The rapid development of communication networks has brought great convenience to all walks of life, and the photovoltaic industry is no exception. When building a photovoltaic power station, you can check the operation information of the power station at any time with your mobile phone, such as DC voltage, current, output power, daily power generation, etc. If there is a power station failure, the mobile phone APP monitoring program will be notified as soon as possible , And the type of failure can be found. Many problems can be solved remotely, shortening the repair time of the power station and reducing the power loss of the power station. So, how does the inverter's operating data appear on the mobile phone APP monitoring
In fact, the inverter's operating data cannot be directly uploaded to the mobile phone APP monitoring software, which requires more than 4 conversion processes. The operating data of the inverter is generally stored on the DSP control chip, such as Texas Instruments’ TMS320F28075. To transmit to the outside, a dedicated communication chip is also required. Now 90% of the inverter uses an ARM structure chip. Very strong strength. Then through the communication hardware interface, upload to the inverter manufacturer's cloud platform server with a certain communication protocol, and then turn it into data after decoding. Our mobile terminal or computer terminal accesses the cloud platform server through the website, and you can see the reverse The operating data of the transformer.
Communication hardware interface
The current photovoltaic inverter has three interfaces: RS485, RS232, and USB. These interfaces have their own characteristics and uses.
RS232 and RS485 are the most classic interfaces. The difference between the two is: RS-232 is suitable for communication between local devices. The transmission distance is generally no more than 20 meters. Only one-to-one communication is allowed, that is, one data collector is equipped with one reverse Inverter, suitable for household power stations or small industrial and commercial power stations; RS-485 transmission distance is tens of meters to thousands of meters, the interface allows one-to-many, that is, one data collector with multiple inverters, suitable for medium and large Power station.
USB (Universal Serial Bus) is currently a widely used interface specification on computers. The interface is fast, easy to connect, and does not require an external power supply. Due to the good compatibility of USB, the application is becoming more and more widely used in recent years. In the inverter developed, the USB interface gradually replaces the RS232 interface. The USB interface can be connected to the collector one-to-one or directly connected to the computer. The USB can also connect up to 127 devices in series.
Monitoring data transmission method
Data is transmitted from the inverter to the server. There are currently three commonly used schemes for data transmission, GPRS/3G/4G/5G, WIFI, and LAN. GPRS/3G/4G/5G data collector, built-in mobile phone SIM data card, the inverter data is first sent to the server of the mobile phone operator, and then uploaded to the server of the inverter company. The advantage of GPRS/3G/4G/5G is that it does not require a broadband network and is suitable for places where it is inconvenient to set up a network. The disadvantage is that it requires data traffic. The difference between WIFI and LAN is that WIFI transmits data wirelessly, and LAN is wired transmission. Its advantage is that it does not require traffic costs. The disadvantage is that the distance of wireless WIFI is limited. Wired LAN requires a network cable and a broadband network.
Communication protocols, from inverters to data collectors, and some equipment and instruments, have to upload data to the cloud server. Each company’s technology is different. In order to unify and facilitate the transmission of data between different devices, it is generally used on-site Field bus technology, there are many types of field buses, such as Profibus, Interbus, DeviceNet, ControINet, Modbus, CC-link, HART and so on. The photovoltaic industry adopts Modbus more. ModBus features:
(1) Standard and open, users can use Modbus protocol for free and with confidence, without paying license fees, and will not infringe on intellectual property rights. Currently, there are more than 400 manufacturers supporting Modbus and more than 600 products supporting Modbus.
(2) Modbus can support a variety of electrical interfaces, such as RS-232, RS-485, USB, etc., and can also be transmitted on various media, such as twisted pair, optical fiber, wireless, etc. The inverter generally uses the RS485 interface for Modbus communication.
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4GB Memory + 16GB-128GB Storage
USB 2.0*6 + USB 3.0*1, Output current:2A/road
4 *RS232 + 1* RS485
Storage Temperature:-40 - +80℃
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Data from inverters to mobile phones requires various technologies such as hardware and software. RS485, 232 and USB are a physical interface, or simply hardware. MODBUS is an international standard communication protocol, which is simply software. GPRS, WIFI, LAN are a kind of physical transmission channel.