1. Introdución
The UOTEK UT-850N is a universal USB to RS-485/422 serial converter designed to bridge the communication gap between modern PCs and industrial equipment utilizing RS-485/422 interfaces. This device converts USB signals to balanced differential RS-485/422 signals, providing essential connectivity without requiring an external power supply. It features surge and ESD protection, ensuring reliable data transmission in various environments.
This manual provides detailed instructions for the setup, operation, and maintenance of your UT-850N converter.

Image 1.1: UOTEK UT-850N USB to RS-485/422 Serial Converter with included terminal block.
2. Características
- Estándares: USBV1.1, RS-485/422 EIA.
- Sinal USB: VCC, DATA+, DATA-, GND, FG.
- RS-485 Signal: T+, T-, GND.
- RS-422 Signal: T+, T-, R+, R-, GND.
- Modo de traballo: Asynchronous, point-to-point or point-to-multipoint, 2-wire half-duplex or 4-wire full-duplex.
- Control de dirección: Automatic data flow direction control technology.
- Taxa de transmisión: 300-921.6Kbps, auto-detect serial signal.
- Capacidade de carga: Supports point-to-multipoint communication, connecting up to 32 sets of RS-422 or RS-485 devices.
- Distancia de transmisión: Up to 5,000m (9,600bps) for RS-485/422; up to 5m for USB.
- Protección portuaria: Surge protection, ±15KV ESD protection.
- Conectores: USB-A male, DB9 male.
- Medios de transmisión: Twisted-pair or shielded cable.
- Lonxitude do cable: 1.5 m.
- Temperatura de funcionamento: -20 °C a 75 °C.
- Humidade relativa: 5% a 95%.
- Soporte do sistema operativo: Windows (Android/2000/2003/2008/2012/XP/Vista/7/8/8.1/10/CE), Mac, Linux.
3. Configuración
3.1 Instalación do controlador
For Windows 8, Windows 10, and newer operating systems, the UT-850N converter typically operates driver-free (plug & play). For older operating systems such as Windows 2000/2003/XP/Vista/7, or for specific Linux/Mac OS versions, driver installation may be required. Please refer to the manufacturer's website for the latest driver downloads if automatic installation does not occur.

Image 3.1: The UT-850N converter supports various operating systems, including Windows, Mac, Linux, and Android.
3.2 Conexión de hardware
- Connect the USB-A male connector of the UT-850N to an available USB port on your computer.
- Identify the RS-485/422 interface on your industrial device.
- Connect the DB9 male connector of the UT-850N to your RS-485/422 device. Use the included terminal block for screw-terminal connections if your device requires it.

Image 3.2: The UT-850N converter connected to a terminal block for RS-485/422 wiring.
3.3 Wiring Diagrams and Pin Assignments
The UT-850N uses a DB9 male connector for RS-485/422. The pin assignments are crucial for correct communication. Refer to the following diagrams for standard wiring configurations.

Image 3.3: Pin assignments for DB9 male connector and physical dimensions of the UT-850N.

Image 3.4: Wiring diagrams for USB to RS-485 (point-to-point, multipoint, half-duplex) and USB to RS-422 (point-to-point, multipoint, full-duplex) connections.
4. En funcionamento
4.1 Modos de traballo
The UT-850N supports both RS-485 (2-wire half-duplex) and RS-422 (4-wire full-duplex) communication modes. It can be configured for point-to-point or point-to-multipoint communication. The device features internal zero-delay auto receiving and transmitting functions, automatically controlling data flow direction without requiring handshake signals (RTS, DTR).
4.2 Taxa de baudios
The converter automatically detects the serial signal baud rate, supporting a range from 300bps to 921.6Kbps.
4.3 Indicadores LED
The UT-850N is equipped with LED indicators to show its status:
- Luz de potencia: Indicates that the device is powered on and connected to the USB port.
- RXD (Receive Data) Light: Flashes when data is being received by the converter from the RS-485/422 side.
- TXD (Transmit Data) Light: Flashes when data is being transmitted by the converter to the RS-485/422 side.

Imaxe 4.1: Primeiro plano view of the UT-850N showing the Power, RXD, and TXD LED indicators.
5. Mantemento
To ensure the longevity and optimal performance of your UOTEK UT-850N converter, follow these maintenance guidelines:
- Manter seco: Evite expoñer o dispositivo á humidade ou a líquidos.
- Limpar suavemente: Use a soft, dry cloth to clean the exterior. Do not use harsh chemicals or solvents.
- Control de temperatura: Operate and store the device within the specified temperature range (-20°C to 75°C).
- Coidado do cable: Avoid bending or kinking the cable excessively to prevent internal damage.
- Protección ESD: While the device has built-in ESD protection, always handle it with care, especially in dry environments, to minimize static discharge risks.
6 Solución de problemas
If you encounter issues with your UT-850N converter, consider the following:
- Sen luz de alimentación: Ensure the USB cable is securely connected to both the converter and the computer. Try a different USB port or computer.
- No Data Transmission (RXD/TXD not flashing):
- Verify all RS-485/422 wiring connections are correct according to the diagrams in Section 3.3.
- Check the baud rate settings on both your computer's serial port software and the connected industrial device. Ensure they match.
- Confirm that the industrial device is powered on and functioning correctly.
- For older operating systems, ensure the correct drivers are installed.
- Intermittent Connection/Data Errors:
- Check for electromagnetic interference (EMI) sources near the cable. Use shielded cables if necessary.
- Ensure the transmission distance does not exceed the specified limits (5,000m for RS-485/422, 5m for USB).
- Verify that the terminal resistors are correctly applied in RS-485/422 networks, especially for long distances or multi-point setups.
- Device Not Recognized by PC: Try connecting to a different USB port. Reinstall or update the USB serial port drivers if applicable.
7. Especificacións
| Característica | Especificación |
|---|---|
| Modelo | UT-850N |
| Estándares | USBV1.1, RS-485/422 EIA |
| USB Signal | VCC, DATOS+, DATOS-, GND, FG |
| Sinal RS-485 | T+, T-, GND |
| Sinal RS-422 | T+, T-, R+, R-, GND |
| Modo de traballo | Asynchronous, point-to-point/multipoint, 2-wire half-duplex or 4-wire full-duplex |
| Control de dirección | Automatic data flow direction control |
| Velocidade en baudios | 300-921.6Kbps (auto-detect) |
| Capacidade de carga | Up to 32 RS-422 or RS-485 devices |
| Distancia de transmisión | RS-485/422: 5,000m (at 9,600bps); USB: ≤ 5m |
| Protección portuaria | Surge, ±15KV ESD protection |
| Conectores | USB-A male, DB9 male |
| Medios de transmisión | Twisted-pair or shielded cable |
| Lonxitude do cable | 1.5 m |
| Temperatura de funcionamento | -20°C a 75°C |
| Humidade relativa | 5% a 95% (sen condensación) |
| SO compatible | Win Android/2000/2003/2008/2012/XP/Vista/7/8/8.1/10/CE, Mac, Linux |
| Peso do elemento | 5.5 onzas |
| Dimensións do paquete | 8.15 x 5.98 x 1.46 polgadas |
8. Garantía e soporte
For warranty information and technical support, please refer to the official UOTEK websitio web ou póñase en contacto co seu distribuidor autorizado. Garde o recibo de compra para reclamacións de garantía.





