GPRS DTU is also called gprs data transmission terminal. It is a gprs networking device formed by the gprs module embedded on the circuit board and a sheet metal shell. It is a wireless version of the serial port server. Its functions are similar to the serial port server. Utilize China Mobile and China Unicom’s GSM network across the country to transmit data through SMS. Can. Use high-performance industrial-grade 8/16/32-bit communication processor and industrial-grade wireless module, use embedded real-time operating system as software support platform, and provide RS232 and RS485 (or RS422) interfaces, which can directly connect to serial devices, to achieve transparent data transmission function.
Comment fonctionne le DTU GPRS
GPRS DTU initiates a TCP or UDP communication request to the data center through the data center’s IP address (if the center domain name is used, first resolve the center IP address through the center domain name) and port number and other parameters. After getting the response from the center, GPRS DTU considers that the handshake with the center is successful, and then keeps the communication connection existing. If the communication connection is interrupted, GPRS DTU will immediately re-handshake with the center.
La connexion de communication TCP/UDP ayant été établie, la communication bidirectionnelle des données peut être effectuée.
For DTU, as long as two-way communication with the data center is established, it is relatively simple to complete the conversion of user serial port data and GPRS network data packets. Once the user’s serial port data is received, DTU immediately encapsulates the serial port data in a TCP/UDP packet and sends it to the data center. On the contrary, when DTU receives the TCP/UDP packet from the data center, it takes out the data content and immediately sends it to the user device through the serial port. Through the wired data collection center, two-way communication is performed with many GPRS DTUs at the same time.
GPRS DTU application scenarios
1) Only wireless communication environment can be used on site. When the equipment at the data collection site needs to work on the move, or the collection site is in the wild, a wired communication environment cannot be provided. At this time, using a GPRS wireless network may be a good choice. Since the coverage rate of the GPRS network is currently very high, most areas across the country are covered by GPRS signals.
2) On-site terminal transmission intervals are dispersed. Since the GPRS network is a public network covering the whole country, a major advantage of using GPRS to transmit data is that on-site collection points can be spread across the country step by step, and the interval between the data center and on-site collection points is not affected by limit. This very obvious advantage of wireless public network communication (including GPRS/CDMA network, 3G network, etc.) cannot be achieved by dedicated wireless communication networks ( such as data transmission radio stations, WiMax, WLAN, etc.).
3) Appropriate data real-time performance requires the current GPRS network, whose transmission data delay is in the second-level range. Most of the time, the average overall delay of GPRS data communication is about 2 seconds. In other words, the data packet sent by the GPRS DTU end will arrive at the data center roughly after 2 seconds. On the contrary, the data packet from the slave data also arrives at the GPRS DTU roughly 2 seconds later. In general, the real-time nature of GPRS can meet the requirements of most industry applications. However, for some specific application systems, if they cannot bear an average delay of about 2 seconds, then the GPRS communication method may not be suitable. (In addition, the transmission delay of CDMA network is also about 1 second to 2 seconds). From another perspective, if the system we want to design needs to transmit data through the GPRS network, then we must consider this delay when designing the communication protocol.
4) Appropriate data communication rate The data communication rate between GPRS DTU and the data center is generally between 10kbps-60kbps. So in other words, GPRS DTU can continuously send data to the center at a speed of 10bps-60kbps, and vice versa. (Supplementary note: The average data communication rate of domestic CDMA networks can reach about 40kbps-90kbps) From the perspective of system application reliability, when the average data communication volume of our application system itself is within 30kbps, we use the GPRS network to carry out data Transmission is more suitable. From another perspective, if the system we want to design is to transmit data through the GPRS network, then the average data communication volume needs to be controlled within 30kbps.
Nowadays, 4G network is also quite mature and covers a wide area. If you need high-speed network, you can choose 4G DTU. 4G DTU has the industry’s ultra-low power consumption performance. It adopts multi-level sleep and wake-up modes, and its working power consumption, standby power consumption, and sleep power consumption (Sleep power consumption <5mA) is much lower than similar products in the industry, and has obvious advantages in application scenarios where power is inconvenient. Supports dedicated line APN transmission or virtual private network VPDN transmission, and supports the ModBus communication protocol to fully ensure the security and accuracy of the data communication transmission process and avoid possible leakage of information during the entire transmission process. If you consider that the cost of 4G DTU is high, you can consider using Cat-1 data transmission terminals. At present, Zongheng Intelligent Control's Cat-1 series DTU has won recognition from customers for its cost-effectiveness and stable transmission quality.