondly, the GPRS terminal can roam freely within the signal coverage, and the developer does not need to develop any other communication equipment (the operator is responsible for it), which is convenient for users.

 

Finally, due to the popularity of mobile communication terminals, their costs have been greatly reduced. Therefore, the adoption of GPRS communication technology in the Internet of things has a greater advantage over Wi-Fi or ZigBee in hardware cost.

 

(2) Disadvantages

 

GPRS terminals use the infrastructure of telecom operators when communicating, so they have to pay a certain fee, namely data traffic fee, which limits a large number of devices to connect to the network.

 

The lower rate of GPRS is another problem.

GPRS communication quality is greatly affected by signal strength, and the communication effect is poor in areas without signal coverage or weak, which may affect the completion of service.

 

5. NFC

Near field communication Near field communication NFC is a short-range high-frequency radio technology, which belongs to the RFID technology. Its working frequency is 13.56MHz and its effective working distance is within 20cm. The transmission speed is 106Kb/s, 212Kb/s or 424Kb/s. Data is read and exchanged through card reader and point-to-point business model.

 

NFC was first developed in 2002 by Philips semiconductor, Nokia and SONY. In 2004, NFC BBS was established, dedicated to the standardization and promotion of near-field communication technology.

 

(1)     Advantages

 

NFC communication distance is very short, but the communication confidentiality is good.

 

NFC card no power consumption, card reader power consumption is low, can be applied to a lot of no power consumption, or low power application scenarios.

 

The cost of NFC solutions is low, especially the cost of NFC CARDS is very low, especially suitable for covering a large number of non-intelligent objects.

 

NFC communication technology is currently widely used in mobile payment and consumer electronics. For example, many mobile phones already support NFC applications, and micropayment systems such as bus CARDS all use NFC technology.

 

(2) Disadvantages

 

The NFC does not carry the risk of eavesdropping on the wireless signals of other wireless communications, but the simplicity of its NFC card and the design of its passive response are also factors of insecurity. The risk of seeing reports: that the transaction information in an NFC card, for example, could easily be read by other card readers, or even a smartphone.

 

In addition, short communication distance and low communication rate are also its disadvantages, which limit the NFC to be only suitable for certain iot applications.

 

6. LoRa

 

LoRa comes from the word Long Range, which is a communication technology for long-distance communication. LoRa technology, based on linear Chirp spread spectrum modulation, continues the low-power characteristics of FSK modulation, but greatly increases the communication range. Chirp spread spectrum modulation has long distance transmission and good anti-interference performance, and has been used in military and aerospace communications for many years. In extreme cases, LoRa’s single gateway or base station can cover an entire city or tens of kilometers.

 

(1) application scenarios of LoRa

 

Typical scenarios for LoRa applications include very long battery life (a few years), long-distance communication between nodes, and low rates (such as just a few data transfers per hour). As with NB-iot, low power metrics can be sacrificed to increase speed.

 

The use of industrial wireless routers

Category : 其他

Industrial-grade wireless router adopts high performance 32-bit industrial-grade ARM9 communication processor, which is widely used in finance, electric power, postal, water conservancy, environmental protection, meteorology and other industries.

 

Industrial router is mainly used in intelligent transportation, environmental monitoring, security monitoring, security, wireless mobile detection, industrial data transmission, the financial industry, power industry, water conservancy industry, etc., support – 30 ℃ + 75 ℃ temperature, wide application. And civil routing is mainly family indoor use, so the adaptability to environment requirement is not high, the temperature only for 0 ~ 55 ℃.

 

The industrial router adopts rugged industrial appearance design, IP30 protection, built-in high-performance industrial-grade 32-bit communication processor wireless module, with embedded real-time operating system as the software support platform, and can be connected to serial devices, Ethernet devices or WIFI devices at the same time.

 

Support APN/VPDN private network, at the same time the device has IPSEC, PPTP, L2TP, GRE, OPENVPN VPN connection, with VPN client, server and other functions. Civil route even some do not have firewall, data security is low.

 

Why are industrial-grade routers so popular

 

In the industrial environment, due to the increasing demand for transmission speed and data volume, industrial-grade products are widely used to ensure more high-speed and smooth data exchange. After careful analysis of today’s connector supply market, shenzhen e-lins is an M2M wireless communication backbone enterprise, which mainly provides: industrial wireless router, wireless data terminal,GPRS DTU,CDMA DTU,3G router,4G router, etc.

 

Manufacturers are struggling to resist the onslaught of wireless technology. Wireless technology is now used in PCS and communications devices, and is favored in industry, medicine and automobiles. Wi-fi and bluetooth are popular; Wireless USB, ZigBee and RFID are gaining momentum, especially in consumer electronics, PC and communications.

 

The strong growth of the global mobile Internet device market, which is forecast to grow at a compound annual rate of up to 167 per cent over the next five years, will spur further adoption of wi-fi, bluetooth and ultra-broadband.

 

Despite the impact of wireless technology, PLC, industrial router, switch, DTU equipment and RTU equipment are still the trend of the future.

 

Industrial-grade wireless routers

 

As an industrial-grade router, the industrial-grade 4G router is more powerful than the ordinary household router in many aspects. Generally speaking, the well-known industrial-grade 4G router has the following advantages in the use process.

 

1. High stability

 

One of the major advantages of industrial-grade 4G routers is their high stability in data transmission and reception. It USES high performance industrial-grade wireless modules and industrial-grade high stability and high precision components, so that it can resist outdoor harsh environment without data transmission interruption or loss.

 

2. Fast data transmission and processing

 

Compared with ordinary routers, industrial-grade 4G routers use high-performance CPU processors, so they can transmit and process data several times faster than ordinary routers. They can satisfy more people to connect to the network at the same time, and the transmission distance is longer and the coverage is larger.

 

3. Powerful functions

 

Advanced industrial-grade 4G routers have more powerful functions than ordinary routers. For the average home router, the function is simple as long as it can connect to the network normally. But for industrial control industry, routers need more functions to run normally. Industrial-grade 4G routers have corresponding functions to meet the needs of different fields. If other special functions are needed, you can also choose customized products.

 

The main advantages of the industrial-grade 4G router are its high stability, fast data processing speed and powerful functions. In addition, the number of ports it provides and the strong wireless signal receiving ability are also its own advantages. Because industrial-grade 4G routers are often used in high-end fields or in complex outdoor conditions, they must have more functions and advantages to meet people’s needs.

Cascade and stack of industrial-grade 4G routers

Category : 技术相关

The most basic star Ethernet architecture, the actual star enterprise network may be much more complex than this. This renaturation is not only reflected in how high-end network equipment, how complex configuration, more importantly, the performance of network switching level is more complex. Industrial routers and firewalls in enterprise networks typically require only one, but industrial 4G routers are usually more than one (except for small networks with around 20 users). If you have a large number of users, say hundreds or even thousands, you will have to rely on cascading or stack extension connections from industrial-grade routers.

 

But cascading and stack technologies are also different, and their scope of application is different. Industrial 4G router cascade refers to the expansion of the whole network router and the whole network connection router through switching ports, which not only solves the problem of insufficient port number of a single industrial LTE router, but also solves the connection between the client and network equipment far away from the computer room. Because single-segment switched double-stranded Ethernet cables can reach 100 meters, each cascade of industrial-grade LTE routers can extend the distance by 100 meters.

 

However, this does not mean that it can be arbitrarily cascade, because the line is too long, on the one hand, the attenuation of the signal on the line is more, on the other hand, after all, the lower the level of industrial network router or sharing a port available bandwidth of the superior switch, the more the level, the lower the available bandwidth of the final client will be (although you may be using a 100-megabyte industrial network router), which has a great impact on the network connection performance, so from a practical point of view, it is recommended to deploy the industrial router of the whole network at most, that is, the core industrial router – second level industrial router – third level all-network router.

 

The level 3 here does not mean that only three industrial level full netcom routers can be allowed, but only three levels from the level. The ports used for hierarchical connection can be specialized UpLink ports or ordinary switching ports. Some full-netcom industrial routers have dedicated cascading (UpLink) ports, but some don’t. If there is a specialized cascading port, it is best used because its bandwidth is usually wider than that of a normal switching port, further ensuring the bandwidth of a lower-level, all-network-enabled, industrial-grade router. If not, it can only be cascaded through normal switching ports.

Characteristics and differences between RS485 and RS232

Category : 技术相关

RS232 and RS485 have always been the weak current common interface, but there are a lot of people do not understand the difference between them is not very thorough.

 

I. overview of RS485

 

RS-485 serial bus is widely used when the communication distance is tens of meters to thousands of meters. RS-485 adopts balanced transmission and differential reception, so it has the ability to suppress common mode interference. In addition, the bus transceiver has high sensitivity and can detect voltage as low as 200mV, so the transmission signal can be recovered from kilometers away.

 

The RS-485 operates in a semi-duplex mode, with only one point in the sending state at any time. Therefore, the sending circuit must be controlled by the enabling signal.

 

II. Features of RS485

 

The RS-485 is very convenient for multipoint interconnection and eliminates many signal lines. The RS-485 enables networking to form a distributed system that allows up to 32 parallel drivers and 32 receivers. In view of the shortcomings of RS-232-C, the new standard RS-485 has the following characteristics:

(1) the electrical characteristics of RS – 485: The voltage difference between the two lines ( +6V ~ +2V) represent the logic “1″, the voltage difference between the two lines (-6V ~ -2V) represent logic “0″. The interface signal level is lower than RS-232-C, so it is not easy to damage the interface circuit chip, and the level is compatible with TTL level, making it easy to connect with TTL circuit.

 

(2) The maximum data transmission rate is 10Mbps

 

(3) RS-485 interface adopts the combination of balanced driver and differential receiver, and has strong anti-common mode interference ability, that is, good anti-noise performance.

 

(4) The maximum transmission distance standard value of RS-485 interface is 4000 feet(about 1219meters), which can reach 3000 meters in fact.

 

(5) RS-232-C interface is only allowed to connect to one transceiver on the bus, that is, single station capability; The RS-485 interface is only allowed to connect up to 128 transceivers on the bus, that is, it has multi-station capability, so that users can use a single RS-485 interface to easily establish the device network.

 

III. Overview of RS232

 

The RS-232 interface conforms to the interface standard for serial data communication formulated by EIA. The original number is EIA- RS-232 (short for 232, RS232). It is widely used in computer serial interface peripheral connection. Connect cables and mechanical, electrical characteristics, signal functions and transmission processes.

 

The RS-232-C standard specifies data transfer rates of 50, 75, 100, 150, 300, 600, 1200, 2400, 4800, 9600, 19200 baud per second.

 

IV. Features of RS232

 

RS-232 is one of the main serial communication interfaces. Due to the early appearance of RS232 interface standard, it is inevitable that there are some deficiencies, mainly including the following four points:

 

(1) The interface signal level value is high, easy to damage the interface circuit chip. RS232 interface any signal line voltage is negative logic. That is, logic “1″ is -3 — -15v; Logic “0″ : +3 — +15V, noise tolerance is 2V. That is, the receiver is required to recognize the signal higher than +3V as the logical “0″, and the signal lower than -3v as the logical “1″. TTL level of 5V is the logical positive and 0 is the logical negative. It is not compatible with TTL level, so it needs to use level conversion circuit to connect with TTL circuit.

 

(2) The transmission rate is low, and the bit rate is 20Kbps in asynchronous transmission; Therefore, in 51CPLD development board, the comprehensive program baud rate can only be used 19200, which is also the reason.

 

(3) The interface USES a signal line and a signal return line to form a common ground transmission form, which is easy to generate common mode interference, so the anti-noise interference is weak.

 

(4) The transmission distance is limited. The standard value of the maximum transmission distance is 50 feet, which can only be used for about 15 meters in fact.

 

V. Application field

 

RS-232 is now commonly used in short distance transmission data rate is low, can work effectively in a noisy environment, such as factories, public site, etc., the commonly used equipment has a low-speed modem, industrial control equipment, programmable logic controller (PLC), computer numerical control (CNC) machine tools, robots, embedded control computer, medical instrument and equipment, and embedded controller development system.

 

RS-485 is commonly used in long-distance transmission with high data transmission rate. The commonly used equipment includes point-of-sale terminals (POS), measuring instruments and large specialized automatic machines.

 

But in a normal application, we often need to convert between two different interface types. At this point, we can use the popular USB interface, which can help us to switch to RS-232 interface and RS-485 interface.

 

In conclusion, RS-232 is suitable for short distance and low-speed transmission, while RS-485 is suitable for long distance transmission. RS-485 is a new interface standard aiming at the shortcomings of RS-232 interface. Because of its good anti-noise interference ability and multi-station ability, it has become the preferred standard.

4g router features of E-lins Technology

Category : 产品文章

With the development of new communication technologies and the continuous improvement of network efficiency and function of wireless communication, 4G has been widely used. 4G industrial-grade wireless routers are playing an increasingly important role in the applications of various industries, and the price is getting cheaper and cheaper. Currently, there are a lot of optional devices in the market, so how to choose one that can guarantee long-term use, stability and reliability, and affordable price is the problem that customers think about the most. The following is a specific selection reference for the 4G industrial wireless router of E-lins technology.

 

I. Industrial-grade design

1. Adopt high-performance industrial-grade 32-bit processor and adopt qualcomm chip, the world’s top wireless solution, with high processing speed, low power consumption, low heat output, strong compatibility and more stable, which can meet the requirement of 365 days a year, 7*24 hours long and stable operation without dropping the line.

2. Adopt high-performance industrial-grade communication module and high-quality communication module of huawei and other first-tier brands, with strong reception ability, stable signal and faster transmission.

The operating system uses OpenWRT, a highly modular, highly automated embedded Linux system, which makes the device more stable, has a large capacity of Flash and memory, and can support the requirements of customized development. High quality PCB circuit boards are manufactured with high quality materials and high standard. Stable industrial components are used for product components. All the machines are automated to realize patch production, ensuring the stability and reliability of the products. The power supply adopts wide voltage design to support dc5v-40v, with built-in anti-phase protection and over-voltage and over-current protection of the power supply, which can withstand the impact of instantaneous high voltage and current. Ethernet USES gigabit network port, built-in electromagnetic protection Ethernet interface built-in 1.5kv electromagnetic isolation protection, gigabit network port, faster transmission speed. The shell with strong anti-interference ability adopts thickened metal shell, shielding electromagnetic interference, and the equipment protection grade IP34, which is suitable for use in harsh industrial environment.

 

II. Powerful function

 

Multi-mode multi-card, load balancing

Expand network equipment and server bandwidth, increase throughput, enhance network data processing capacity, and improve network flexibility and availability.

 

Support global network formats

Support 2G, 3G and 4G networks of the three major domestic operators, or support Europe, southeast Asia, Africa, Latin America and other countries.

 

Support wired wireless backup

WAN port and LAN port can be flexibly switched to support wired and wireless backup of WAN port, with wired priority and wireless backup.

 

Serial transmission

Support simultaneous RS 232/485 serial port transmission.

 

Support APN/VPDN special network card, support a variety of VPN support APN/VPDN special network card use, at the same time support PPTP, L2TP, Ipsec, OpenVPN, GRE and other VPN.

 

Powerful WIFI function

WIFI supports 802.11b/g/n, WIFI AP, AP Client, repeater, relay bridge, WDS and other working modes, 802.11ac, or 5.8g (optional).

 

Support IP penetration function can achieve the IP address of the host IP obtained for the router, which is equivalent to the host directly plugging in the card to dial up the Internet to obtain the IP of the base station.

 

VLAN virtual LAN division through the division of VLAN, enhance the security of the LAN, VLAN technology, can be different locations, different networks, different users together, forming a virtual network environment. Support QOS, bandwidth speed limit support different network port bandwidth speed limit, IP speed limit, total bandwidth speed limit. Support DHCP, DDNS, firewalls, NAT and the function such as DMZ host support ICMP, TCP, UDP, Telnet, FTP, HTTP, HTTPS and network protocol support time to restart, SMS control, GPS/beidou positioning function (optional), support M2M cloud platform management, mobile monitoring and WEB monitoring, device data monitoring, traffic limit function, push resources, statistics, the remote device management (remote restart, WiFi switch), remote parameter modification, traffic restrictions, GPS tracking trajectory.

 

III. stable and reliable

1. Support hardware WDT watchdog, provide anti-dropping mechanism, and ensure that the data terminal is always online.

2. Support ICMP detection and traffic detection, automatically restart the equipment if network abnormality is found in time to ensure the stability and reliability of the system in long-term use.

3. Industrial-grade design, metal shell, anti-interference, anti-radiation, 95% humidity, no condensation, high temperature and low temperature resistance, minus 30 degrees to 75 degrees high temperature can work normally.

4. Our products have passed CCC certification, European CE certification and other certifications

 

Simple operation, easy to use

1. Simple Internet access, push-stick user card interface, insert mobile phone card/Internet of things card/special network card, and you can use the network port and WIFI after power on.

2. Support software and hardware to restore factory Settings, software can clear parameters, hardware RST one-key to restore factory Settings.

3. Product quick operation manual, WEB menu-type page, can quickly set up the device for use.

4. Diagnostic tools: log download and view, remote log record, ping detection, route tracking, easy to detect device information.

Classification of 4G industrial routers

Category : 技术相关

There are many types of 4G industrial routers, which can be divided into different categories from different perspectives. Different types of 4G industrial routers can be used in different environments. The following sections classify the 4G industrial routers from different perspectives.

According to the performance

From the perspective of performance, 4G industrial routers can be divided into linear router and non-linear router.

The so-called wire speed router can transmit freely according to the transmission medium bandwidth, basically without discontinuity and delay. The specific calculation method is the same as that of the switch line speed backplane bandwidth. A wire-speed router is a high-end router with very high port bandwidth and data forwarding capability that forwards packets at the media rate.

Non-wire-speed routers are mid – to low-end routers, but some new wire-access routers also have wire-speed capabilities. The performance of router is mainly affected by CPU performance. If the CPU performance is high, the 4G industrial router is more likely to be a high-performing wire-speed router.

Speed is generally not a measure of a router, and data throughput is one of the references used to measure a router’s maximum data throughput. The routers with the capacity of the rear plates of 4G industrial routers greater than 40Gbps are called high-grade routers. The routers with the capacity of the rear plates between 25Gbps and 40Gbps are called midrange routers, while those with the capacity lower than 25Gbps are considered as low-grade routers. This kind of dividing way is not so absolute, specific parameter needs to make distinguishing according to each manufacturer specific parameter.

According to the structure of the points

The 4G industrial router can be divided into modular router and non-modular router according to the structure Angle.

Modular routing generally only provides basic routing function when leaving the factory. Its interface type and partial extension function are configured according to the actual needs of users. Users can choose corresponding modules according to the network type they need to connect. Different modules can also provide different connectivity and management capabilities. For example, the vast majority of modular routers allow users to choose network interfaces, VPNS, firewalls and other functions, most of which are modular routers.

Routers H685/H700/H720/H750/H820/H820Q/H820QO  from E-Lins are all modular router, can meet the requirements from all over the world.

Non-modular routers are mostly low-end routers, which are mostly used in civilian environments. Primarily used to connect small business customers within homes or isps, supporting virtual private network protocols such as SLIP, PPP, PPTP, and IPSec. These protocols to run on each port, such as ADSL will increase home broadband availability, which will increase the burden of accessing routers. In the future, such router ports will run multiple protocols while avoiding the telephone switched network.

According to the function points

The 4G industrial router is divided into general router and special router. The common civilian router is the general router, that is, the router that can normally use the routing function under the general environment, and there is no other special requirement scenario.

The special router optimizes the routing interface, hardware and so on to realize a certain function. For example, the foreign trade special router changes the local IP through the special router, which can also quickly access some foreign trade stations in China, which is more convenient.

According to the interface points

4G industrial routers can support SDH stm-1 interface, SDH stm-4 interface and SDH stm-16 interface. At present, the router supporting SDH stm-64 interface is high-end 4G industrial router. However, other interfaces are relatively weak, among which stm-1 has two types of optical interface and electrical interface. Stm-1 electrical interface is suitable for local situations where the interference signal is weak. The light interface is usually used for stm-4, stm-16 and stm-64.

according to the perspective of the object of use

The 4G industrial routers can be divided into core router (core level), distribution router (enterprise level) and access router (home level) according to the perspective of the object of use.

The core router, which is the router that forwards packets to the host computer in the network (but not between networks), is the key device to realize Interner network interconnection with other levels of routers. Often used by telecom operators or isps. The throughput of core router is larger, and the requirement of speed and reliability is higher. In order to obtain high reliability, the network system generally adopts traditional redundant technology such as hot backup, dual power supply and dual data path, so that the reliability of backbone router is not a problem.

Distributed routers are used to connect multiple logically separate networks because there are many connected objects, the system is relatively simple, and the data traffic is relatively small. In addition to connecting different networks, distribution routers also need to choose smooth and rapid short-cuts to improve the communication speed, reduce the network communication load, save system resources while improving the unimpeded rate, and maximize the benefit of the network system.

The access router is mainly used for network interconnection in the small local area network. It is often used in the case of small area and simple network environment such as home, small enterprise or net bar.

Industrial Wireless:Beware of COTS

Category : 技术相关

Industrial Wireless:Beware of COTS, This is a tip of  Broken Signal Solutions.

Just because 802.11 is a commercial off-the-shelf (COTS) standard doesn’t mean that COTS products can be used in the industrial environment, warns Advantech’s Lochhaas. Industrially hardened access points “will survive in the industrial environment when exposed to extremes of temperature, dust, humidity, hazardous vapors and other common situations,” he says. “So when selecting your industrial wireless products, be certain to determine their suitability for the service you wish to use them in.”

E-lins notes, “Industrial environments are harder on wireless than any office would ever be,” which can drastically shorten the useful lifespan of wireless equipment. You get what you pay for in this world, and using office-grade networking equipment to save small amounts of money upfront will turn out to be a huge mistake when you have to pay for it later with downtime and repairs.”

E-lins’s comments could serve as a handy maxim to guide your approach not just to COTS components, but to wireless implementation in general.

Industrial LTE Router For Secure M2M Communication

Category : 其他, 技术相关

E-Lins  has expanded it’s M2M router  in  LTE. This router solutions for LAN-WAN , GPRS , UMTS and LTE now available .

E-Lins Industrial LTE router is a high- performance router for industrial use , which can be sensitive data securely via cellular networks. The integrated firewall and VPN support protect your application secure from unauthorized access. If LTE is not available, the system automatically switches to UMTS / GPRS / EDGE.In addition, the data connection and the mobile network quality to be monitored. If necessary, a message is sent or rebuilt the cellular connection.The configuration of the router via the built-in web server, or XML files in the remote mode.

Other important features are:

Supply voltage : DC5V~40V is the default, DC5V~50V is the option
extended temperature range of -30 ~ 75°C
integrated overvoltage protection

Optional all Router with RS232 and RS485 interface for transparent serial transmission over a TCP / IP are available .