Comprehensive Product Summary – UTS301 USB 2.0 to 3×RS232 and Isolated 1×RS485/422 Converter

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### 1. Product Overview

Product Name: USB 2.0 to 3×RS232 and Isolated 1×RS485/422 Converter
Model: UTS301
Series: UTS400 Series – USB to Serial Port Converter Family
Article Number: UTS301
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)

Product Description:
The Rayon UTS301 is a high-performance USB 2.0 to multi-serial converter designed to provide three standard RS232 ports and one isolated RS485/RS422 port within a single compact metal enclosure. It enables seamless communication between USB-enabled host systems and multiple serial devices, offering robust electrical isolation, flexible configuration, and reliable data transfer. The UTS301 is part of Rayon’s UTS400 series, which includes a range of USB-to-serial converters supporting various combinations of RS232, RS422, and RS485 interfaces.

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### 2. Key Features

- Multi-Port Design: Provides four independent serial communication ports in one module — three RS232 ports and one isolated RS485/RS422 port.
- USB 2.0 Interface: Fully compliant with USB 2.0 specifications, ensuring high-speed data transfer and backward compatibility with USB 1.1.
- MOSCHIP MCS7840 Controller: Utilizes the MCS7840 USB-to-serial bridge chip, offering stable performance, integrated FIFO buffers, and support for multiple serial channels.
- 512-Byte FIFO per Port: Each serial port includes a 512-byte FIFO buffer to enhance data throughput and minimize latency during high-speed communication.
- Electrical Isolation: The RS485/RS422 port is galvanically isolated, providing protection against ground loops and electrical noise in industrial environments.
- Auto Data Direction Control (RS485): Automatically manages data direction in RS485 mode, simplifying configuration and ensuring reliable half-duplex communication.
- LED Indicators: Individual LED indicators for each port (A, B, C, D) display transmit/receive activity, along with a dedicated power LED for system status monitoring.
- Bus-Powered Operation: Draws power directly from the USB bus (5VDC, 400mA), eliminating the need for an external power supply.
- Compact Metal Enclosure: Durable metal housing (90 × 150 × 27 mm) provides mechanical protection and effective EMI shielding.
- Flexible Configuration: RS422 or RS485 mode selectable via DIP switch; supports both 4-wire (RS422) and 2-wire (RS485) configurations.
- Hot-Pluggable USB Interface: Supports plug-and-play installation without requiring system reboot.
- iSerial Feature Support: When programmed with a unique EEPROM serial number, the MCS7840 chip retains consistent COM port assignments across different USB ports.
- Wide Environmental Tolerance: Designed for industrial and commercial environments with operating temperature range from 0°C to 55°C and humidity up to 95% RH.

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### 3. Technical Specifications

Physical Dimensions:
- Width: 90 mm
- Length: 150 mm
- Height: 27 mm

Weight:
- Approx. 300–400 g (typical, including metal enclosure)

Enclosure Material:
- Metal case for durability and EMI protection

USB Interface:
- Connector Type: USB Type-B female
- Standard: USB 2.0 (compatible with USB 1.1)
- Controller: MOSCHIP MCS7840
- FIFO Buffer: 512 bytes per serial port
- Power Source: USB bus powered (5VDC, 400mA typical)

Serial Port Interface:
- Connector Type: DB9 male connectors (4 total)
- Interface Types:
- 3 × RS232 ports
- 1 × isolated RS485/RS422 port
- Isolation: Galvanic isolation on RS485/RS422 channel
- Signal Pins (RS422/RS485): TX+, TX−, RX+, RX−, isolated GND
- RS485 Mode: Auto Data Direction Control supported
- RS422/RS485 Selection: Configurable via DIP switch
- RS485 2-Wire Mode: TX+/RX+ shorted as DATA+, TX−/RX− shorted as DATA−

Power Requirements:
- Input Voltage: 5VDC (from USB bus)
- Current Consumption: 400mA typical
- Optional Self-Powered Version: UTS400S (supports external 5VDC adapter)

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)

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### 4. Functionality

Operating Principle:
The UTS301 functions as a USB-to-multi-serial bridge, converting USB data streams into asynchronous serial communication signals. The integrated MCS7840 controller manages data flow between the host computer and the serial ports, ensuring efficient buffering and protocol handling. Each serial port operates independently, allowing simultaneous communication with multiple devices.

Use Cases and Applications:
- Industrial automation and control systems
- Point-of-Sale (POS) terminals and kiosks
- Data acquisition and instrumentation
- Serial device networking and monitoring
- Communication with PLCs, sensors, and modems
- Integration with barcode scanners, printers, and legacy serial equipment

Compatibility:
- Compatible with Windows, Linux, and macOS operating systems supporting USB CDC or vendor-specific drivers.
- Works with standard serial communication software and terminal emulators.
- Supports hot-plugging and automatic COM port assignment.

Interface Configuration:
- RS422 or RS485 mode selectable via internal DIP switch.
- RS485 mode supports automatic direction control, eliminating the need for manual RTS signal management.
- Each port can be independently monitored via LED indicators for TX/RX activity.

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### 5. Components & Accessories

Included Items:
- UTS301 converter module (metal enclosure)
- USB cable (Model U101): 6-foot USB Type-A to Type-B cable
- User documentation and driver CD (depending on shipment configuration)

Optional Accessories:
- External 5VDC power adapter (for self-powered variant UTS400S)
- Mounting brackets or DIN-rail adapters (optional, depending on installation requirements)

Connectors:
- USB Port: Type-B female
- Serial Ports: Four DB9 male connectors (Ports A, B, C, D)
- LED Indicators:
- PWR: Power ON indicator
- ATRD: RS232 Port A TXD/RXD activity
- BTRD: RS232 Port B TXD/RXD activity
- CTRD: RS232 Port C TXD/RXD activity
- DTRD: RS485/RS422 Port D TXD/RXD activity

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### 6. Installation & Setup

System Requirements:
- Host computer with available USB 2.0 or higher port
- Supported operating system (Windows, Linux, macOS)
- Driver installation (if required by OS)

Installation Steps:
1. Connect the UTS301 to the host computer using the supplied USB cable.
2. The operating system will detect the new USB-to-serial device.
3. Install the appropriate driver if prompted (Rayon or MOSCHIP MCS7840 driver).
4. Verify COM port assignments in the system device manager.
5. Connect serial devices to the DB9 ports as required.
6. Configure RS422/RS485 mode using the DIP switch if necessary.
7. Observe LED indicators to confirm communication activity.

Mounting Options:
- Desktop placement (standard)
- Optional wall or DIN-rail mounting (using accessory kits)

Configuration Notes:
- RS422/RS485 selection is made via DIP switch located inside the enclosure.
- RS485 mode automatically manages data direction; no manual RTS control required.
- For RS485 2-wire operation, TX+/RX+ and TX−/RX− are internally shorted.

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### 7. Performance & Capabilities

Data Transfer Rate:
- Supports standard asynchronous serial data rates up to 921.6 kbps (typical for MCS7840-based converters).

Buffering:
- 512-byte FIFO per port ensures smooth data flow and minimizes overrun errors.

Throughput:
- Capable of simultaneous multi-port operation without data loss under typical USB 2.0 bandwidth conditions.

Latency:
- Low-latency communication suitable for real-time control and monitoring applications.

Isolation Performance:
- RS485/RS422 port provides galvanic isolation to protect host and connected devices from voltage surges and ground potential differences.

Power Efficiency:
- Operates entirely from USB bus power (400mA @ 5VDC), eliminating external power requirements for most applications.

Limitations:
- Total current draw limited by USB port capacity; external power recommended if connected devices require additional power.
- RS422/RS485 configuration requires internal DIP switch access.

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### 8. Standards & Compliance

Electrical and Interface Standards:
- USB 2.0 (Full-Speed and High-Speed compliant)
- EIA/TIA RS232, RS422, and RS485 standards
- Auto Data Direction Control compliant with RS485 half-duplex operation

Regulatory Compliance:
- CE and FCC compliance (typical for Rayon industrial communication products)
- RoHS compliant materials and manufacturing processes

Industry Standards:
- Compatible with standard serial communication protocols (Modbus RTU, ASCII, etc.)
- Supports standard DB9 pin assignments for RS232 and RS422/RS485 interfaces

iSerial Feature (MCS7840):
- Supports unique serial number programming in EEPROM for consistent COM port assignment across different USB ports.
- Prevents reassignment of COM numbers when device is connected to alternate USB ports on the same host system.

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### 9. Additional Information

Warranty:
- Standard manufacturer warranty (typically 1 year, depending on region and distributor policy).

Technical Support:
- Provided by Rayon Technology Co., Ltd. via email and telephone.
- Driver updates and documentation available on the official website.

Maintenance:
- No periodic maintenance required.
- Keep connectors clean and free from dust.
- Avoid exposure to excessive heat or moisture.

Firmware & Driver Updates:
- Updated drivers and utilities available from Rayon or MOSCHIP support pages.
- EEPROM programming for iSerial feature can be performed using MOSCHIP configuration tools.

Product Family Context:
The UTS301 belongs to the UTS400 series, which includes multiple models offering different combinations of RS232, RS422, and RS485 interfaces. Examples include:
- UTS400: 4×RS232
- UTS004: 4×Isolated RS422/RS485
- UTS031: 3×Isolated RS232 + 1×Isolated RS485
- UTS301: 3×RS232 + 1×Isolated RS485/RS422 (this model)
- UTS310: 3×RS232 + 1×Isolated RS232

This modular approach allows users to select the optimal configuration for their specific application, balancing cost, isolation, and interface flexibility.

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### Summary

The Rayon UTS301 USB 2.0 to 3×RS232 and Isolated 1×RS485/422 Converter is a robust, industrial-grade communication interface designed for users requiring multiple serial connections through a single USB port. Featuring the reliable MOSCHIP MCS7840 controller, 512-byte FIFO buffers, and galvanic isolation on the RS485/RS422 channel, it ensures stable and interference-free data transmission. Its compact metal housing, LED indicators, and plug-and-play USB interface make it ideal for industrial automation, POS systems, and instrumentation applications. With flexible configuration options, compliance with major communication standards, and support for the iSerial feature, the UTS301 delivers both performance and convenience in demanding serial communication environments.