ALR121-S51 Yokogawa Serial Module | ALR Series Safety System Communication

Description

Product Introduction

• Brand: Yokogawa
• Model: ALR121-S51
• Series: ALR Safety Communication Series
• ALR121-S51 is a serial communication module for safety systems.
• It supports stable data exchange over long distances.
• It works with Yokogawa Centum VP architectures.

Key Product Advantages

• Supports RS-422 and RS-485 communication.
• Designed for safety control systems.
• Stable data transfer in noisy environments.
• Flexible speed settings for field devices.
• Long cable distance reduces wiring cost.

Hardware Communication Capabilities

• Interface Type
  • RS-422 four-wire system
  • RS-485 multipoint system
• Communication Mode
  • Point-to-point for RS-422
  • Multi-drop for RS-485
  • Half-duplex operation
• Protocol Support
  • Modbus slave communication
  • Subsystem internal communication

Transmission Performance

• Transmission speed from 1200 to 38400 bps.
• Binary data format for fast processing.
• Start-stop synchronization ensures data integrity.
• Maximum transmission distance up to 1200 meters.
• Lag time after transmission is only 1 ms.

Signal and Data Settings

• Character length fixed at 8 bits.
• Stop bits support 1 or 2 bits.
• Parity options include none, even, or odd.
• Optimized for Modbus slave communication.

Mechanical and Electrical Data

• Current consumption: 0.5 A.
• Weight: approximately 0.34 kg.
• Dual D-sub 9-pin female connectors.
• Terminal block secured with M4 screws.

Configuration Breakdown

• ALR121
  • -S: Standard configuration
    • 5: No explosion protection
    • 1: ISA Standard G3 coating

System Compatibility

• Supported SCS units include SSC60, SSC50, SSC57, SSC10.
• Compatible with SNB10D base units.
• Supports AKB131, AKB132, AKB135, and AKB136 cables.

Software and Engineering Requirements

• CFS1300 safety function package for SSC60 systems.
• CFS1100 safety package for SSC50 and SSC10.
• CFS1170 safety package for SSC57 platforms.
• CHS5100 engineering tool for configuration.

Module Capacity Rules

• Up to 2 modules per SCS for Modbus slave use.
• Up to 4 modules per SCS for subsystem communication.

Installation Guidance

• Mounts directly on supported SCS units.
• No special tools required.
• Clear labeling reduces wiring errors.

Typical Industrial Applications

• Safety system data exchange.
• Field device communication.
• Distributed control architectures.
• Process automation safety networks.

Warranty and Logistics

• 12-month hardware warranty.
• Carefully packed for export shipping.
• Delivery via FedEx, UPS, or DHL.

Professional FAQ

• Is ALR121-S51 suitable for long-distance wiring
• Yes. RS-485 allows stable transmission up to 1200 meters.
• How do I choose between RS-422 and RS-485
• Use RS-422 for point links. Use RS-485 for multiple devices.
• Does this module support safety communication
• Yes. It is designed for safety control systems.
• Can I mix Modbus and subsystem communication
• Yes. Selection depends on system configuration.
• What should I consider before ordering
• Confirm SCS type, coating option, and communication method.

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