Comprehensive Product Summary – UTS004 USB 2.0 to Isolated 4×RS485/422 Converter

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### 1. Product Overview

Product Name: USB 2.0 to Isolated 4×RS485/422 Converter
Model: UTS004
Series: UTS400 Series – USB to Serial Port Converter Family
Article Number: UTS004
Manufacturer: Rayon Technology Co., Ltd.
Manufacturer Address: 2F, No. 177, Chung-Shan 2 Rd., Lu-Chou City, Taipei Hsien, Taiwan
Contact:
- Tel: +886-2-82858362
- Fax: +886-2-82857065
- Email: rayon@ms1.hinet.net
- Web: [www.rayontech.com](http://www.rayontech.com) / [www.computex.com.tw/rayon](http://www.computex.com.tw/rayon)

Product Description:
The Rayon UTS004 is a high-performance USB 2.0 to isolated 4-port RS485/RS422 converter designed for industrial, automation, and communication applications requiring multiple isolated serial interfaces. It integrates four independent, ground-isolated RS422/RS485 ports within a compact, metal-encased module. The device uses the MOSCHIP MCS7840 USB-to-serial controller, providing robust data handling with 512-byte FIFO buffers per port and full USB 2.0 compliance. The UTS004 is bus-powered via USB (5VDC, 400mA) and supports LED indicators for power and data activity on each channel.

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### 2. Key Features

- Four Independent Serial Ports:
Provides four isolated RS422/RS485 ports (Ports A, B, C, D) in a single enclosure, enabling simultaneous multi-channel communication.

- Full Electrical Isolation:
Each port is galvanically isolated from the others and from the USB bus, ensuring signal integrity and protection against ground loops and electrical noise.

- Flexible Interface Configuration:
Each port can be configured as RS422 or RS485 via DIP switch selection, allowing flexible deployment in various serial communication environments.

- Auto Data Direction Control (RS485 Mode):
Automatically manages data direction in RS485 mode, eliminating the need for manual RTS signal control and simplifying half-duplex communication.

- High-Performance USB 2.0 Controller:
Utilizes the MOSCHIP MCS7840 chipset, supporting USB 2.0 full-speed operation and backward compatibility with USB 1.1 hosts.

- Large FIFO Buffers:
Each serial port includes a 512-byte FIFO buffer for efficient data transfer and reduced CPU overhead.

- LED Indicators per Channel:
Dedicated LEDs for each port indicate transmit/receive activity (TXD/RXD) and power status, providing clear visual diagnostics.

- Bus-Powered Operation:
Draws power directly from the USB bus (5VDC, 400mA), eliminating the need for an external power supply. Optional self-powered version (UTS004S) available for standalone operation.

- Compact and Durable Metal Enclosure:
Rugged 90 × 150 × 27 mm metal housing ensures durability and EMI shielding, suitable for industrial environments.

- Plug-and-Play USB Interface:
Supports hot-plugging and automatic detection by modern operating systems. Compatible with Windows, Linux, and other USB-compliant systems.

- iSerial Feature Support (via MCS7840):
When programmed with a unique EEPROM serial number, the device retains consistent COM port assignments across different USB ports, simplifying system integration.

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### 3. Technical Specifications

Physical Characteristics:
- Dimensions: 90 mm (W) × 150 mm (L) × 27 mm (H)
- Weight: Approx. 300–400 g (metal enclosure)
- Enclosure Material: Metal (EMI-shielded, industrial-grade)
- Color: Metallic silver/gray finish

USB Interface:
- Connector Type: USB Type-B female
- Standard Compliance: USB 2.0 (Full-Speed, 12 Mbps)
- Controller IC: MOSCHIP MCS7840
- FIFO Buffer: 512 bytes per serial port
- Power Source: USB bus-powered (5VDC, 400mA typical)
- Optional Power Mode: Self-powered (UTS004S variant, 5VDC external adapter)

Serial Interface (RS422/RS485):
- Connector Type: DB9 male (x4)
- Number of Ports: 4 (A, B, C, D)
- Interface Type: Selectable RS422 or RS485 (via DIP switch)
- Signal Pins per Port: TX+, TX−, RX+, RX−, Isolated GND
- Isolation: Each port isolated from others and from USB ground
- Auto Data Direction Control: Supported in RS485 mode
- Data+ / Data− Mapping: TX+/TX− or RX+/RX− pairs configurable for RS485 operation

Power Requirements:
- Input Voltage: 5VDC (from USB bus)
- Current Consumption: 400mA typical
- Optional External Power: 5VDC adapter (for UTS004S self-powered model)

Environmental Conditions:
- Operating Temperature: 0°C to 55°C
- Storage Temperature: 0°C to 65°C
- Operating Humidity: 10% to 95% RH (non-condensing)
- Storage Humidity: 5% to 95% RH (non-condensing)

LED Indicators:
- PWR: Power ON indicator
- ATRD: Port A TXD/RXD activity
- BTRD: Port B TXD/RXD activity
- CTRD: Port C TXD/RXD activity
- DTRD: Port D TXD/RXD activity

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### 4. Functionality

Operational Overview:
The UTS004 functions as a USB-to-multi-serial converter, bridging a host computer’s USB interface to four isolated RS422/RS485 serial channels. It enables communication with industrial devices such as PLCs, sensors, motor controllers, and data acquisition systems that use differential serial signaling.

How It Works:
Upon connection to a USB port, the MCS7840 controller enumerates as four virtual COM ports on the host system. Each port operates independently, supporting full-duplex RS422 or half-duplex RS485 communication. DIP switches allow users to select the desired interface type per port. The Auto Data Direction Control feature automatically manages transmit and receive line switching in RS485 mode, ensuring seamless data flow without software intervention.

Use Cases and Applications:
- Industrial automation and process control
- Building management systems (BMS)
- SCADA and telemetry systems
- Data acquisition and instrumentation
- Serial device networking and monitoring
- Redundant communication setups requiring isolation
- Laboratory and test equipment interfacing

Compatibility:
- Operating Systems: Windows (XP, 7, 8, 10, 11), Linux, macOS (with appropriate drivers)
- USB Standards: Fully compliant with USB 2.0 specification; backward compatible with USB 1.1
- Serial Protocols: RS422 (full-duplex), RS485 (half-duplex, multi-drop)

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### 5. Components & Accessories

Included Items:
- UTS004 Converter Unit (metal enclosure)
- U101 USB Cable (6 ft, USB Type-A to Type-B)
- User documentation and driver support (available online)

Optional Accessories:
- External 5VDC power adapter (for UTS004S self-powered version)
- Mounting brackets or DIN-rail adapters (optional, depending on installation environment)
- Replacement USB cables or DB9 serial cables

Connectors:
- USB Port: Type-B female (host connection)
- Serial Ports: Four DB9 male connectors (RS422/RS485)

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### 6. Installation & Setup

Requirements:
- Available USB 2.0 or 1.1 port on host computer
- Supported operating system with appropriate driver installed
- Optional external power supply (for self-powered variant)

Installation Steps:
1. Connect the UTS004 to the host computer using the provided USB cable.
2. Install the driver software (if required) to enable virtual COM ports.
3. Configure each port’s interface type (RS422 or RS485) using the DIP switches.
4. Connect serial devices to the DB9 ports using appropriate cabling.
5. Verify LED indicators for power and data activity.
6. Begin communication through the assigned COM ports.

Mounting Options:
- Desktop placement (standard)
- Optional wall or DIN-rail mounting (with accessories)

Configuration:
- DIP switch selection for RS422/RS485 mode per port
- Auto Data Direction Control automatically manages RS485 transmission direction
- iSerial feature (if EEPROM programmed) ensures consistent COM port numbering

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### 7. Performance & Capabilities

Data Throughput:
- USB 2.0 full-speed (12 Mbps) interface ensures efficient data transfer between host and serial devices.
- Each serial port supports high-speed communication (up to 921.6 kbps, depending on driver and system configuration).

Buffering:
- 512-byte FIFO per port minimizes data loss and ensures smooth communication under heavy load.

Isolation Performance:
- Each port is galvanically isolated, preventing ground potential differences and protecting connected equipment from electrical surges or noise interference.

Efficiency:
- Bus-powered design reduces cabling complexity and power supply requirements.
- Auto Data Direction Control enhances RS485 communication efficiency by eliminating manual RTS control.

Limitations:
- Total current draw limited to 400mA from USB bus; high-load configurations may require self-powered version.
- Operating temperature limited to 55°C; not suitable for extreme industrial environments without additional cooling.

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### 8. Standards & Compliance

Electrical and Interface Standards:
- USB 2.0 (Full-Speed)
- EIA/TIA-422 (RS422)
- EIA/TIA-485 (RS485)

Safety and Isolation:
- Ground isolation between ports and USB interface
- Designed for industrial-grade signal integrity and protection

Regulatory Compliance:
- CE and FCC compliance (typical for Rayon USB converters)
- RoHS-compliant materials and manufacturing processes

Chipset Compliance:
- MOSCHIP MCS7840 conforms to USB-IF specifications
- Supports iSerial feature for unique device identification via EEPROM

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### 9. Additional Information

Warranty:
- Standard manufacturer warranty (typically 1 year, subject to regional terms)
- Covers defects in materials and workmanship under normal use

Technical Support:
- Provided by Rayon Technology Co., Ltd. via email and web resources
- Driver downloads, firmware updates, and documentation available online

Maintenance:
- No routine maintenance required
- Keep connectors clean and free from dust
- Avoid exposure to moisture or extreme temperatures

Firmware & Driver Updates:
- Updated drivers available for Windows and Linux platforms
- EEPROM programming available for iSerial feature customization

Related and Compatible Products:
- UTS400: USB to 4×RS232 (non-isolated)
- UTS040: USB to 4×Isolated RS232
- UTS485: USB to 2×RS232 + 2×Isolated RS422/485
- UTS134 / UTS134i: USB to 4×RS422/485 (non-isolated / isolated)
- TWIN485: Dual-port isolated RS232 to RS422/485 converter

Model Selection Guide (Excerpt):
| Model | RS232 | Isolated RS232 | RS422/485 | Isolated RS422/485 | Total Ports |
|--------|--------|----------------|------------|--------------------|--------------|
| UTS400 | 4 | 0 | 0 | 0 | 4 |
| UTS040 | 0 | 4 | 0 | 0 | 4 |
| UTS004 | 0 | 0 | 0 | 4 | 4 |
| UTS485 | 2 | 0 | 0 | 2 | 4 |
| UTS134i | 0 | 0 | 0 | 4 | 4 |

Revision Information:
- Document Revision: 1.1 (Preliminary)
- Date: August 7, 2006

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### Summary

The Rayon UTS004 USB 2.0 to Isolated 4×RS485/422 Converter is a robust, industrial-grade communication interface designed to expand a computer’s serial connectivity through a single USB port. Featuring four fully isolated RS422/RS485 channels, the UTS004 ensures reliable, noise-free data transmission in demanding environments. Its MOSCHIP MCS7840 controller provides high-speed USB 2.0 performance, large FIFO buffers, and advanced features such as Auto Data Direction Control and iSerial support. The converter’s compact metal enclosure, LED diagnostics, and plug-and-play operation make it an ideal solution for industrial automation, SCADA, and instrumentation systems requiring multiple isolated serial interfaces.

With its combination of flexibility, electrical isolation, and ease of integration, the UTS004 stands as a versatile and dependable choice for engineers and system integrators seeking a high-quality USB-to-serial communication solution.