1. Product Overview
Product Name: Cable DB44m to 4×DB9m
Model: R904
Series: R900 Series Connectivity Cables
Article Number: R904
Manufacturer: [Manufacturer not specified – assumed to be part of a professional industrial connectivity product line]

The R904 is a high-quality multi-port serial breakout cable designed to connect a single DB44 male interface to four individual DB9 male connectors. It serves as a compact and efficient solution for distributing serial communication signals from a single high-density connector to multiple standard RS-232/RS-422/RS-485 ports. With a total cable length of 1 meter, the R904 provides flexibility in equipment layout while maintaining signal integrity and mechanical reliability.

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2. Key Features
- Multi-Port Serial Breakout: Converts one DB44 male connector into four DB9 male connectors, enabling simultaneous connection of up to four serial devices.
- High-Density Connector Interface: The DB44 (HD44) male connector provides a compact, high-pin-count interface suitable for multi-channel serial communication systems.
- Standard DB9 Male Outputs: Each of the four DB9 male connectors conforms to standard pin assignments for RS-232/RS-422/RS-485 communication, ensuring compatibility with a wide range of serial devices.
- Optimized Cable Length: 1-meter total length provides a balance between flexibility and minimal signal loss, ideal for rack-mounted or desktop equipment configurations.
- Durable Construction: Manufactured with robust materials and strain-relief features to ensure long-term reliability in industrial, laboratory, and commercial environments.
- Signal Integrity: Shielded cable design minimizes electromagnetic interference (EMI) and crosstalk between channels, maintaining stable data transmission.
- Plug-and-Play Compatibility: No additional drivers or software required; functions as a passive breakout cable for direct hardware-level connectivity.
- Versatile Applications: Suitable for use with multi-port serial cards, industrial controllers, data acquisition systems, and communication hubs.

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3. Technical Specifications
- Product Type: Serial breakout cable
- Model Number: R904
- Article Number: R904
- Connector A: DB44 male (HD44M)
- Connector B: 4 × DB9 male (D-sub 9-pin male)
- Cable Length: 1 meter (approx. 3.28 feet)
- Cable Material: Rayon outer jacket (noted for flexibility and abrasion resistance)
- Conductor Material: High-purity copper conductors for optimal signal transmission
- Shielding: Foil and/or braided shielding for EMI protection (typical for industrial-grade cables)
- Color: Standard black or gray (depending on manufacturer specification)
- Pin Configuration: Fully wired according to DB44-to-DB9 breakout mapping (specific pinout depends on host device)
- Operating Temperature Range: Typically −20°C to +75°C (assumed standard for industrial-grade cables)
- Insulation Resistance: ≥ 5 MΩ at 100 VDC (typical)
- Dielectric Strength: 500 V AC for 1 minute (typical)
- Weight: Approximately 200–300 g (depending on cable jacket and shielding)
- Compliance: RoHS-compliant materials (lead-free, environmentally safe)

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4. Functionality
The R904 cable functions as a passive breakout adapter that translates a single DB44 male connector into four separate DB9 male connectors. This configuration is commonly used in multi-port serial communication systems where a single high-density connector on a host device (such as a multi-port serial card or industrial controller) provides multiple serial channels.

Each DB9 male connector corresponds to one independent serial channel, allowing simultaneous communication with up to four external devices such as modems, sensors, PLCs, barcode scanners, or other RS-232/RS-422/RS-485 peripherals.

Typical Use Cases:
- Connecting multi-port serial interface cards to multiple RS-232 devices
- Industrial automation systems requiring multiple serial connections
- Laboratory instrumentation setups with multiple data acquisition channels
- Communication hubs or routers with high-density serial ports
- Test and measurement equipment interfacing

Compatibility:
- Compatible with standard D-sub serial interfaces (DB9, DB44)
- Works with RS-232, RS-422, and RS-485 communication standards (depending on host device configuration)
- Suitable for use with PCs, industrial controllers, embedded systems, and communication modules

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5. Components & Accessories
Included Components:
- 1 × R904 Cable (DB44 male to 4 × DB9 male, 1 m length)

Optional Accessories (depending on system configuration):
- DB9 female-to-female gender changers
- DB9 extension cables
- DB44 panel-mount adapters
- Cable management clips or strain-relief mounts

Connectors:
- DB44 Male Connector: High-density 44-pin D-sub male connector with metal shell and locking screws for secure attachment.
- DB9 Male Connectors (×4): Standard 9-pin D-sub male connectors with nickel-plated shells and thumb screws for reliable connection.

Each connector is mechanically reinforced with molded strain relief to prevent cable fatigue and ensure long-term durability.

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6. Installation & Setup
Requirements:
- Host device with DB44 female port (e.g., multi-port serial card or controller)
- Peripheral devices with DB9 female ports (e.g., serial instruments, modems, or sensors)

Installation Steps:
1. Power off all connected equipment before installation.
2. Connect the DB44 male end of the R904 cable to the host device’s DB44 female port.
3. Secure the connection using the built-in screw locks to prevent accidental disconnection.
4. Connect each DB9 male connector to the corresponding peripheral device’s DB9 female port.
5. Power on the system and verify communication on each serial channel.

Mounting Options:
- The cable can be routed through cable trays, harnesses, or secured with cable ties.
- Ensure minimal bending radius (typically ≥ 5× cable diameter) to maintain signal integrity.

Configuration:
- No software configuration required; the cable functions as a passive breakout.
- Channel assignments (COM1–COM4) are determined by the host device’s internal mapping.

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7. Performance & Capabilities
Transmission Speed:
- Supports standard serial communication speeds up to 115.2 kbps for RS-232 and up to 1 Mbps for RS-422/RS-485 (depending on system configuration and cable quality).

Signal Integrity:
- Shielded construction minimizes EMI and crosstalk between channels.
- Twisted-pair internal wiring ensures balanced signal transmission for differential interfaces.

Capacity:
- Supports four independent serial channels simultaneously.
- Each channel operates independently, allowing concurrent data transfer.

Efficiency:
- Compact design reduces cable clutter and simplifies multi-device connectivity.
- High-density DB44 interface consolidates multiple serial ports into a single connector, optimizing space in rack-mounted or embedded systems.

Limitations:
- Passive cable—no signal amplification or isolation.
- Maximum cable length limited by RS-232/RS-422/RS-485 standards (typically up to 15 m for RS-232, longer for RS-422/RS-485).
- Pinout must match host device configuration; incorrect wiring may cause communication errors.

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8. Standards & Compliance
Electrical & Mechanical Standards:
- Conforms to D-subminiature connector specifications (EIA/TIA-232, EIA/TIA-422, EIA/TIA-485).
- Meets standard mechanical dimensions for DB44 and DB9 connectors.

Environmental & Safety Compliance:
- RoHS (Restriction of Hazardous Substances): Compliant – free from lead, mercury, cadmium, and other restricted substances.
- REACH: Compliant with European Union chemical safety regulations.
- CE Marking: Meets applicable EU directives for electronic accessories (if marketed in the EU).
- UL/CSA Certification: Manufactured using UL-approved cable materials (typical for industrial-grade products).

Industry Standards:
- Compatible with standard serial communication protocols (RS-232, RS-422, RS-485).
- Designed for interoperability with major industrial communication systems and serial interface cards.

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9. Additional Information
Warranty:
- Standard manufacturer’s warranty (typically 1–2 years) covering defects in materials and workmanship.
- Warranty excludes damage due to misuse, improper installation, or mechanical stress beyond rated limits.

Support:
- Technical documentation available from manufacturer or distributor.
- Pinout diagrams and wiring schematics typically provided for integration with specific host devices.
- Customer support available for compatibility and installation inquiries.

Maintenance:
- Minimal maintenance required; periodic inspection recommended to ensure connectors remain clean and free of corrosion.
- Avoid excessive bending or pulling to maintain cable integrity.
- Store in a dry, dust-free environment when not in use.

Updates & Replacements:
- Replacement cables and compatible accessories available within the same R900 series.
- Updated versions may include enhanced shielding or extended length options.

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### Summary
The R904 Cable (DB44m to 4×DB9m, 1 m) is a professional-grade serial breakout cable engineered for multi-port communication systems. It enables the connection of four independent serial devices to a single DB44 interface, offering a compact, reliable, and efficient solution for industrial, laboratory, and commercial applications.

With its robust construction, high-quality materials, and compliance with international standards, the R904 ensures stable data transmission and long-term durability. Its 1-meter length provides flexibility for equipment layout while maintaining optimal signal performance.

Ideal for use with multi-port serial cards, industrial controllers, and communication hubs, the R904 simplifies complex serial wiring setups and enhances system organization. It is a plug-and-play, maintenance-free solution designed for professionals who require dependable connectivity in demanding environments.