Waveshare Industrial USB to RS485 Converter User Manual

Introduction

This manual provides comprehensive instructions for the Waveshare Industrial USB to RS485 Converter. This device is designed for stable and reliable bidirectional communication, making it suitable for industrial control equipment and applications requiring high communication performance. It features original FT232RL and SP485EEN chips, along with robust protection circuits.

Key Features

• Original FT232RL and SP485EEN Chips: Ensures stable, fast communication and better compatibility.
• TVS (Transient Voltage Suppressor): Effectively suppresses surge voltage and transient spike voltage, providing lightning-proof and anti-electrostatic protection.
• Resettable Fuse and Protection Diodes: Guarantees stable current/voltage outputs, offers over-current/over-voltage protection, and improves shock resistance.
• Long Transmission Distance: Supports RS485 transmission up to 1.2km and USB up to 5 meters, with a reliable speed of 300-921600bps.
• Multi-System Support: Compatible with Linux, Android, WinCE, Windows 11/10/8.1/8/7/XP, and Mac operating systems.
• LED Indicators: Three LEDs (PWR, TXD, RXD) for indicating power and transceiver status.

Product Overview

The Waveshare Industrial USB to RS485 Converter is a compact and robust device designed for reliable serial communication. Below are its main components and their functions.

Image: Overview of the USB to RS485 converter, highlighting its industrial-grade design, bidirectional transmission, 600W lightning/anti-surge protection, 1.2km RS485 transmission distance, and TVS (Transient Voltage Suppressor).

Internal Components

Image: Detailed internal view of the converter, showing the FT232RL chip, SP485EEN chip, TVS Protection Circuit, Resettable Fuse, ESD Protection Circuit, and 120R Terminal Resistor.

LED Indicators

Image: The converter showing its three LED indicators (PWR, TXD, RXD) and their functions. PWR lights up red when power is connected. TXD blinks red during data transmission. RXD blinks red during data reception. The image also includes outline dimensions in millimeters.

• PWR (Power): Red LED, indicates power connection.
• TXD (Transmit Data): Red LED, blinks when data is being transmitted from the USB port.
• RXD (Receive Data): Red LED, blinks when data is being received by the device.

Setup and Connection

Driver Installation

The Waveshare USB to RS485 Converter utilizes the FT232RL chip, which typically requires a driver for proper operation on some systems. While many modern operating systems may install a generic driver automatically, it is recommended to install the official FTDI drivers for optimal performance and compatibility.

1. Download Drivers: Visit the official FTDI website (ftdichip.com/drivers/) to download the latest VCP (Virtual COM Port) drivers compatible with your operating system (Windows, macOS, Linux, Android, WinCE).
2. Install Drivers: Follow the installation instructions provided by FTDI for your specific operating system.
3. Connect Device: Plug the USB end of the converter into an available USB port on your computer.
4. Verify Installation: After installation, check your device manager (Windows) or equivalent system utility to ensure the converter is recognized as a Virtual COM Port.

RS485 Wiring

The converter provides a screw terminal block for RS485 connections. Ensure correct polarity for communication.

• A+: Connect to the A+ terminal of your RS485 device.
• B-: Connect to the B- terminal of your RS485 device.
• GND: Connect to the Ground terminal of your RS485 device (optional, but recommended for stable communication over longer distances or in noisy environments).

Image: An example setup showing two USB to RS485 converters connected for testing. One converter is connected to a host PC via USB, and its A+ and B- terminals are wired to the A+ and B- terminals of a second converter, demonstrating a basic RS485 communication link.

Operating Instructions

Once the drivers are installed and the device is connected, you can use serial communication software to interact with your RS485 devices.

1. Identify COM Port: In your computer's Device Manager (Windows) or equivalent, identify the assigned COM port number for the "USB Serial Port" (e.g., COM3, COM4).
2. Open Serial Terminal Software: Use any standard serial terminal software (e.g., PuTTY, RealTerm, Tera Term, or custom applications) to open the identified COM port.
3. Configure Settings: Configure the serial port settings to match your RS485 device's requirements. Common settings include:
   • Baud Rate: 300-921600bps (e.g., 9600, 19200, 115200)
   • Data Bits: 8
   • Parity: None
   • Stop Bits: 1
   • Flow Control: None
4. Initiate Communication: Send and receive data as per your RS485 device's protocol. Observe the TXD and RXD LEDs on the converter to confirm data transmission and reception.

Multi-System Compatibility

Image: A visual representation of the multi-system support, showing logos for Windows, Mac, Linux, and Android operating systems, indicating broad compatibility.

This converter supports a wide range of operating systems, including Mac, Linux, Android, WinCE, and various Windows versions (11/10/8.1/8/7/XP). Driver installation procedures may vary slightly between operating systems.

Technical Specifications

Image: A table detailing the product parameters, including product type, baudrate, host port, device port, USB specifications (operating voltage, connector, protection, transmission distance), RS485 specifications (connector, pins, direction control, protection, transmission distance, transmission mode), LED indicators, operating environment, and operating system support.

Dimensions

Image: A detailed diagram showing the physical dimensions of the USB to RS485 converter in millimeters.

Troubleshooting

• Device Not Recognized:
  • Ensure FTDI drivers are correctly installed. Refer to the "Driver Installation" section.
  • Try connecting to a different USB port on your computer.
  • Test with a different USB cable if using an extension.
• No Data Transmission/Reception (LEDs not blinking):
  • Verify RS485 wiring: Ensure A+ is connected to A+ and B- to B-. Reversed polarity is a common issue.
  • Check serial port settings (baud rate, data bits, parity, stop bits) in your software to match the RS485 device.
  • Confirm the RS485 device is powered on and functioning correctly.
  • Ensure only one master device is attempting to communicate on the RS485 bus at a time.
• Intermittent Communication:
  • Check for loose wiring connections at the screw terminal.
  • Consider adding a GND connection if not already used, especially over longer distances.
  • Ensure the RS485 bus is properly terminated if required by your setup (the converter has an onboard 120R balancing resistor, but external termination might be needed for the bus itself).
  • Reduce cable length or use shielded cables in noisy environments.
• Driver Issues on Windows 11/10:
  • Sometimes Windows Update might overwrite the official FTDI driver with a generic one. Reinstall the official FTDI VCP drivers from the FTDI website.

Maintenance

• Cleaning: Keep the device clean and free from dust. Use a soft, dry cloth for cleaning. Avoid liquid cleaners.
• Storage: Store the converter in a dry, cool environment away from direct sunlight and extreme temperatures.
• Handling: Handle the device with care to prevent physical damage to the USB connector or screw terminals.
• Firmware Updates: This device typically does not require user-updatable firmware. Ensure your operating system drivers are up to date for best performance.

Warranty and Support

For warranty information and technical support, please refer to the Waveshare official website or contact your point of purchase. Keep your purchase receipt for warranty claims.