USB to RS485 RS422 DB9 Converter – FTDI FT232RL+SP485, 1200m, 3 LEDs | DTECH DT-5019

The USB to RS485 RS422 DB9 converter DT-5019 from DTECH connects any USB 2.0 port to RS-485 and RS-422 serial equipment through a DB9 female connector — the same 9-pin socket found on industrial PLCs, power meters, access controllers, SCADA RTUs and process automation field devices with built-in serial ports. Unlike USB-to-RS485 cables that terminate in bare wire leads or screw terminals, the DT-5019 uses a DB9 connector on the serial end, allowing direct plug-in connection to equipment without additional wiring. The cable is built around an FTDI FT232RL + SP485 dual chip architecture confirmed by DTECH, delivers auto direction switching with no handshake signals required, and supports communication distances of up to 1200m on the RS-485/422 side.

USB to RS485 RS422 DB9 Converter – FTDI FT232RL+SP485 Dual Chip Architecture

The DT-5019 uses two discrete chips for a clean division of roles. The FTDI FT232RL handles USB-to-UART conversion on the PC side — it is among the most widely supported USB serial bridge controllers in the industry, with signed drivers maintained by FTDI at ftdichip.com/products/ft232rl/. The SP485 is a dedicated RS-485/RS-422 transceiver that drives the differential serial bus signals on the field side. Separating these functions into two purpose-built chips, rather than relying on a single multi-function IC, results in more stable long-distance transmission and better electrical isolation between the USB and RS-485/422 domains. An automatic I/O circuit controls the RS-485 data direction without requiring any handshake signals — no RTS, no DTR, no jumper settings — and auto baud rate detection matches the connected device’s speed from 300bps to 460800bps automatically. The interface is compliant with EIA/TIA RS-485 and RS-422 standards.

DB9 Female Connector and 1200m Distance – Point-to-Multipoint Bus for Up to 32 Devices

The DB9 female connector on the RS-485/422 end carries T/R+, T/R−, RXD+, RXD− and GND — the standard differential signal pairs for RS-485 (half-duplex, 3-wire: T/R+, T/R−, GND) and RS-422 (full-duplex, 5-wire: T/R+, T/R−, RXD+, RXD−, GND). This DB9 form factor connects directly to industrial equipment without terminal block adapters, saving installation time in panel and rack-mount environments. On the RS-485/422 bus, the DT-5019 supports point-to-multipoint connections for up to 32 devices on a single cable run, covering Modbus RTU networks, RS-422 multi-sensor arrays, building management field buses and industrial control networks. The maximum supported communication distance is 1200m on the RS-485/422 side — allowing a single cable to span a large factory floor, warehouse or multi-storey building from a centrally located PC or industrial computer. The USB host side operates within a maximum 5m run.

Three-Colour LED Indicators and Broad OS Support

The three built-in LED indicators give instant working status feedback without requiring serial monitor software: the red Power LED confirms the adapter is enumerated and active; the green TXD LED flashes during data transmission to the bus; and the yellow RXD LED flashes during data reception from the bus. In multi-device bus installations, these LEDs are practical for quickly identifying whether a communication problem is on the transmit side, the receive side, or a power or enumeration issue. The DT-5019 installs as a virtual COM port on Windows XP, Vista, 7, 8, 8.1, 10, Windows Server 2008, macOS and Linux, and draws power entirely from the USB bus — no external power supply required.

Typical applications include Modbus RTU over RS-485 for industrial automation control systems, PLC programming and monitoring, building access control panels, energy meter data acquisition, parking management systems, attendance machine communication, and any scenario requiring a reliable USB to RS485 RS422 DB9 converter with a plug-in serial connector.

For tri-protocol coverage also including RS232 and terminal-block wiring, see the DTECH DT-5019C USB to RS485 RS422 RS232 adapter. Browse the full industrial serial product range at bam.ae for USB-to-RS232, RS485, RS422 and TTL serial adapters.

Specifications Table