Function: 1. HRI-485_ 1: ESP32-C3 main control chip, default function: LoRa RS485 2. HRI-485_ 2: ESP32 main control chip, default function: LoRa; Ethernet (note: this product does not support RS485) 3. HRI-485_ 3: ESP32 main control chip, default function: (Ethernet RS485) Main control chip: ESP32-C3FN4/ESP32DOWDQ6 LoRa chip: For SX1262 Maximum transmission power: 21 ± 1dBm Maximum receiving sensitivity: -139dBm Power supply voltage: DC 4.5-28V Working temperature: -40~85 ℃ Rail width: 35mm LORA protocol: Private protocol, supporting data encryption Frequency: 470-490MHz (470M+200K * N) 863-883MHz (863M+200K * N) 902-922MHz (902M+200K * N) N: 0-100 Working humidity: 10%~90%, non condensing Antenna impedance: 50 Ω Address code: 0000~FFFF Baud: 1200/2400/4800/9600/19200/38400/57600/115200 Storage: 1024 bytes Instructions for use: Describe some application modes of HRI-485X without considering protocols: 1. Overall: 4851 can achieve multiple networking modes, but can only work within the local area network. To access the network, 4852 is required; Generally speaking, 4852 only serves as the gateway for 4851 to access the network; After 4853 is connected to a machine, it can be used separately (without LoRa function). 2. How to access the network: Both 4852 and 4853 have two access modes, 4G or Ethernet (router). There is often a misconception here, which is the "4851Gateway mode". It can only be used as a gateway for the local area network, managing devices in the "4851Node" mode below, and cannot directly access the internet. This is different from Heltec's previous gateway products, please note. 3. The LTE function can only be used in the 470MHz band of Chinese Mainland at present, and other regions do not support t