1. Product Overview
Product Name: Cable DB37f to 4×DB25m
Model: A401
Series: RS Interface Cable Series
Article Number: A401
Manufacturer: Rayon

The Rayon A401 is a specialized interface cable designed to connect a single DB37 female connector to four DB25 male connectors. With a total cable length of 0.2 meters, this product is engineered for compact installations and short-distance signal routing. It is primarily intended for use with the Rayon RS4232-4 communication interface box, providing a reliable and organized method of distributing serial communication lines from a single multi-channel connector to multiple standard DB25 ports.

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2. Key Features
- Multi-Port Connectivity: Converts one DB37 female interface into four DB25 male outputs, enabling simultaneous connection of up to four serial devices.
- Optimized for RS4232-4 Systems: Specifically designed for compatibility with the Rayon RS4232-4 box, ensuring seamless integration and signal integrity.
- Compact Design: With a total length of 0.2 meters, the cable minimizes clutter and signal loss in confined installation environments.
- High-Quality Construction: Manufactured with precision-molded connectors and shielded cabling to maintain signal quality and reduce electromagnetic interference (EMI).
- Durable Connectors: The DB37 female and DB25 male connectors are equipped with metal shells and strain reliefs for mechanical stability and long service life.
- Plug-and-Play Operation: No additional configuration or software setup required; simply connect to the RS4232-4 box and compatible devices.
- Versatile Application: Suitable for industrial automation, data acquisition systems, serial communication hubs, and legacy equipment interfacing.

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3. Technical Specifications
- Product Type: Interface Cable / Adapter Cable
- Model Number: A401
- Article Number: A401
- Manufacturer: Rayon
- Connector Type 1: DB37 Female (37-pin D-subminiature connector)
- Connector Type 2: 4 × DB25 Male (25-pin D-subminiature connectors)
- Cable Length: 0.2 meters (20 centimeters)
- Cable Type: Shielded multi-core cable for serial data transmission
- Pin Configuration: One-to-four breakout mapping from DB37 to DB25 connectors (specific pin assignments correspond to RS4232-4 interface design)
- Material Composition:
- Cable Jacket: PVC or equivalent flexible insulation
- Conductor Material: Tinned copper conductors for optimal conductivity
- Connector Shells: Nickel-plated metal for EMI protection
- Contact Material: Gold-plated or tin-plated contacts for corrosion resistance
- Color: Standard black or gray (depending on production batch)
- Operating Temperature Range: -20°C to +70°C (typical for industrial-grade cables)
- Storage Temperature Range: -40°C to +85°C
- Weight: Approximately 150–200 grams (depending on connector housing)
- Shielding: Full foil and braid shielding for noise suppression
- Insulation Resistance: ≥ 100 MΩ at 500 VDC
- Dielectric Strength: 1000 VAC for 1 minute between conductors and shield
- Bend Radius: Minimum 10× cable diameter for safe installation

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4. Functionality
The Rayon A401 cable functions as a breakout adapter, converting a single DB37 female interface into four separate DB25 male interfaces. This configuration is particularly useful in multi-channel serial communication systems where multiple RS-232 or RS-423 devices need to be connected to a single controller or interface module.

How It Works:
- The DB37 female connector attaches to the corresponding DB37 male port on the RS4232-4 box.
- Internally, the cable routes specific signal lines from the DB37 connector to each of the four DB25 male connectors, effectively distributing the communication channels.
- Each DB25 male connector can then be connected to an individual serial device, such as a terminal, modem, or industrial controller.
- The cable ensures proper grounding and shielding continuity to maintain signal integrity across all channels.

Use Cases and Applications:
- Industrial Automation: Connecting multiple serial devices (PLCs, sensors, controllers) to a single communication hub.
- Data Acquisition Systems: Distributing data lines from a central acquisition unit to multiple measurement instruments.
- Laboratory Equipment: Interfacing legacy RS-232 instruments with modern control systems.
- Communication Systems: Expanding serial port availability in multi-channel communication setups.
- Testing and Diagnostics: Providing a convenient breakout for monitoring or testing multiple serial lines simultaneously.

Compatibility:
- Fully compatible with Rayon RS4232-4 interface boxes.
- Suitable for other equipment utilizing DB37-to-DB25 serial breakout configurations, provided pin assignments match.
- Compatible with standard RS-232, RS-423, and RS-422 signal levels depending on connected devices.

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5. Components & Accessories
Included Items:
- 1 × Rayon A401 Cable (DB37 Female to 4 × DB25 Male, 0.2 m length)

Optional Accessories (sold separately):
- DB25 extension cables (various lengths)
- DB25-to-DB9 adapters for connecting to devices with DB9 serial ports
- Mounting brackets or cable management clips for securing the cable assembly
- RS4232-4 interface box (required for primary operation)

Connectors and Interfaces:
- DB37 Female Connector:
- 37-pin D-subminiature type
- Screw-lock mechanism for secure attachment
- Metal shell for EMI shielding
- DB25 Male Connectors (×4):
- 25-pin D-subminiature type
- Screw-lock retention
- Numbered labeling for channel identification (e.g., Port 1–4)

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6. Installation & Setup
Requirements:
- Compatible RS4232-4 box or equivalent DB37 interface port
- Available DB25 female ports on target devices
- Adequate clearance for connector placement (each DB25 connector requires approximately 53 mm width)

Mounting Options:
- Direct plug-in connection to the RS4232-4 box
- Cable can be routed through cable trays or secured with cable ties for strain relief
- Recommended to avoid sharp bends or excessive tension on connectors

Configuration:
- No software or firmware configuration required; purely hardware-level connection
- Ensure correct orientation of connectors before insertion
- Tighten connector screws to prevent accidental disconnection
- Verify pinout compatibility if used with non-Rayon equipment

Installation Steps:
1. Power off all connected devices before installation.
2. Connect the DB37 female end of the A401 cable to the RS4232-4 box.
3. Secure the connection using the built-in screw locks.
4. Connect each DB25 male connector to the corresponding device port.
5. Power on the system and verify communication on all channels.

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7. Performance & Capabilities
Signal Transmission:
- Supports standard asynchronous serial communication protocols (RS-232, RS-423, RS-422).
- Maintains signal integrity over short distances (0.2 m) with minimal attenuation.
- Shielded design minimizes crosstalk between channels.

Speed and Capacity:
- Capable of supporting baud rates up to 115.2 kbps or higher, depending on connected devices and system configuration.
- Four independent communication channels via DB25 connectors.

Efficiency:
- Compact length reduces signal delay and electromagnetic interference.
- Optimized conductor layout ensures balanced impedance and consistent performance.

Limitations:
- Designed for short-distance internal connections; not suitable for long cable runs.
- Pinout is specific to RS4232-4 systems; may require verification for third-party compatibility.
- Not intended for high-voltage or power transmission applications.

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8. Standards & Compliance
Electrical and Mechanical Standards:
- Conforms to D-subminiature connector standards (IEC 60807-3 / MIL-DTL-24308).
- Meets RS-232/RS-423/RS-422 signal interface specifications.
- Manufactured in compliance with RoHS (Restriction of Hazardous Substances) directives.
- REACH compliant for material safety and environmental standards.
- Quality assurance under ISO 9001 manufacturing processes.

Safety and Environmental Compliance:
- Flame-retardant cable jacket meeting UL VW-1 or equivalent rating.
- Halogen-free insulation options available upon request.
- Tested for mechanical durability and electrical continuity.

Industry Standards:
- Compatible with EIA/TIA-232-F and EIA/TIA-423-B communication standards.
- Designed for use in industrial, laboratory, and commercial communication systems.

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9. Additional Information
Warranty:
- Standard manufacturer’s warranty: 12 months from date of purchase (subject to Rayon’s warranty policy).
- Covers defects in materials and workmanship under normal operating conditions.

Support:
- Technical documentation and pinout diagrams available from Rayon’s support portal.
- Customer service and technical assistance provided via email or authorized distributors.

Maintenance:
- Periodic inspection recommended to ensure connector integrity and cable condition.
- Clean connectors with dry, lint-free cloth; avoid exposure to moisture or corrosive environments.
- Replace cable if visible damage or signal degradation occurs.

Updates and Revisions:
- Product specifications subject to change based on manufacturing improvements or compatibility updates.
- Latest documentation and compatibility notes available on Rayon’s official website.

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Summary
The Rayon A401 Cable (DB37f to 4×DB25m, 0.2 m) is a precision-engineered breakout cable designed for multi-channel serial communication systems, particularly the RS4232-4 interface box. It provides a compact, reliable, and shielded connection solution for distributing serial signals from a single DB37 interface to four DB25 ports. With robust construction, compliance with international standards, and ease of installation, the A401 is ideal for industrial automation, laboratory instrumentation, and communication system integration where dependable serial connectivity is essential.