Comprehensive Product Summary – U2485DB‑I Ground Isolator and Interface Converter

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### 1. Product Overview

Product Name: U2485DB‑I
Model: U2485DB‑I
Series: Universal RS‑232 / RS‑422 / RS‑485 Ground Isolated Converter Series
Article Number: U2485DBI
Manufacturer: Rayon Technology Co., Ltd.
Manufacturer Address: 2F, No. 177, Chung‑Shan 2 Rd., Lu‑Chou, New Taipei City, Taiwan
Contact:
- Tel: +886‑2‑82858362
- Fax: +886‑2‑82857065
- Email: rayon@ms1.hinet.net / info@rayontech.com.tw
- Website: [http://www.rayontech.com.tw](http://www.rayontech.com.tw)

Product Description:
The Rayon U2485DB‑I is a universal ground‑isolated serial communication converter designed to interface between RS‑232 and RS‑422/RS‑485 communication standards. It functions as a ground isolator, interface converter, repeater, or bridge, providing triple‑way isolation between input, output, and power circuits. The device is engineered for industrial and commercial serial communication environments where ground loops, stray currents, and electrical noise can degrade data integrity.

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### 2. Key Features

- Multi‑Function Serial Converter:
Operates as an RS‑232 to RS‑232 ground isolator, RS‑232 to RS‑422/RS‑485 converter, RS‑422/RS‑485 repeater, or RS‑422/RS‑485 bridge.

- Triple‑Way Isolation:
Provides galvanic isolation between input, output, and power supply circuits to eliminate ground loops and protect connected equipment from transient voltages and stray currents.

- Double‑Barrier Isolation:
Ensures robust signal separation between input and output connectors, enhancing reliability in electrically noisy environments.

- Flexible Interface Configuration:
Each port can be independently configured for RS‑422 (full‑duplex) or RS‑485 (half‑duplex) operation via a 4‑bit DIP switch.

- Auto‑Data‑Direction Control:
In RS‑485 mode, the converter automatically manages data direction without requiring additional software or control signals.

- LED Status Indicators:
Dedicated LEDs for power and data transmission (TX/RX) on each port provide real‑time communication status monitoring.

- Multiple Connection Modes:
Supports combinations such as RS‑232↔RS‑232, RS‑232↔RS‑422, RS‑232↔RS‑485, RS‑422↔RS‑422, RS‑422↔RS‑485, and RS‑485↔RS‑485.

- Compact Industrial Design:
Rugged metal enclosure with DB9 connectors for secure serial connections.

- Wide Power Input Range:
Operates from a 5 V DC supply (typical 400 mA) using an included 100–240 V AC adapter.

- Environmental Robustness:
Designed for operation in ambient temperatures from 0 °C to 55 °C and humidity up to 95 % RH.

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### 3. Technical Specifications

Physical Characteristics:
- Dimensions: 90 mm (W) × 150 mm (L) × 27 mm (H)
- Weight: Approx. 250 g (typical, excluding power adapter)
- Enclosure Material: Metal housing for EMI shielding and mechanical durability
- Color: Industrial gray finish

Electrical Characteristics:
- Power Supply: 5 V DC, 1000 mA (via UP110/UP220 adapter)
- Power Consumption: Typical 400 mA @ 5 V DC
- Adapter Input: 100–240 V AC, 50/60 Hz (US/EU plug types)

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

Connectors:
- Port A (RS‑232 Input): DB9 male
- Port B (RS‑232 Output): DB9 male
- Port C (RS‑422/RS‑485 Output): DB9 male
- Port D (RS‑422/RS‑485 Input): DB9 male

Interface Configuration:
- DIP Switch: 4‑bit switch for interface selection
- Bit 1 – Port A (RS‑232, not used)
- Bit 2 – Port B (RS‑232, not used)
- Bit 3 – Port C (ON = RS‑422, OFF = RS‑485)
- Bit 4 – Port D (ON = RS‑422, OFF = RS‑485)

Signal Pin Assignments (DB9):

| Pin | RS‑232 Signal | RS‑422/RS‑485 Signal |
|-----|----------------|----------------------|
| 1 | DCD (In) | — |
| 2 | RXD (In) | RXD+ (In) |
| 3 | TXD (Out) | TXD+ (Out) |
| 4 | DTR (Out) | TXD− (Out) |
| 5 | GND | GND |
| 6 | DSR (In) | RXD− (In) |
| 7 | RTS (Out) | — |
| 8 | CTS (In) | — |
| 9 | RI (In) | — |

RS‑485 Mode Notes:
- Pin 2 and 3 shorted as DATA+
- Pin 4 and 6 shorted as DATA−
- Supports 2‑wire RS‑485 operation
- Compatible with TB485 module for DB9‑to‑3‑pin terminal block conversion

LED Indicators:
- Power: DC power ON indicator
- AT/RX: RS‑232 Port A transmit/receive activity
- BT/RX: RS‑232 Port B transmit/receive activity
- CT/RX: RS‑422/RS‑485 Port C transmit/receive activity
- DT/RX: RS‑422/RS‑485 Port D transmit/receive activity

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### 4. Functionality

The U2485DB‑I serves as a versatile serial communication interface converter and isolator. It allows interconnection between devices using different serial standards while maintaining electrical isolation to prevent ground potential differences and interference.

Operating Modes:
1. RS‑232 ↔ RS‑232 Ground Isolator:
Provides galvanic isolation between two RS‑232 devices, protecting against ground loops.

2. RS‑232 ↔ RS‑422 Converter:
Converts RS‑232 signals to RS‑422 for long‑distance, full‑duplex communication.

3. RS‑232 ↔ RS‑485 Converter:
Enables RS‑232 devices to communicate within RS‑485 multi‑drop networks.

4. RS‑422 ↔ RS‑422 Repeater:
Extends communication distance for RS‑422 links by regenerating and isolating signals.

5. RS‑422 ↔ RS‑485 Converter:
Allows RS‑422 equipment to interface with RS‑485 networks.

6. RS‑485 ↔ RS‑485 Bridge:
Segments RS‑485 networks to increase node count and communication range.

Special Dual‑Function Modes:
- RS‑232 Isolator + RS‑232→RS‑422 Converter:
Simultaneous local RS‑232 and remote RS‑422 connections (poll‑and‑acknowledge environments only).
- RS‑232 Isolator + RS‑232→RS‑485 Converter:
Local RS‑232 and RS‑485 network connection under controlled communication timing.

Applications:
- Industrial automation and control systems
- Building management and HVAC systems
- SCADA and telemetry networks
- Serial device networking and data acquisition
- Laboratory instrumentation and test setups
- Long‑distance serial communication links

Compatibility:
- Compatible with standard RS‑232, RS‑422, and RS‑485 devices
- Works with PCs, PLCs, sensors, controllers, and serial modems
- Supports both 2‑wire (RS‑485) and 4‑wire (RS‑422) configurations

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### 5. Components & Accessories

Included Components:
- U2485DB‑I converter unit
- UP110/UP220 power adapter (100–240 V AC → 5 V DC 1 A)
- User manual

Optional Accessories:
- TB485 Module: DB9 female to RS‑485 3‑pin terminal block adapter for 2‑wire RS‑485 wiring.
- Related Products (Performance Upgrade Options):
- UCON301‑I: Single‑port RS‑232/RS‑422/RS‑485 to ground‑isolated RS‑422/RS‑485 converter
- UCON232DB‑I: Triple‑way ground‑isolated RS‑232 to RS‑232 isolator
- UCON422DB‑I: Ground‑isolated RS‑422/RS‑485 repeater and bridge
- UCON485DB‑I: Ground‑isolated RS‑232 to RS‑422/RS‑485 converter
- RS4232‑4: Four‑channel RS‑232 to isolated RS‑232/RS‑422/RS‑485 converter box
- RS4232‑8: Eight‑channel RS‑232 to isolated RS‑422/RS‑485 converter box

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### 6. Installation & Setup

Power Requirements:
- Connect the supplied 5 V DC adapter to the power input jack.
- Verify the Power LED is illuminated before connecting communication cables.

Mounting Options:
- Desktop placement or panel mounting (optional brackets available).
- Ensure adequate ventilation and avoid exposure to moisture or excessive vibration.

Configuration Procedure:
1. Set DIP Switches:
- Determine desired interface type for ports C and D (RS‑422 or RS‑485).
- Set DIP switch bits accordingly (ON = RS‑422, OFF = RS‑485).
2. Connect Serial Cables:
- Use DB9 male connectors for RS‑232 and RS‑422/RS‑485 ports.
- For RS‑485 2‑wire operation, use TB485 adapter if required.
3. Power On:
- Apply power and verify LED indicators for correct operation.
4. Test Communication:
- Confirm data transmission via TX/RX LEDs on active ports.

Safety Notes:
- Always power off before changing DIP switch settings.
- Avoid connecting multiple ground references to prevent potential differences.
- Use shielded cables for long‑distance or high‑noise environments.

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### 7. Performance & Capabilities

Transmission Modes:
- RS‑422: Full‑duplex, 4‑wire differential signaling
- RS‑485: Half‑duplex, 2‑wire differential signaling with automatic direction control

Isolation Characteristics:
- Triple Isolation: Input ↔ Output ↔ Power
- Isolation Type: Opto‑isolation and galvanic separation
- Purpose: Prevents ground loops, surge currents, and EMI interference

Data Transmission:
- Typical Baud Rate Support: Up to 115.2 kbps (standard RS‑232/RS‑485 rates)
- Signal Integrity: Maintained over extended cable lengths (up to 1200 m for RS‑422/RS‑485)
- Auto‑Direction Control: Eliminates need for RTS/CTS control in RS‑485 mode

Efficiency & Reliability:
- Low power consumption (400 mA typical)
- Stable operation across wide environmental conditions
- LED diagnostics for quick troubleshooting

Limitations:
- RS‑232 and RS‑422/RS‑485 outputs should not transmit simultaneously in dual‑output configurations (to avoid data collision).
- Designed for “poll‑and‑acknowledge” communication in mixed‑mode applications.

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### 8. Standards & Compliance

Electrical and Communication Standards:
- Complies with EIA/TIA‑232‑E, EIA/TIA‑422‑B, and EIA/TIA‑485‑A standards
- Supports standard asynchronous serial communication protocols

Safety and Environmental Compliance:
- Designed to meet CE and FCC Class A electromagnetic compatibility requirements (typical for industrial communication devices)
- RoHS‑compliant construction (lead‑free components)
- Conforms to IEC isolation and surge protection guidelines for industrial serial converters

Quality Assurance:
- Manufactured under Rayon Technology’s ISO‑certified quality management system
- 100 % functional testing prior to shipment

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### 9. Additional Information

Warranty:
Standard manufacturer’s warranty (typically one year) covering defects in materials and workmanship under normal use.

Technical Support:
Rayon Technology provides email and phone support for configuration, troubleshooting, and integration assistance.

Maintenance:
- Periodically inspect connectors and cables for wear or corrosion.
- Keep ventilation openings clear of dust.
- No internal user‑serviceable components; return to authorized service center for repair.

Firmware & Updates:
The U2485DB‑I operates as a hardware‑based converter and does not require firmware updates or driver installation. It functions transparently to connected devices.

Product Lifecycle & Compatibility:
Fully compatible with existing Rayon UCON and RS4232 series converters, ensuring scalability and interoperability within multi‑port serial communication systems.

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### Summary

The Rayon U2485DB‑I is a high‑performance, industrial‑grade ground‑isolated serial converter designed for flexible interfacing between RS‑232, RS‑422, and RS‑485 communication standards. Its triple‑way isolation, multi‑mode configurability, and auto‑direction control make it ideal for complex serial communication networks requiring electrical protection and signal integrity. With its compact form factor, robust construction, and versatile functionality, the U2485DB‑I simplifies system design by combining the roles of isolator, converter, repeater, and bridge into a single, reliable device.