Rika Sensor is a sensor manufacturer and environmental monitoring solution provider with 10+ years of industry experience.

Popular science: four data transmission methods for temperature and humidity sensors

by:Rika Sensors     2021-09-04
Popular science: four data transmission methods for temperature and humidity sensors
Over the past few decades, the sensor industry has undergone earth-shaking changes. Advances in technology and the Internet of Things have led to more diverse ways of transmitting data. Various types of sensors can not only monitor data in real time, but also Choose different data transmission methods to upload to the cloud platform for use scenarios, so that we can access it whenever we need it. Take the temperature and humidity sensor as an example, let's talk about the four data transmission methods of the sensor.

First of all, let me state that these four data transmission methods are not limited to temperature and humidity sensors. Because the temperature and humidity sensor is a common sensor in our daily life, the data uploading method is more comprehensive and relatively representative.

There are four types of data uploading for temperature and humidity sensors: 485 type, analog type, network type, and wireless type.

1, 485 type

485 type data transmission, the full name is RS-485. RS-485 is developed on the basis of RS-422, so some electrical regulations are similar to RS-422, for example, all adopt balanced transmission mode, and all need to connect terminal resistors on the transmission line. And 485 can choose two-wire or four-wire mode, and the two-wire system can realize true multi-point two-way communication. When the four-wire system is adopted, only point-to-many communication can be realized. However, 32 devices can be connected to either the two-wire system or the four-wire system bus.

When the applicable range of RS-485 is from tens of meters to thousands of meters, the RS-485 serial bus standard is adopted. It is connected to the environmental monitoring host through the RS-485 interface, and uploaded from the environmental monitoring host to the cloud platform; or directly connected to the computer through USB to 485 to achieve real-time data display, historical data query, data export and other functions.

2. Analog quantity type

In the previous article, the analog quantity type was introduced in detail. Because of the length of the article, I will focus on the analog quantity data transmission method. In the control system, whether it is input or output, a parameter is either an analog quantity or a switch quantity. The analog temperature and humidity sensor uses analog data transmission. The analog sensor sends out a continuous signal, using voltage, current, and resistance to indicate the size of the measured parameter.

Take the analog temperature and humidity sensor as an example. There are several types of output signals: 0-20mA, 0-5V, and 0-10V.

Take 0-20mA output signal conversion calculation as an example: for example, the range is -40~+80℃, 4~20mA output, when the output signal is 12mA, calculate the current temperature value. The span of this temperature range is 120°C, when expressed by a 16mA current signal, 120°C/16mAu003d7.5°C/mA, that is, 1mA represents a temperature change of 7.5°C, and the measured value is 12mA-4mAu003d8mA, 8mA*7.5°C/mAu003d 60°C. 60+(-40)u003d20℃, the current temperature is 20℃. The other two can be deduced by analogy.

3. Network type

①Ethernet

Ethernet is currently the most commonly used LAN technology, replacing other LAN technologies such as token ring, FDDI and ARCNET. The Ethernet type transmission method can upload the collected data to the server through the Ethernet method. Make full use of the established Ethernet communication network to realize data collection and transmission, and achieve the purpose of centralized monitoring. Can greatly reduce the amount of construction, improve construction efficiency and maintenance costs.

②WIFI type

The WIFI type wireless data transmission method can upload the collected data to the server through WIFI method. Make full use of the established WIFI communication network to realize data collection and transmission, and achieve the purpose of centralized monitoring. Can greatly reduce the amount of construction, improve construction efficiency and maintenance costs.

③GPRS type

GPRS is the abbreviation of general packet radio service technology. It is a mobile data service available to GSM mobile phone users and belongs to the data transmission technology in the second generation of mobile communications. The temperature and humidity transmitter based on GPRS transmission only needs a SIM card of China Mobile, China Unicom or Telecom to upload the collected temperature and humidity data to the server through the network base station.

4. Radio type

Radio refers to electromagnetic waves that propagate in free space (including air and vacuum), and radio technology is a technology that transmits signals through radio waves.

The radio type sensor adopts wireless spread spectrum technology, the communication distance is long, the line of sight can reach 800 meters, the penetrating ability is strong, and it can penetrate 3~4 concrete walls. Due to the frequency modulation technology, the communication is Ordinary radio equipment has strong anti-interference ability.


sensor solution has become a crucial product for marketers, especially when it comes to brand building and engaging potential customers.
The best for environmental monitoring systems is one that works best for your needs and what you can support in your home. Among Hunan Rika Electronic Tech Co.,Ltd 's diversified list of products at different price ranges, you will surely find your one with high quality. make your choice at Rika Sensors!
sensor solution has a very good repute over the global market.
Custom message
这里可以自定义设置
Chat Online
Chat Online
Chat Online inputting...