1、The voltage conversion sensor module is DD4012SA, a high-efficiency and low-heat voltage converter 2、By modifying the RS485 address, up to 247 module s can be connected (More than 16 devices, it is recommended to use RS485 repeater) 3、Temperature and humidity sensor is AM2320 4、RTU protocol, 03 Read, 06 Write 5、Widely used for dehumidifiers, testing and inspection equipment, automotive, automation, gas stations, home appliances, humidity control, medical, and other relevant humidity measurement and control Description: Temperature and humidity combined sensor AM2320 digital temperature and humidity sensor is a digital signal output has been calibrated. Using special temperature and humidity acquisition technology, ensure that the product has a very high reliability and excellent long-term stability. Sensor consists of a capacitive moisture element and an integrated high-precision temperature measurement devices, and connected with a high-performance microprocessor. The product has excellent quality, super fast response, strong anti-interference ability. Features: By modifying the RS485 address, up to 247 module s can be connected (More than 16 devices, it is recommended to use RS485 repeater). Temperature and humidity sensor is AM2320. RTU protocol, 03 Read, 06 Write. Widely used for dehumidifiers, testing and inspection equipment, automotive, automation, gas stations, home appliances, humidity control, medical, and other relevant humidity measurement and control. Specifications: Working Current: Digital tube turn off is 5MA(12V), Digital tube turn on is 18MA(12V) Serial Baud Rate: 9600(default), N, 8, 1 How to use: 1, Display "Eror" after power-on. If "Eror" is displayed for a long time, it indicates that the sensor is not connected or is damaged. 2, After 5 seconds, display the temperature or humidity. 3, Trigger "KEY" button to switch the display temperature and humidity.(This parameter is powered down memory). 4, Press and hold the "KEY" button for 3 seconds to turn off or turn on the display.(This parameter is also powered down memory). Note: If the digital tube is turn off after power-on, press and hold the "KEY" button until the digital tube is turn on. Wiring Diagram: Note: With the built-in sensor version (R444A01_A), turn on the display for a long time will let the temperature rise 1-2 degrees Celsius. It is recommended to turn off the digital tube, or use a version with an external sensor (R444A01_B) Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. Package Includes: 1 x Module 1 x External Sensor