USB to RS485 Converter Module

This DFRobot USB stick connects a computer to RS485 devices via USB. The RS485 line goes to a removable screw terminal with A+, B-, GND and 5V. The converter works in half duplex, several RS485 devices can share the bus, and according to DFRobot the RS485 side has lightning protection.

According to the current DFRobot page, the converter uses a CH340; earlier information named a PL2303. Device Manager shows which chip is fitted after plugging in; the matching driver is available from the chip maker.

Features:

• USB to RS485, half duplex with automatic direction control
• Removable screw terminal with A+, B-, GND and 5V
• Several RS485 devices in parallel on the bus
• Lightning protection on the RS485 side according to DFRobot
• LEDs for transmit (TX) and receive (RX)
• Self-resetting fuse and protection diodes
• Runs on Windows, Linux, macOS and Android

Application Examples:

• Reading Modbus RTU sensors such as weather stations or soil sensors on a computer
• Configuring energy meters, controllers and other RS485 devices
• Commissioning and troubleshooting RS485 buses

Documentation:

• DFRobot FIT0737 product page
• CH340 driver for Windows from chip maker WCH

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: FIT0737
• USB chip: CH340 according to DFRobot, earlier information PL2303
• Standard: compatible with USB 1.1, 2.0 and 3.0, RS485
• Baud rate: 2400 bit/s to 115.2 kbit/s
• Operating mode: asynchronous, half duplex (RS485)
• Load: up to 32 RS485 devices
• Transmission distance: up to 2 km at 57.6 kbit/s
• Power consumption: 1 W
• Connection: 4-pin screw terminal, A+, B-, GND, 5V (printing)
• Operating temperature: -40 °C to 85 °C
• Dimensions: about 83 × 26 × 17 mm (DFRobot)
• Weight: 20.6 g

Scope of Delivery:

• 1× USB to RS485 Converter Module