1. Long-distance wireless transmission (up to 500 meters in open area, 10 kbps air data rate). 2. Operating frequency range: 433–458.5 MHz, with up to 255 communication channels. Maximum transmit power: 100 mW (20 dBm), adjustable across 10 power levels. 3. Built-in microcontroller unit (MCU); communicates with external devices via serial interface. Supports up to 31 bytes per transmission. 4. Supports one-to-one and one-to-many transparent transmission via configurable device ID. Serial port baud rate adjustment synchronously changes the over-the-air data rate (10 kbps to 100 kbps). 5. AT command mode is available only within the first three minutes after power-on. Send “AT+ENABLE=1” to enter AT mode for parameter configuration. After three minutes, the module operates exclusively in transparent transmission mode; AT commands are treated as payload data. Product Name: VHF/UHF Radio Modem RS485 Wireless Transceiver, 20 dBm, 433 MHz Working voltage: 4.5 V–5.5 V Interface: RS485 (5 V, GND, A+, B−) Frequency: 433 MHz Transmit power: −40 dBm to +20 dBm Receiver sensitivity: −114 dBm Operating temperature: −25 °C to +75 °C Transparent transmission baud rates: 1200, 2400, 4800, 9600 (default), 19200 bps Open-area transmission distance: 500 m Dimensions (without antenna): 74 × 24 × 16 mm Usage instructions: - For two modules: Module 1 and Module 2 communicate bidirectionally. - For three or more modules: Configure one as master and the others as slaves. Communication emulates a wired RS485 bus topology. The master transmits data received by all slaves; any slave may transmit, and the master plus other slaves will receive. Only one device (master or slave) may transmit at a time. Applications: - IP PTZ cameras - Modbus temperature sensors - LED controllers - RS485 relays - Remote control and remote monitoring systems - Wireless meters - Home automation systems - Access control systems - Smart meters Color: Blue Material: Plastic + metal Package contents: - 2 × 433–458 MHz VHF/UHF Radio Modem RS485 Transceivers (with enclosure) Note: Color appearance may vary slightly due to lighting and screen settings. Dimensional tolerance: ±1–3 cm.