Comprehensive Product Summary – Rayon Technology F641N 8-Port RS232 Connector Box

---

### 1. Product Overview

Product Name: F641N RS232 Connector Box
Model: F641N
Series: F641 / F642 Multiport Serial Expansion Series
Article Number: F641N
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)

The Rayon F641N is an 8-port RS232C connector box designed for use with Rayon’s intelligent multiport communication cards such as the P640NU and IOP3927F. It provides high-performance serial connectivity through a FIFO-type 16C554 UART controller, enabling efficient data handling and reduced CPU load. The F641N supports daisy-chaining of up to eight boxes, allowing expansion to 64 serial ports per system.

---

### 2. Key Features

- Eight RS232C Ports per Box: Each F641N unit provides eight independent RS232 serial ports, each with full hardware handshaking and control lines.
- Built-in FIFO UART Controller: Integrated 16C554 FIFO-type UART chip ensures smooth data flow and minimizes CPU overhead by buffering data at the hardware level.
- High-Speed Communication: Supports baud rates from 110 bps up to 230.4 kbps, suitable for a wide range of serial communication applications.
- Expandable Architecture: Up to eight F641N boxes can be daisy-chained to a single IOP3927F or P640NU card, supporting a total of 64 serial ports.
- Flexible Interface Compatibility: Designed for RS232C standard communication; compatible with various Rayon intelligent I/O cards.
- Hardware and Software Flow Control: Supports both RTS/CTS hardware flow control and Xon/Xoff software flow control.
- Industrial-Grade Design: Durable construction with stable operation across a wide environmental range.
- Compact Form Factor: Space-efficient design suitable for rack or desktop integration.
- Optional IRQ Line: Provides optional interrupt request (IRQ) line connection from box to card for optimized performance.
- Daisy-Chain Connectivity: Equipped with DB37 female (input) and DB37 male (output) connectors for chaining multiple boxes.

---

### 3. Technical Specifications

Interface Type: RS232C (EIA/TIA-232 standard)
Controller: FIFO-type 16C554 UART
Number of Ports: 8 per box
Connector Type: DB25 male connectors (8 total)
Upstream/Downstream Connectors:
- DB37 female (input from card)
- DB37 male (output to next box)

Pin Assignments (DB25):
- Pin 1 – Frame Ground
- Pin 2 – Transmit Data (TXD) Out
- Pin 3 – Receive Data (RXD) In
- Pin 4 – Request to Send (RTS) Out
- Pin 5 – Clear to Send (CTS) In
- Pin 6 – Data Set Ready (DSR) In
- Pin 7 – Signal Ground
- Pin 8 – Data Carrier Detect (DCD) In
- Pin 20 – Data Terminal Ready (DTR) Out

Flow Control: Xon/Xoff or RTS/CTS
Baud Rate Support:
110, 135, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200, 230400 bps
(Note: Software compatibility mapping for high-speed modes: 57600→50, 76800→75, 115200→150, 230400→200 bps)

Dimensions: 231 mm × 89 mm × 38 mm (9.1 × 3.5 × 1.5 inches)
Weight: Approx. 0.8–1.0 kg (typical, depending on configuration)
Material: Metal chassis with anti-interference shielding
Color: Industrial gray finish

Environmental Conditions:
- Operating Temperature: 5°C to 40°C
- Storage Temperature: 0°C to 65°C
- Operating Humidity: 10–90% RH (non-condensing)
- Storage Humidity: 5–90% RH

---

### 4. Functionality

The F641N functions as an external serial port expansion module for Rayon’s intelligent I/O processor cards. It provides eight RS232C ports managed by an onboard 16C554 UART controller, which handles serial data buffering and transmission independently of the host CPU.

Operational Principle:
- The F641N connects to a host card (e.g., P640NU or IOP3927F) via a 37-pin D-type cable.
- The host card communicates with the F641N through a high-speed parallel interface, offloading serial communication tasks from the main CPU.
- Each UART channel in the F641N manages its own transmit and receive buffers, ensuring efficient data flow even under heavy load.
- Multiple F641N units can be daisy-chained, with each additional box expanding the available serial ports by eight.

Typical Use Cases:
- Multi-user terminal systems
- Industrial automation and control
- POS (Point-of-Sale) systems
- Data acquisition and instrumentation
- Communication servers and serial device networking
- Legacy equipment integration requiring multiple RS232 interfaces

Compatibility:
- Fully compatible with Rayon P640NU, P640N, and IOP3927F intelligent multiport cards.
- Supported by operating systems including Windows NT/2000/XP, Linux, and SCO UNIX through dedicated Rayon drivers.
- Can be integrated into PC/AT or compatible systems via PCI interface cards.

---

### 5. Components & Accessories

Included Components:
- F641N 8-Port RS232 Connector Box
- DB37 interconnect cable (optional, depending on kit)
- Mounting brackets (for multi-box installation)
- User manual and driver diskette (for supported OS)

Optional Accessories:
- A640 Cable: Connects P640NU card to F641N box
- Additional F641N Boxes: For daisy-chain expansion (up to 8 total)
- Mounting Brackets: For securing multiple boxes in a rack or base assembly
- IOP3927F Intelligent I/O Processor Card: Required for intelligent multiport operation
- P640NU PCI Card: For standard RS232 expansion applications

Connectors:
- DB25 Male (x8): RS232 serial ports
- DB37 Female: Input from host card
- DB37 Male: Output to next box in chain

---

### 6. Installation & Setup

System Requirements:
- PC/AT or compatible system with available PCI slot
- Compatible Rayon host card (P640NU or IOP3927F)
- Supported operating system (Windows NT/2000/XP, Linux, SCO UNIX)

Installation Steps:
1. Hardware Connection:
- Connect the A640 cable from the host card’s DB37 connector to the DB37 female port on the F641N.
- If multiple boxes are used, connect the DB37 male output of the first box to the DB37 female input of the next.
- Secure boxes using the provided brackets for stability.
2. Power-On Sequence:
- Power on the PC and verify that the F641N’s LED indicators illuminate, confirming communication with the host card.
3. Driver Installation:
- Install the appropriate Rayon driver for your operating system.
- Configure COM port assignments as required.
4. Verification:
- Use terminal software (e.g., HyperTerminal or Rayon’s “etty” utility) to test communication on each port.

Mounting Options:
- Desktop placement for single-box setups.
- Bracket-based mounting for multi-box daisy-chain configurations.
- Rack or panel integration for industrial environments.

Configuration Notes:
- Each F641N box is automatically detected by the host card.
- Box numbering increases sequentially from the card outward (Box 1 nearest the card).
- Ensure correct IRQ assignment if using optional interrupt line.

---

### 7. Performance & Capabilities

Data Throughput: Up to 230.4 kbps per port
Port Capacity: 8 ports per box; up to 64 ports per system (8 boxes)
Controller Efficiency: FIFO buffering minimizes CPU load and prevents data loss at high speeds.
Latency: Low-latency communication due to intelligent UART management.
Scalability: Modular design allows incremental expansion without system redesign.
Reliability: Industrial-grade components ensure stable operation under continuous load.
Limitations:
- RS232 cable length limited to standard specification (~15 meters typical).
- Requires compatible Rayon host card for operation.
- Not designed for RS422/RS485 applications (use F642 for those).

---

### 8. Standards & Compliance

Interface Standards:
- EIA/TIA RS232C compliant
- Compatible with standard DB25 pinout conventions

Electrical & Safety Compliance:
- Designed for PC/AT compatible systems
- Meets general CE and FCC Class A electromagnetic compatibility standards (typical for Rayon products)

Software & Driver Support:
- Windows NT/2000/XP: Plug-and-play driver installation via Rayon-provided INF files
- Linux: Source-level driver installation with kernel integration
- SCO UNIX: Kernel-linked driver installation via custom or tar-based methods

Industry Standards Supported:
- UART 16C554 FIFO architecture
- PCI bus communication via IOP3927F or P640NU interface
- RS232 signal levels per EIA/TIA-232 specification

---

### 9. Additional Information

Warranty:
- One-year limited warranty covering defects in materials and workmanship.
- Excludes damage from misuse, unauthorized servicing, or electrical faults.
- Warranty repairs are free of charge; out-of-warranty repairs available at a flat rate.

Support & Maintenance:
- Technical support available via email (rayon@ms1.hinet.net).
- RMA (Return Material Authorization) required for all returns.
- Users advised to contact Rayon support before returning products to verify if issues are software-related.

Maintenance Recommendations:
- Keep connectors clean and free of dust.
- Avoid exposure to excessive humidity or temperature extremes.
- Periodically check cable connections and bracket mounts for stability.

Firmware & Driver Updates:
- Updated drivers available from Rayon’s website.
- Linux driver source code provided for kernel version compatibility.
- Windows drivers support automatic COM port assignment and configuration.

Repair Procedure:
- Obtain RMA number from Rayon Service Representative.
- Provide model number, serial number, and failure description.
- Return product to designated service address with RMA documentation.

Expansion Example Configurations:
- Single Box Setup: One F641N connected to a P640NU card provides 8 RS232 ports.
- Dual Box Setup: Two F641N boxes daisy-chained provide 16 ports.
- Full Expansion: Eight F641N boxes chained to one IOP3927F card provide 64 ports.
- Mixed Interface Systems: Combine F641 (RS232) and F642 (RS422) boxes for hybrid serial environments.

---

### Summary

The Rayon F641N 8-Port RS232 Connector Box is a robust, scalable, and high-performance serial expansion solution engineered for industrial and multi-user computing environments. Its FIFO-based 16C554 UART controller ensures efficient data handling, while its modular daisy-chain design allows seamless expansion up to 64 ports per system. Compatible with multiple operating systems and intelligent I/O cards, the F641N provides a flexible and reliable interface for RS232 communication in demanding applications.

With its solid construction, broad driver support, and proven reliability, the F641N remains a cornerstone component in Rayon’s multiport communication ecosystem—ideal for system integrators, industrial automation engineers, and IT professionals requiring dependable multi-serial connectivity.