DFRobot RS485-to-UART Module with Active Isolation

This RS485-to-UART module by DFRobot is used for secure signal conversion between industrial RS485 systems and microcontrollers such as Arduino boards. The module features complete galvanic isolation of both the signal line and power supply. The integrated power isolation provides up to 12 V and 2 W for connected low-power devices, enabling the supply of small RS485 devices. The UART connection supports 3.3 V and 5 V logic levels, making the module compatible with most microcontroller platforms. An industrial-grade RS485 connector facilitates connection to sensors and control devices. The PCB is manufactured using immersion gold technique and features a switchable 120-ohm termination resistor for different bus configurations. The advanced protection circuitry includes ESD protection up to 15 kV, short circuit, and bus fault protection. The module is suitable for industrial applications, control systems, and all environments where reliable and isolated RS485 communication is required.

Recommended Accessories:

• Ultrasonic 9-in-1 RS485 Weather Station Sensor for Arduino
• Ultrasonic 7-in-1 RS485 Weather Station Sensor for Arduino

Features:

• The module uses combined signal and power isolation for increased operational safety.
• An industrial-grade RS485 connector allows easy connection to RS485 devices.
• The integrated 12-V output (up to approx. 160 mA) allows the operation of small RS485 consumers.
• The UART input is compatible with 3.3-V and 5-V levels and supports various microcontrollers.
• The board is manufactured using immersion gold technique and offers high PCB quality.
• A switchable 120-ohm termination resistor allows flexible adaptation to the bus.
• External 12-V supply is supported if additional power reserves are needed.
• The protection circuits include TVS ESD protection, short circuit, and bus fault protection.

Application Examples:

• Modbus communication between RS485 devices and microcontrollers.
• Integration of industrial sensors in measurement and control systems.
• Establishing galvanically isolated communication channels.
• RS485 networks with many participants in industrial or laboratory environments.
• Data transmission in environments with electrical interference.

Documentation:

• Dfrobot Wiki

Technical Data:

• Manufacturer: DFRRobot
• Manufacturer SKU: DFR0845
• Supply Voltage: 3.3–5 V
• Communication: UART, RS485
• Baud Rate: up to 1 Mbit/s
• Output Power: up to 12 V 2 W (approx. 160 mA)
• Isolation Voltage: 3000 VDC
• ESD Protection: up to 15 kV
• Bus Load: 1/8 Unit Load, up to 256 participants
• Protection Functions: Bus Fault Protection, Bus Driver Short Circuit Protection
• Temperature Range: –40 to +105 °C
• Dimensions: 45 × 36 × 18 mm
• Weight: 35 g

Scope of Delivery:

• 1 × RS485-to-UART Module
• 1 × Gravity-4-Pin UART Cable