{"product_id":"yokogawa-alr121-s51-s1-serial-communication-module-rs-422-rs-485","title":"Yokogawa ALR121-S51 S1 Serial Communication Module RS-422\/RS-485","description":"\u003ch3 class=\"\"\u003eProduct Overview\u003c\/h3\u003e\n\u003cp\u003e\u003cspan class=\"\"\u003eThe Yokogawa ALR121-S51 S1 is a high-reliability Serial Communication Module designed for the CENTUM VP and CS 3000 Distributed Control Systems (DCS).\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eThis module serves as a critical bridge between the Yokogawa Field Control Station (FCS) and external subsystem devices,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003esuch as PLCs,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003emotor control centers (MCC),\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eand analytical instruments.\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eBy supporting RS-422 and RS-485 interfaces,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ethe ALR121-S51 S1 enables seamless data integration across various industrial protocols.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"\"\u003eA core feature of the ALR121-S51 S1 is its support for dual-redundancy.\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eWhen two modules are installed in a paired configuration,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ethe system maintains a \"Hot Standby\" state.\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eIn the event of a primary module failure or a detected communication error,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ethe system executes a millisecond-level failover to the standby unit,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eensuring uninterrupted process visibility and control.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 class=\"\"\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eManufacturer:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eYokogawa\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eModel Number:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eALR121-S51 S1\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eModule Type:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eSerial Communication Module\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eInterface:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eRS-422 \/ RS-485 (2 ports)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eTransmission Speed:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003e300 bps to 115.\u003c\/span\u003e\u003cspan class=\"\"\u003e2 kbps\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eConnection Method:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eD-sub 9-pin (female)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eMax. Transmission Distance:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003e1200 meters (Total extended length)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eRedundancy:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eSupports Dual-Redundant configuration (hot-swappable)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eCurrent Consumption:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eMax.\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003e0.\u003c\/span\u003e\u003cspan class=\"\"\u003e5 A (at 5V DC)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eOperating Temperature:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003e-20°C to +70°C\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eDimensions:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003e14 cm x 13 cm x 3.\u003c\/span\u003e\u003cspan class=\"\"\u003e2 cm\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eWeight:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003e0.\u003c\/span\u003e\u003cspan class=\"\"\u003e3 kg\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eOrigin:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eJapan\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 class=\"\"\u003eKey Technical Characteristics\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eAdvanced Redundancy Management:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eFeatures synchronized data memory between active and standby modules.\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eThis ensures that the control station always has access to the most recent data set immediately following a failover transition.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eMulti-Protocol Support:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eDesigned to handle complex communication tasks including Modbus RTU (Master\/Slave) and other general-purpose serial communication through customized software drivers.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eFault-Tolerant Architecture:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eEach of the two ports operates independently,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eproviding versatile wiring options and preventing a single port failure from disabling the entire module's communication capability.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eIntelligent Self-Diagnostics:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eIntegrated hardware watchdog timers and communication health monitoring allow the module to self-identify internal errors or line faults,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003etriggering automatic recovery or system alerts.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong class=\"\"\u003eIndustrial Hardening:\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eCertified for use in harsh petrochemical and energy environments,\u003c\/span\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ewith ISA G3 compliant protection against corrosive gases and a wide thermal operating envelope.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eHot-Swap Capability:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eModules can be replaced online without shutting down the Field Control Unit (when used in a redundant pair), minimizing downtime during maintenance or hardware upgrades.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":45519051063469,"sku":"ALR121-S51 S1","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/yokogawa-alr121-s51-s1-communication-module-bputhbzukgr.jpg?v=1766985774","url":"https:\/\/www.maxwellplc.com\/products\/yokogawa-alr121-s51-s1-serial-communication-module-rs-422-rs-485","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}