Comprehensive Product Summary – Rayon Technology S434io Serial Port Sharer

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### 1. Product Overview

Product Name: S434io
Model: S434io
Series: S400 Series – Serial Port Sharer
Article Number: S434io
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
- Websites: [www.rayontech.com](http://www.rayontech.com), [www.computex.com.tw/rayon](http://www.computex.com.tw/rayon)

Product Type: Ground-isolated serial port sharer for RS422/RS485 communication networks.
Intended Use: Enables one master RS422/485 port to communicate with up to three isolated RS422/485 slave ports simultaneously, providing electrical isolation and signal integrity in industrial and automation environments.

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### 2. Key Features

- One-to-Three Port Sharing:
The S434io allows a single master RS422/485 port (Port A) to communicate with three independent, isolated RS422/485 slave ports (Ports B, C, and D). Data from the master is broadcast to all slaves simultaneously, while responses from any slave are directed only to the master.

- Full Electrical Isolation:
Both the master and slave ports are galvanically isolated, ensuring protection against ground loops, electrical noise, and potential differences between connected devices. This isolation enhances system reliability in electrically noisy or distributed environments.

- Dual Ground Isolation:
The device supports double ground isolation—between the external devices and the S434io unit, and between each external device connected to the slave ports. This feature is critical for industrial automation systems where multiple devices may operate on different ground potentials.

- RS422/RS485 Interface Flexibility:
Each port can be configured as RS422 or RS485 via DIP switch settings. This flexibility allows the S434io to adapt to various serial communication standards and system architectures.

- Auto Data Direction Control (RS485 Mode):
In RS485 mode, the S434io automatically manages data direction control, eliminating the need for manual RTS signal handling. TX+ and RX+ lines are shorted as DATA+, and TX– and RX– lines as DATA–, simplifying wiring and configuration.

- LED Status Indicators:
Four independent TX/RX activity LEDs (ATRX, BTRX, CTRX, DTRX) provide real-time communication status for each port, along with a dedicated power indicator (PWR).

- Compact and Robust Design:
The unit’s compact aluminum enclosure (90 × 150 × 27 mm) is designed for industrial environments, offering durability and ease of installation.

- Universal Power Input:
Operates with a 100–240 VAC input power adapter, outputting 5 VDC at 1000 mA. The device consumes approximately 400 mA at 5 VDC.

- Wide Environmental Tolerance:
Designed for operation in ambient temperatures from 0°C to 55°C and humidity levels from 10% to 95% RH, making it suitable for a wide range of industrial and field applications.

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### 3. Technical Specifications

| Parameter | Specification |
|----------------|-------------------|
| Model | S434io |
| Series | S400 Series |
| Interface Type | Isolated RS422/RS485 |
| Number of Ports | 4 (1 Master + 3 Slaves) |
| Connector Type | DB9 Male (Ports A, B, C, D) |
| Signal Pins per Port | TX+, TX–, RX+, RX–, Isolated GND |
| RS485 Mode Configuration | TX+/RX+ shorted as DATA+, TX–/RX– shorted as DATA– |
| Isolation | Ground isolation between all ports and between external devices |
| Auto Data Direction Control | Supported in RS485 mode |
| Power Input | 100–240 VAC (via UP110/UP220 adapter) |
| Power Output (Adapter) | 5 VDC, 1000 mA |
| Power Consumption | 400 mA @ 5 VDC |
| LED Indicators | PWR, ATRX, BTRX, CTRX, DTRX |
| Dimensions (W × L × H) | 90 mm × 150 mm × 27 mm |
| 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 |
| Enclosure Material | Industrial-grade metal (Rayon standard housing) |
| Mounting | Desktop or panel mounting (optional brackets) |
| Weight | Approx. 250–300 g (typical for S400 series) |

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### 4. Functionality

Operational Principle:
The S434io acts as a serial data distribution and collection hub. It connects one master device (e.g., PLC, PC, or data logger) to three isolated slave devices (e.g., sensors, meters, controllers) using RS422 or RS485 communication standards.

- Data Flow:
- Data transmitted from the master port (Port A) is simultaneously broadcast to all three slave ports (Ports B, C, D).
- Data received from any slave port is directed exclusively to the master port, preventing cross-communication between slaves.

- Isolation Function:
Each port is galvanically isolated, ensuring that electrical faults, surges, or ground potential differences on one port do not affect the others. This is particularly important in distributed industrial systems where devices may be located far apart or powered from different sources.

- RS422/RS485 Configuration:
DIP switches allow users to select between RS422 (full-duplex) and RS485 (half-duplex) operation modes. The Auto-Data-Direction-Control feature simplifies RS485 communication by automatically managing transmit/receive switching.

Typical Use Cases:
- Industrial automation and control systems
- Data acquisition and monitoring networks
- Building management systems (BMS)
- Energy metering and utility monitoring (e.g., flow meters, watt meters, gas recorders)
- SCADA and telemetry systems
- Multi-segment RS485 network expansion

Compatibility:
The S434io is compatible with standard RS422 and RS485 devices, including PLCs, HMIs, sensors, and industrial controllers. It can be integrated into existing serial communication infrastructures without requiring software modification.

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### 5. Components & Accessories

Included Components:
- S434io Serial Port Sharer unit
- UP110 (US type) or UP220 (EU type) power adapter (100–240 VAC input, 5 VDC 1000 mA output)
- User manual and configuration guide
- Packaging with product labeling and serial number

Optional Accessories:
- Mounting brackets or DIN-rail adapters for industrial installation
- RS422/RS485 communication cables (DB9 male to terminal block or DB9 male to DB9 female)
- Additional power adapters for regional standards
- Protective enclosures for harsh environments

Connectors:
- Four DB9 male connectors (Ports A–D)
- Each connector provides five signal pins: TX+, TX–, RX+, RX–, and isolated GND
- DIP switch for RS422/RS485 mode selection

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### 6. Installation & Setup

Requirements:
- Power supply: 5 VDC, 1000 mA (provided via included adapter)
- Compatible RS422/RS485 devices with DB9 or terminal block interfaces
- Proper grounding and isolation practices for industrial environments

Installation Steps:
1. Mounting:
Place the S434io on a stable surface or mount it using optional brackets. Ensure adequate ventilation and avoid exposure to excessive heat or moisture.

2. Power Connection:
Connect the UP110/UP220 adapter to an AC power source (100–240 VAC). Plug the 5 VDC output into the S434io power input jack.

3. Interface Configuration:
Use the internal DIP switch to select RS422 or RS485 mode for each port as required by the connected devices.

4. Wiring:
Connect the master device to Port A and slave devices to Ports B, C, and D using appropriate DB9 cables. Ensure correct polarity for TX+/TX– and RX+/RX– lines.

5. Verification:
Power on the unit. The PWR LED should illuminate. During communication, the ATRX, BTRX, CTRX, and DTRX LEDs will flash to indicate data activity.

6. Testing:
Perform a loopback or communication test to verify proper data transmission between the master and slave devices.

Configuration Notes:
- In RS485 mode, TX+ and RX+ are shorted as DATA+, and TX– and RX– as DATA–.
- Ensure that only one master device is connected to Port A to prevent bus contention.
- Termination resistors may be required for long cable runs or high-speed communication.

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### 7. Performance & Capabilities

Data Transmission:
- Supports standard RS422/RS485 data rates (typically up to 115.2 kbps or higher depending on cable length and environment).
- Auto-direction control ensures efficient half-duplex communication in RS485 mode.

Capacity:
- One master port can communicate with three isolated slave ports.
- Each RS485 segment can support up to 32 devices, allowing a single S434io to manage up to 96 devices (3 × 32) in a multi-drop configuration.

Efficiency:
- Low power consumption (400 mA @ 5 VDC) ensures minimal energy usage.
- Compact design reduces space requirements in control panels or communication racks.

Limitations:
- Designed for one master device only; multiple masters are not supported.
- Cable length and baud rate must be balanced according to RS422/RS485 standards to maintain signal integrity.
- Not intended for use in hazardous or explosive environments without additional protection.

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### 8. Standards & Compliance

Electrical and Safety Standards:
- Complies with RS422 and RS485 electrical interface standards (TIA/EIA-422-B, TIA/EIA-485-A).
- Designed for industrial-grade isolation and signal integrity.

Environmental Compliance:
- Operating and storage conditions meet industrial environmental standards for temperature and humidity.
- RoHS-compliant materials used in manufacturing (lead-free soldering and components).

Certifications:
- CE and FCC compliance (typical for Rayon S400 series products).
- Conforms to international safety and EMC requirements for industrial communication equipment.

Industry Standards Supported:
- RS422 (Full Duplex Differential Signaling)
- RS485 (Half Duplex Differential Signaling with Auto Direction Control)
- DB9 connector pinout standard for serial communication

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### 9. Additional Information

Warranty:
Standard manufacturer warranty (typically one year) covering defects in materials and workmanship under normal operating conditions.

Technical Support:
Rayon Technology provides technical assistance via email and phone. Support includes configuration guidance, troubleshooting, and application consultation.

Maintenance:
- Periodically inspect connectors and cables for wear or corrosion.
- Ensure proper grounding and isolation are maintained.
- Clean the enclosure with a dry cloth; avoid solvents or liquids.

Firmware/Hardware Updates:
The S434io is a hardware-based device with no firmware updates required. Hardware revisions may be released periodically to improve performance or compatibility.

Related Models in the S400 Series:
- S232: RS232 master to 3 RS232 slaves
- S232o: RS232 master to 3 isolated RS232 slaves
- S232io: Isolated RS232 master to 3 isolated RS232 slaves
- S432i: Isolated RS422/485 master to 3 RS232 slaves
- S432io: Isolated RS422/485 master to 3 isolated RS232 slaves
- S234o: RS232 master to 3 isolated RS422/485 slaves
- S234io: Isolated RS232 master to 3 isolated RS422/485 slaves
- S434io: Isolated RS422/485 master to 3 isolated RS422/485 slaves (this model)

Application Example:
In a data collection system, the S434io can be used to connect a central controller (master) to multiple RS485-based meters or sensors. The master sends polling commands to all devices, and only the addressed device responds, ensuring efficient and isolated communication. This architecture simplifies troubleshooting and enhances reliability compared to traditional RS485 bus configurations.

Manufacturer’s Note:
All product names and trademarks mentioned are the property of their respective owners. Rayon Technology reserves the right to modify specifications without prior notice to improve product performance.

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### Summary

The Rayon S434io Serial Port Sharer is a high-performance, isolated communication hub designed for industrial and automation environments requiring robust RS422/RS485 connectivity. It enables one master device to communicate with three isolated slave segments, providing full electrical isolation, flexible configuration, and reliable data transmission. With its compact design, universal power compatibility, and industrial-grade construction, the S434io is ideal for applications such as SCADA systems, energy metering, and distributed control networks where signal integrity and isolation are critical.