ALR121-S00 S1 Yokogawa Safety Control Station Card

Product Overview

The Yokogawa ALR121-S00 S1 functions as a high-reliability, deterministic serial communication gateway inside ProSafe-RS Safety Control Stations (SCS). This industrial interface module establishes secure data links between third-party systems and the primary safety network using standard RS-422 and 4-wire RS-485 physical layer protocols. By operating with complete electrical and logical isolation from the critical safety loop, the module allows secondary devices, sequencers, and sub-systems to read variables without introducing risks to the protective logic.

Part Number Breakdown

Yokogawa applies distinct classification suffixes to indicate structural choices and chemical resistance treatments on their safety components. The ALR121 code breaks down as follows:

• ALR121: Base model for serial communication interface module (RS-422/RS-485)

• -S: Standard hardware platform architecture

• 0: Always 0 (Standard internal design designation)

• 0: Basic operational configuration parameter set

• S1: Class G3 harsh environment conformal coating compliance enhancement

Technical Specifications

This 100% brand new, original Yokogawa safety-system component arrives in factory-sealed packaging. All parameter metrics utilize standard ASCII formatting.

• Model: ALR121-S00 S1

• Module Type: Serial Communication Interface Module

• Physical Ports: RS-422 (point-to-point mode) and RS-485 (multipoint, 4-wire mode)

• Embedded Software Functions: Modbus slave protocol, subsystem interface link

• Safety Integration: Interference-free design with the primary safety loop

• System Mounting Base: ProSafe-RS Safety Control Station (SCS) slot

• Required I/O Wiring: 3-pair shielded cable (Yokogawa AKB161 or AKB162)

• Internal Current Consumption: 0.5 A

• Environmental Protection: ISA Standard G3 conformal coating specification

• Net Weight: 0.34 Kg

• Physical Scale (W x H x D): 3.2 x 14.1 x 13 cm

• Global Regulatory Certifications: CE, ISO

• Country of Origin: Japan

Engineering Advantages

• Guarantees Zero Safety Loop Interference: Connecting non-safety diagnostic gear or external controllers directly to an active Emergency Shutdown (ESD) system can compromise system integrity. The ALR121-S00 S1 employs an automated hardware firebreak mechanism that enforces strict "interference-free" separation. External Modbus polling or hardware faults on the serial line cannot disrupt or delay the internal processing routines of the safety loop.

• Resists Corrosive Chemical Gas Ingress: Industrial control rooms at oil refineries, wastewater treatment facilities, and paper mills often expose electronics to airborne sulfur dioxide, chlorine, and moisture, causing rapid tin-whisker growth and terminal oxidation. The S1 designation specifies an advanced conformal coating that fulfills the strict ISA Standard G3 rating. This protective layer seals the delicate copper traces, eliminating environmental degradation.

• Unifies Multi-Vendor Device Architectures: Integrating legacy PLC sequencers and specialized analyzers into a centralized Yokogawa ProSafe-RS safety matrix often requires expensive custom software drivers. The ALR121-S00 S1 runs an native Modbus slave protocol across its RS-485 lines. This standard industrial language allows the module to map variables smoothly from disparate hardware directly into the Safety Control Station data registers.

• Minimizes Signal Losses Over Long Cable Distances: High-frequency digital communications inside sprawling manufacturing facilities frequently suffer from electromagnetic interference and attenuation when routed over long paths. This module utilizes a robust 4-wire balanced RS-485 architecture coupled with heavy 3-pair shielded AKB161/AKB162 cabling. This combination cancels out external common-mode noise, keeping communications reliable across lengthy cable runs.

FAQs

• Q: Is this ALR121-S00 S1 module brand new, and how do you guarantee its authenticity?A: Yes. We supply this product as a 100% brand new, genuine, and original factory item direct from Yokogawa Japan. The module arrives wrapped inside its factory antistatic material within the original unopened manufacturer box, displaying matching serial numbers, production codes, and quality check inserts.

• Q: Can I use this serial module to write safety-critical commands into the ProSafe-RS system from an external HMI?A: No. The ALR121-S00 S1 primarily handles monitoring, diagnostics, and data collection tasks as a Modbus slave. Because it utilizes an interference-free hardware design to protect the Safety Control Station, it does not permit unvalidated external serial inputs to alter or override active safety interlocks or emergency shutdown routines.

• Q: Which specific cables must I procure to hook this module up to our marshalling panel?A: For stable communication and electrical compliance, you must use Yokogawa's matching 3-pair shielded system cables, part numbers AKB161 or AKB162. These cables feature the exact impedance characteristics and connector hoods needed to lock into the module's front faceplate.