1. Long-distance wireless transmission (up to 500 m in open area, 10 kbps air data rate). 2. Operating frequency range: 433–458.5 MHz, up to 255 communication channels. Maximum transmit power: 100 mW (20 dBm), with 10 adjustable power levels. 3. Built-in MCU; communicates with external devices via serial interface. Supports sending up to 31 bytes per transmission. 4. Supports one-to-one and one-to-many transparent transmission via ID configuration. Changing the serial port baud rate synchronously adjusts the over-the-air data rate (10 kbps–100 kbps). 5. AT command mode is available within the first three minutes after power-on. Send “AT+ENABLE=1” to enter AT mode for parameter configuration. After three minutes, AT commands are no longer recognized and 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-field transmission distance: 500 m Dimensions (without antenna): 74 × 24 × 16 mm Usage instructions (for 2 or more units): - With 2 units: Module 1 and Module 2 exchange data bidirectionally. - With 3 or more units: One unit operates as master; others operate as slaves. Communication follows RS485 bus topology: the master transmits and all slaves receive; any slave may transmit, and the master plus other slaves 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 display settings. Dimensional tolerance: ±1–3 cm.