Technical Specifications
Main Features and Advantages
The YOKOGAWA ALR121-S51 is a robust communication solution that offers a distinct advantage through its dual focus on high availability and enhanced protection. Its primary feature is the integrated surge protector, which shields the module and the entire system from damaging electrical surges and transients, a common risk in many industrial environments. This added layer of protection significantly increases the module’s reliability and longevity. In addition to this physical safeguard, the ALR121-S51 is designed for redundant operation. When used in a redundant pair, it ensures a seamless, active-standby failover, guaranteeing that communication with external serial devices remains continuous even in the event of a module or link failure. This combination of redundancy and surge protection makes the ALR121-S51 an exceptionally reliable component for critical control applications. The module also supports a range of serial protocols (RS-232, RS-422, RS-485) and offers two independent communication ports, providing great flexibility for integrating a variety of third-party equipment. Its deep integration with the CENTUM VP system allows for simplified configuration and diagnostics, and its on-board LEDs provide quick visual status checks, making it easier to maintain and troubleshoot.
Application Field
The YOKOGAWA ALR121-S51 module is an ideal solution for industrial applications that demand both high-availability and robust protection from environmental factors. Its main areas of use are in sectors such as oil and gas, power generation, and remote site monitoring, where electrical disturbances are a frequent concern. In these fields, the ALR121-S51 is used to connect the CENTUM VP DCS to critical instruments like analyzers, flow computers, and specialized monitoring devices that use serial communication. The built-in surge protection is particularly valuable in outdoor installations or facilities with heavy machinery, where electrical noise and surges are common. For example, in a remote oil and gas facility, a redundant pair of ALR121-S51 modules can ensure a continuous and protected data link to a flow computer, guaranteeing that essential production data is not lost. The redundancy ensures that even if one module is affected by an issue, the other takes over instantly, preventing any disruption. The module’s versatility in handling multiple serial protocols also makes it suitable for integrating a diverse range of legacy or specialized devices into a modern, centralized control system.
Related Products
ALR121-S50: This is the redundant version of the ALR121, but it does not include the built-in surge protection of the ALR121-S51, making the latter a more robust choice for harsh environments. ALP121-S51: This module provides redundant communication with surge protection for the PROFIBUS-DP protocol, highlighting a key difference in communication standards from the serial-based ALR121-S51. ALP121-S00: The standard, non-redundant PROFIBUS-DP communication module for CENTUM VP. AFV30S: The Field Control Unit (FCU) for the CENTUM VP system, which serves as the host for the ALR121-S51 module. ANB10: An ESB Bus Node Unit that can house the ALR121-S51 module, allowing for the extension of serial communication from the main Field Control Unit.
Installation and Maintenance
Pre-installation preparation: Before installing a pair of YOKOGAWA ALR121-S51 modules, ensure that the CENTUM VP Field Control Station (FCS) is completely de-energized to prevent damage. The system software must be compatible with the modules’ firmware. For redundant installations, place both ALR121-S51 modules in adjacent slots as specified in the manual. Due to the integrated surge protection, it is critical to ensure proper grounding of the module and the chassis as per the installation guidelines to maximize its effectiveness. Prepare the necessary serial cables and configure them for the correct protocol and communication parameters.
Maintenance recommendations: Routine maintenance for the ALR121-S51 modules focuses on software diagnostics and external device health checks. Use the CENTUM VP’s monitoring functions to check the communication status and performance. The on-board LED indicators on each ALR121-S51 provide a quick visual check of its operational status. In the event of a failure, the system will automatically switch to the standby unit, but the failed ALR121-S51 module must be replaced promptly to restore full redundancy. When replacing a module, follow the hot-swapping procedure as outlined in the manual to minimize system interruption. For physical care, use a soft, dry cloth to remove dust from the module’s exterior and avoid using liquid cleaners.
Product Guarantee
Yokogawa’s commitment to quality and reliability is reinforced by the comprehensive product guarantee for the ALR121-S51. Each module is manufactured to the highest standards, ensuring its performance and longevity. The product is backed by a warranty that covers manufacturing defects, providing customers with confidence in their investment. In addition to the standard warranty, customers have access to Yokogawa’s global network of expert technical support, which is available to assist with all aspects of the module’s operation, from initial installation to troubleshooting and system optimization. This commitment to robust after-sales service and technical expertise ensures that users can rely on the performance and durability of the ALR121-S51 to maintain the stability and efficiency of their mission-critical automation systems.
ALLEN BRADLEY 1756-A17 RACK W/ POWER SUPPLY & MODULE
ALLEN BRADLEY 1756-A10 RACK W/ POWER SUPPLY & MODULES
ALLEN BRADLEY 1756-A10 RACK W/ POWER SUPPLY & MODULES
HOFFMAN 38305B1 700 CFM CENTRIFUGAL EXHAUSTER
ABB EHW250WC2P-1L SIZE W5 WELDING CONTACTOR NIB *
BUSSMANN LPJ-15SP LOW PEAK FUSES, LOT OF 1015, NNB
BUSSMANN LPJ-4SP LOW PEAK FUSES, LOT OF 736, NNB
BUSSMANN LPJ-30SP LOW PEAK FUSES, LOT OF 1308, NNB
BUSSMANN LPJ-5SP LOW PEAK FUSES, LOT OF 1090, NNB
BUSSMANN LPJ-20SP LOW PEAK FUSES, LOT OF 1030, NNB
BUSSMANN LPJ-6SP LOW PEAK FUSES, LOT OF 895, NNB
ALLEN BRADLEY 2711-T10C15 SER B REV C PANELVIEW 1000 *
ALLEN BRADLEY 2711-T10C15 SER B REV D PANELVIEW 1000 *
ALLEN BRADLEY 2711-K10C1 SER C REV B PANELVIEW 1000
ALLEN BRADLEY 2711-T10C15 SER B REV B PANELVIEW 1000 *
ALLEN BRADLEY 2711-T10C15X SER B REV E PANELVIEW 1000 *
FANUC A05B-2301-C303 TEACH PENDANT
