CONN-USB-RS485
Convertisseur USB ↔ RS485 FTDI
Adaptateur USB ↔ RS485 FTDI FT232 — dialogue PC ↔ automate.
Technical analysis
This converter gives any PC or Raspberry Pi an RS-485 port over USB, built around an FTDI FT232RL bridge renowned for its stable drivers (Windows/Linux/macOS). It is the field tool for diagnosing a Modbus RTU bus, querying a PLC, or turning a Raspberry Pi into a collection gateway.
Nuance: the FT232RL is only the USB-serial bridge; the differential behaviour (drive, protection) comes from the RS-485 transceiver on the board, which varies by model. Beware too of counterfeit FTDI chips, a source of temperamental drivers. To integrate RS-485 into an embedded node rather than over USB, you use a MAX485 directly.
Verified specifications
Every figure below is sourced from the manufacturer datasheet.
- USB-UART bridge
- FTDI FT232RL (USB 2.0 Full Speed)
- Data rate
- 300 baud to 3 Mbaud
- Buffers
- receive 128 B / transmit 256 B
- UART frame
- 7/8 data bits, 1/2 stop, configurable parity
- Field side
- RS-485 transceiver (differential)
References & standards
📄 Official manufacturer datasheet — FTDI (pont FT232) + transceiver RS-485
Applicable standards
- TIA/EIA-485 — Physical layer on the field side (the FT232 provides USB-UART, an external transceiver does the differential).
- Modbus RTU — Typical use: communicating in Modbus RTU with industrial equipment from a PC.