Yokogawa ALR121-S01 Serial Communication Module

The Yokogawa ALR121-S01 is a high-performance serial communication module designed to enable seamless communication between a Safety Control Station (SCS) and various subsystems. It features two communication ports: one for RS-422 and one for RS-485. This flexibility allows the module to integrate smoothly into diverse industrial automation systems, ensuring stable, reliable, and efficient communication in real-time control and monitoring environments.

Technical Specifications of the Yokogawa ALR121-S01

Specification	Details
Product Type	Serial Communication Module
Model	ALR121-S01
Interface	RS-422/RS-485 (4-wire system)
Connection Methods	Point-to-point (RS-422), Multipoint (RS-485)
Communication Function	Half-duplex
Synchronization Method	Start-stop synchronization
Transmission Speed	1200, 2400, 4800, 9600, 19200, 38400 bps
Transmission Code	Binary
Character Length	8 bits (fixed for Modbus slave and subsystem communication)
Stop Bit Length	1 or 2 bits (fixed to 1 bit for subsystem communication)
Parity Check	None, Even, Odd
Lag Time After Data Transmission	1 ms
Transmission Distance	15m (RS-422), 1200m (RS-485)
Installation Method	Mounted on S2SC70S, SSC60S, SSC50S, SSC57S, or SNB10DI/o
Wiring	D-sub-9-pin (female x 2 ports), Clamped with M4 screws (5 poles x 2 ports)
Communication Functions	Modbus slave communication, Subsystem communication
Current Consumption	0.5 A
Weight	Approx. 0.34 kg

Key Features of the Yokogawa ALR121-S01

Dual Communication Ports: The ALR121-S01 provides two communication ports, one for RS-422 and another for RS-485. This feature allows for seamless integration into various industrial systems.
Modbus Communication Support: Supporting Modbus slave communication, this module allows Safety Control Stations (SCS) to operate independently from the Modbus master system. As a result, it increases flexibility and simplifies system architecture.
Flexible Transmission Speed: You can adjust transmission speeds from 1200 bps to 38400 bps. This flexibility accommodates a wide range of industrial applications, ensuring the module performs optimally under various conditions.
Extended Transmission Range: The ALR121-S01 offers impressive transmission distances: 15 meters for RS-422 and 1200 meters for RS-485. This ensures stable communication, even across large facilities.
Simple Installation: Easily mount the ALR121-S01 on compatible Yokogawa control units such as S2SC70S, SSC60S, SSC50S, SSC57S, or SNB10DI/o. The module’s straightforward installation process reduces setup time and complexity.
Compact and Durable: With a compact design and a weight of just 0.34 kg, the ALR121-S01 fits seamlessly into tight control panel spaces. It is built to withstand harsh industrial environments, including temperature extremes and high vibration.

Applications

Industrial Automation: The ALR121-S01 enables communication between Safety Control Stations (SCS) and subsystems in automated industrial environments, ensuring efficient process management and data exchange.
Modbus-based Control Systems: Perfect for Modbus-based networks, the ALR121-S01 facilitates smooth integration of Modbus slave communication, enhancing communication reliability and reducing system complexity.
Safety and Process Control: In safety-critical and process control systems, this module ensures reliable data transmission even under demanding conditions, such as temperature extremes and high levels of vibration.