1. Product Overview

Product Name: PCIe Isolated 4-Port RS422/485 Card
Model: A134-I (also referenced as A134I)
Series: APCIe Advanced PCIe Serial Communication Card Series
Article Number: A134-I
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)

The Rayon A134-I is a high-performance, industrial-grade PCI Express (PCIe) serial communication card designed to provide four isolated RS422/RS485 ports. Each port can be independently configured via DIP switches, offering flexible deployment in industrial automation, data acquisition, and control systems. The card integrates the Moschip MCS9904 controller, ensuring reliable, high-speed serial communication with full ground isolation for enhanced electrical protection and noise immunity.

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2. Key Features

- Four Independent Serial Ports: Provides four isolated serial communication ports, each configurable as RS422 or RS485.
- Full Ground Isolation: Each port is galvanically isolated to prevent ground loops and protect connected equipment from electrical surges.
- Flexible Configuration: DIP switch selectable interface mode per port (RS422 or RS485).
- Auto Data Direction Control (ADDC): Built-in ADDC feature for RS485 mode enables automatic transmit/receive switching without software control.
- High-Speed Communication: Supports baud rates from 50 bps up to 115,200 bps per port.
- Plug & Play PCIe Interface: Fully compliant with PCI Express bus architecture; I/O, memory, and IRQ resources are automatically assigned by the PCI BIOS.
- Industrial-Grade Design: Rugged construction and wide environmental tolerance make it suitable for industrial control and automation systems.
- Comprehensive OS Support: Compatible with Windows 2000, XP, Vista, Windows 7, and Linux operating systems.
- Compact Form Factor: Standard PCIe bracket with dimensions of 120 mm × 105 mm.
- Included Connectivity Cable: Ships with a DB37 male to 4×DB9 male expansion cable for easy connection to external devices.
- Optional Accessories: DB37 to 4×DB25 male cable (A400) available for alternative connector configurations.
- Enhanced System Performance: 128-byte transmit and receive FIFO buffers per port reduce CPU interrupt load, improving multitasking efficiency.
- Industrial Reliability: Designed for continuous operation in environments with high electrical noise and variable temperature/humidity conditions.

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3. Technical Specifications

Controller Chip: Moschip MCS9904 (PCIe to multi-port serial controller)
Bus Interface: PCI Express (PCIe) x1 slot, compliant with PCIe specification
Number of Ports: 4 isolated serial ports
Interface Standards: RS422 / RS485 (selectable per port)
Isolation: Ground isolation per port
Baud Rate: 50 bps to 115,200 bps (software programmable)
Flow Control: Supports XON/XOFF (software) and RTS/CTS (hardware) flow control
FIFO Buffer: 128 bytes transmit and 128 bytes receive per port
Connector Type: DB37 female connector on card
Expansion Cable:
- Standard included: DB37 male to 4×DB9 male (P485 cable)
- Optional: DB37 male to 4×DB25 male (A400 cable)

Dimensions: 120 mm (L) × 105 mm (W)
Bracket Type: Standard PCIe bracket
Weight: Approx. 150 g (card only, without cable)
Material: Multi-layer PCB with EMI shielding and industrial-grade components

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)

Electrical Characteristics:
- Isolation Voltage: Typically 1,500 VDC between ports and system ground
- Power Source: Supplied via PCIe bus (no external power required)

System Resource Allocation:
- I/O Mapping: Assigned by PCI BIOS
- Memory Mapping: Assigned by PCI BIOS
- IRQ Mapping: Four IRQs assigned by PCI BIOS

Compliance: Fully Plug & Play compatible with PCI BIOS resource management

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4. Functionality

The A134-I operates as a four-port serial communication interface card for PCIe-based systems. Each port can be configured independently as RS422 or RS485 using onboard DIP switches:

- RS422 Mode: Supports full-duplex differential signaling for point-to-point or multi-drop communication.
- RS485 Mode: Supports half-duplex differential signaling for multi-drop networks, with automatic data direction control (ADDC) to eliminate the need for manual RTS control.

Use Cases and Applications:
- Industrial automation and process control
- SCADA systems and PLC communication
- Data acquisition and monitoring systems
- Serial device networking and remote I/O control
- Machine-to-machine (M2M) communication
- Industrial instrumentation and test equipment interfaces

Compatibility:
- Compatible with standard PCIe slots on desktop PCs, industrial PCs, and embedded systems.
- Supports major operating systems: Windows 2000, XP, Vista, Windows 7, and Linux distributions (RedHat, SUSE, Slackware).
- Linux driver package supports kernel versions up to 2.6.x and allows up to four cards per system.

Device Naming (Linux):
- 4-port card device nodes: `/dev/tty2[1–4][a–d]` (e.g., `/dev/tty21a` to `/dev/tty21d`)

Driver Integration:
- Windows: Uses Moschip MCS9904 driver package.
- Linux: Installed via Rayon-provided driver scripts (`Install.redhat`), configurable for kernel version and card type.

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5. Components & Accessories

Included Components:
- 1 × A134-I PCIe interface card
- 1 × DB37 male to 4×DB9 male expansion cable (P485)
- 1 × User manual and driver CD (Windows and Linux drivers)

Optional Accessories:
- A400 cable: DB37 male to 4×DB25 male connectors
- RS4232-4 or RS4232-8 isolated converter boxes for extended isolation and signal conversion
- TB485 terminal block adapter for RS485 wiring (DATA+, DATA–, GND)
- RS232/RS422/RS485 loopback connectors for testing

Connectors and Pinouts:
- DB37 female connector on card (see Appendix A-2 for pin assignments)
- DB9 male connectors on expansion cable (see Appendix A-4 for RS422/RS485 signal mapping)

Signal Mapping (DB9 RS422/RS485):
- Pin 2: RXD+ (Input)
- Pin 3: TXD+ (Output)
- Pin 4: TXD– (Output)
- Pin 5: Isolated GND
- Pin 6: RXD– (Input)

Isolation: Each port provides isolated ground reference to prevent cross-interference between channels.

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6. Installation & Setup

System Requirements:
- Available PCI Express slot (x1 or higher)
- Supported operating system (Windows 2000/XP/Vista/7 or Linux)
- Administrator privileges for driver installation

Installation Procedure:
1. Power off the host system.
2. Insert the A134-I card into an available PCIe slot.
3. Secure the card with the bracket screw.
4. Connect the DB37 expansion cable to the card’s connector.
5. Attach serial devices to the DB9 connectors on the cable.
6. Power on the system.
7. Install the appropriate driver software.

Driver Installation (Windows):
- The system’s Plug & Play function detects the new hardware.
- Specify the driver path (e.g., `D:\PCIe_Card\APCIe\WIN32\StnMf.inf`).
- Install the Moschip MCS9904 driver.
- Verify installation under Device Manager:
- “PCIe to Multifunction Peripheral Controller” (card driver)
- “PCIe to High Speed Serial Port” (individual COM ports)

Driver Installation (Linux):
- Copy driver package to `/etc/rayone`.
- Run installation script (`./Install.redhat`).
- Select card type (APCIe/MPe9900), kernel version, and rebuild system.
- Reboot to activate new serial devices.

DIP Switch Configuration:
- 4-bit DIP switch (SW1) controls port interface type:
- Bit 1: Port A (ON = RS422, OFF = RS485)
- Bit 2: Port B (ON = RS422, OFF = RS485)
- Bit 3: Port C (ON = RS422, OFF = RS485)
- Bit 4: Port D (ON = RS422, OFF = RS485)

Cabling Notes:
- For RS485 mode, short DB9 pins 2 & 3 (DATA+) and pins 4 & 6 (DATA–).
- Use twisted-pair shielded cable for long-distance communication.
- Ensure proper termination (120 Ω resistors) at both ends of RS485 bus.

Safety Note:
Do not insert or remove the card while the system is powered on.

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7. Performance & Capabilities

Data Throughput:
- Up to 115.2 kbps per port (standard)
- Supports full-duplex (RS422) and half-duplex (RS485) communication

Buffering:
- 128-byte transmit and receive FIFO per port minimizes CPU load and prevents data loss during high-speed transfers.

Interrupt Handling:
- PCI BIOS assigns IRQs automatically; supports IRQ sharing with other PCIe devices.

Efficiency:
- Reduced CPU interrupt frequency due to large FIFO buffers.
- Optimized for multitasking environments and real-time control applications.

Limitations:
- RS485 mode supports half-duplex only (one transmitter active at a time).
- Maximum cable length depends on baud rate and cable quality (typically up to 1200 m at 9600 bps).
- No RI (Ring Indicator) signal support on isolated cards.

Reliability:
- Designed for continuous 24/7 operation in industrial environments.
- Ground isolation prevents communication errors due to potential differences.

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8. Standards & Compliance

Bus Interface Standard: PCI Express (PCIe)
Serial Communication Standards: EIA/TIA RS422 and RS485 compliant
Isolation Standard: Industrial-grade galvanic isolation
Plug & Play Compliance: Fully compliant with PCI BIOS resource allocation
Operating System Compatibility:
- Windows 2000 / XP / 2003 / Vista / 7
- Linux (kernel 2.6.x and later)
Hardware Identification:
- Vendor ID: 9710 (Moschip)
- Device ID: 9904 (4-port configuration)

Industry Certifications:
- CE and FCC Class A (industrial environment)
- RoHS compliant (lead-free manufacturing)

Regulatory Compliance:
- Meets EMI/EMC standards for industrial computing equipment
- Designed in accordance with ISO9001 quality management standards

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9. Additional Information

Warranty:
- One-year limited hardware warranty covering defects in materials and workmanship.
- Warranty excludes damage from misuse, electrical surges, or unauthorized servicing.

Repair & RMA Procedure:
- Contact Rayon Technology for Return Material Authorization (RMA).
- Provide model number, serial number, and problem description.
- Products under warranty repaired at no cost; out-of-warranty repairs subject to flat-rate service charge.

Technical Support:
- Email: rayon@ms1.hinet.net
- Support includes driver updates, installation assistance, and troubleshooting.

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

Software Updates:
- Updated drivers and manuals available from Rayon’s website.
- Linux driver source code provided for kernel recompilation and customization.

Related Products in the APCIe Series:
- A102: 2-port RS232 PCIe card
- A132: 2-port RS422/RS485 PCIe card
- A112: 2-port RS232/RS422/RS485 PCIe card
- A104: 4-port RS232 PCIe card
- A114: 4-port RS232/RS422/RS485 PCIe card
- A168: 8-port RS232 PCIe card
- A138: 8-port RS422/RS485 PCIe card
- A118: 8-port RS232/RS422/RS485 PCIe card
- A124I: 2-port RS232 + 2-port isolated RS422/RS485 PCIe card

Summary:
The Rayon A134-I PCIe Isolated 4-Port RS422/485 Card is a robust, flexible, and high-performance communication interface designed for industrial and embedded applications requiring reliable serial connectivity. Its combination of ground isolation, configurable interfaces, and broad OS support makes it an ideal solution for engineers integrating serial devices into modern PCIe-based systems. The card’s plug-and-play architecture, comprehensive driver support, and industrial-grade design ensure long-term stability and ease of deployment in demanding environments.