Comprehensive Product Summary – Rayon Technology RJ422 PCI 2-Port RS422 RJ45 Card

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### 1. Product Overview

Product Name: RJ422 PCI 2-Port RS422 RJ45 Card
Model Number: RJ422
Series: RAYON PCIPORT Series
Article Number: RJ422
Manufacturer: Rayon Technology Inc.
Manufacturer Tagline: *Engineered to Connect*
Revision: Manual Rev. 1.00 (October 19, 2003)
Manufacturer Locations:
- Taiwan Headquarters: Rayon Technology Co. Ltd., 2F, No. 177, Chung-Shan 2 Road, Lu-Chou City, Taipei Hsien, Taiwan R.O.C.
- European Support: Acceed GmbH, Arnoldstraße 19, 40479 Düsseldorf, Germany

The RJ422 is a PCI-based intelligent serial communication card designed to provide two high-performance RS422 ports via RJ45 connectors. It belongs to Rayon’s PCIPORT family of multi-port serial interface cards, engineered for industrial, automation, and communication applications requiring reliable, high-speed, differential serial data transmission.

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### 2. Key Features

- Dual RS422 Ports: Provides two independent RS422 serial communication channels via RJ45 connectors.
- PCI Plug & Play Interface: Fully compliant with PCI Local Bus Specification Rev. 2.1, supporting automatic resource assignment (I/O address, IRQ) by system BIOS.
- High-Speed Data Transmission: Supports baud rates up to 115.2 Kbps (standard 1.8432 MHz crystal) or up to 921.6 Kbps with optional 14.7456 MHz crystal.
- 16C550A-Compatible UARTs: Each port includes a 16-byte transmit and receive FIFO buffer, reducing CPU interrupt load and improving system throughput.
- Hardware and Software Flow Control: Supports both RTS/CTS and XON/XOFF flow control mechanisms.
- Industrial-Grade RS422 Interface: Differential signaling for noise immunity and long-distance communication.
- RJ45 Connector Interface: Compact and modular connector design for easy cabling and integration.
- Jumper-Selectable Termination: Each port includes a jumper to enable or disable 120 Ω termination resistors for proper line impedance matching.
- Multi-OS Driver Support: Compatible with Windows 95/98/Me, Windows NT, Windows 2000/XP, DOS, Linux, and SCO OpenServer.
- IRQ Sharing Capability: Supports shared interrupt operation for multiple PCI cards in the same system.
- Universal PCI Voltage Support: Operates in both 5V and 3.3V PCI slots (universal PCI design).
- Compact and Reliable Design: Built with high-quality components for industrial and embedded system environments.

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### 3. Technical Specifications

Bus Interface:
- PCI Local Bus Specification Rev. 2.1 compliant
- 32-bit, 33 MHz PCI bus
- Universal PCI (3.3V and 5V signaling)

Serial Controller:
- 16C550A-compatible UART
- 16-byte transmit and receive FIFO
- Clock frequency: 1.8432 MHz (standard), optional 14.7456 MHz

Communication Interface:
- RS422 differential signaling
- Full-duplex operation
- Balanced transmission lines for noise immunity
- Jumper-selectable termination resistors per port

Connectors:
- Two RJ45 female connectors
- Pin assignments per port:
1. TXD+ (Transmit Data +)
2. RXD+ (Receive Data +)
3. RTS (Request to Send)
4. CTS (Clear to Send)
5. DSR / RXD– (Receive Data –)
6. GND
7. DTR / TXD– (Transmit Data –)
8. DCD (Data Carrier Detect)

Baud Rate:
- Up to 115.2 Kbps (1.8432 MHz crystal)
- Up to 921.6 Kbps (14.7456 MHz crystal)

Flow Control:
- Hardware: RTS/CTS
- Software: XON/XOFF

Interrupt Control:
- Assigned automatically by PCI BIOS
- Supports IRQ sharing

Operating Environment:
- Compatible with PC/AT systems
- Operating voltage: 5V or 3.3V PCI slot
- Operating temperature: 0°C to 55°C (typical)
- Storage temperature: –20°C to 85°C
- Relative humidity: 5%–95% non-condensing

Physical Characteristics:
- Form Factor: Standard PCI short card
- Dimensions: Approx. 120 mm (L) × 65 mm (H)
- Weight: Approx. 100 g
- Material: Multi-layer PCB with gold-plated edge connector

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### 4. Functionality

Operation Principle:
The RJ422 card provides two independent RS422 serial communication channels through the PCI bus. Each port uses a 16C550A-compatible UART with FIFO buffering to minimize CPU interrupts. The card’s ASIC-based PCI controller automatically handles bus configuration, eliminating manual resource setup.

Use Cases and Applications:
- Industrial automation and control systems
- Data acquisition and instrumentation
- Building management systems (BMS)
- SCADA and PLC communication
- Serial device networking (sensors, controllers, modems)
- Long-distance serial communication (up to 1200 meters typical for RS422)
- Embedded systems requiring reliable differential signaling

Compatibility:
- Fully compatible with standard RS422 devices and cabling
- Supports RJ45-to-terminal block or RJ45-to-DB9/DB25 adapters
- Compatible with other Rayon PCIPORT series accessories

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### 5. Components & Accessories

Included Items:
- RJ422 PCI 2-Port RS422 RJ45 Card
- User Manual
- Driver Diskette (DOS, Windows, Linux, SCO)

Optional Accessories:
- RJ45-to-DB9 or RJ45-to-DB25 adapter cables
- TB485 converter (DB9 to 3-pin terminal block for RS485 applications)
- RS4232-4 or RS4232-8 isolation boxes (for galvanic isolation and RS232/RS422/RS485 conversion)
- Shielded twisted-pair cables for long-distance RS422 communication

Connectors and Cabling:
- RJ45 connectors with standard pinout for RS422 differential pairs
- Jumper-selectable termination resistors per port
- Optional external termination or biasing resistors for network tuning

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### 6. Installation & Setup

System Requirements:
- Available PCI slot (32-bit, 33 MHz)
- PC/AT compatible system
- Supported operating system (Windows, DOS, Linux, SCO)

Installation Procedure:
1. Power off the computer and unplug it.
2. Insert the RJ422 card into an available PCI slot.
3. Secure the card with the bracket screw.
4. Connect RJ45 cables to the desired RS422 devices.
5. Power on the system.
6. Install the appropriate driver for your operating system.

Driver Installation:
- Windows 2000/XP: Automatic Plug & Play detection; specify driver path (A:\WIN2000).
- Windows NT4: Manual installation via *Control Panel → Network → Add Adapter → Other → A:\P220\NT4*.
- Windows 95/98/Me: Plug & Play detection; specify driver path (A:\WIN95).
- DOS: Copy driver files from diskette and run `PCIPORT` or `P984` installer.
- Linux: Extract driver source (`tar xvf /dev/fd0`), run `./Install`, rebuild kernel modules, and reboot.
- SCO OpenServer: Install via `/etc/custom` or manual `tar` and `build` commands.

Configuration:
- Jumper JP1: Selects card number (ON = first card, OFF = second card).
- Per-Port Termination Jumpers: Enable/disable 120 Ω termination resistors.
- DIP Switches (if applicable): Configure RS422/RS485 mode (default RS422).

Caution:
- Do not insert or remove the card while the system is powered on.
- Use anti-static precautions during installation.

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### 7. Performance & Capabilities

Data Throughput:
- High-speed serial communication up to 921.6 Kbps (with optional crystal).
- 16-byte FIFO buffers per port reduce CPU load and improve multitasking performance.

Capacity:
- Two independent RS422 channels per card.
- Up to four RJ422 cards can be installed in one system (total 8 ports).

Efficiency:
- ASIC-based PCI controller minimizes CPU interrupts.
- Supports shared IRQ operation for multiple cards.

Limitations:
- No galvanic isolation (use P422I or RS4232 box for isolation).
- RS422 only (no RS485 mode on this model).
- Requires proper grounding between connected devices to prevent common-mode voltage issues.

Reliability:
- Designed for continuous industrial operation.
- Stable performance under high EMI environments due to differential signaling.

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### 8. Standards & Compliance

Electrical and Interface Standards:
- PCI Local Bus Specification Rev. 2.1
- EIA/TIA RS422 Standard for balanced differential signaling
- 16C550A UART compatibility

Software and OS Compatibility:
- Microsoft Windows 95/98/Me/NT/2000/XP
- DOS
- Linux (kernel 2.4.x and later, source-based driver installation)
- SCO OpenServer

Regulatory Compliance:
- CE and FCC Class A (industrial environment)
- RoHS-compliant materials (for later production batches)

Industry Standards:
- Compatible with standard RJ45 pinout for RS422
- Supports standard serial communication protocols (Modbus RTU, ASCII, etc.)

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### 9. Additional Information

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

Repair & RMA Procedure:
- Obtain Return Material Authorization (RMA) number before returning products.
- Provide model number, serial number, purchase order, and problem description.
- Contact:
- Taiwan: rayon@ms1.hinet.net
- Europe: rayon@acceed.com

Support & Maintenance:
- Technical support via email (Taiwan and Europe).
- Driver updates and documentation available from Rayon or Acceed websites.
- Preventive maintenance: ensure proper grounding and cable shielding.

Software Updates:
- Updated drivers available for newer operating systems.
- Source code provided for Linux driver customization.

Troubleshooting Highlights:
- If card not detected, verify PCI slot and BIOS resource assignment.
- If communication fails, check termination jumpers and cable polarity.
- Use “RAYONTTY.EXE” terminal utility for port testing under DOS.
- For IRQ conflicts, relocate card or adjust BIOS settings.

Recommended Practices:
- Use twisted-pair shielded cables for RS422 connections.
- Disable unused terminators on idle ports to prevent signal reflection.
- Maintain consistent ground potential across connected devices.

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### Summary

The Rayon RJ422 PCI 2-Port RS422 RJ45 Card is a robust, high-performance serial communication interface designed for industrial and embedded applications requiring reliable differential signaling. With its dual RS422 ports, PCI Plug & Play architecture, and comprehensive driver support across multiple operating systems, the RJ422 provides a flexible and efficient solution for expanding serial connectivity in PC-based systems. Its jumper-configurable termination, hardware flow control, and universal PCI compatibility make it suitable for a wide range of automation, instrumentation, and data communication environments.

The RJ422 exemplifies Rayon Technology’s commitment to connectivity and reliability, offering a cost-effective, technically advanced interface card for professional and industrial users.