{"product_id":"alr121-s51-yokogawa-centum-vp-serial-communication-module","title":"ALR121-S51 | Yokogawa | CENTUM VP Serial Communication Module","description":"\u003ch3\u003eProduct Overview\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eYokogawa ALR121-S51\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eserves as a robust serial communication gateway for the CENTUM VP and CS 3000 Distributed Control Systems (DCS). This module establishes high-integrity data links between the Field Control Station (FCS) and external subsystems using RS-422 or RS-485 protocols. It facilitates the integration of third-party hardware, such as motor control centers, smart analyzers, and PLCs, into a centralized management environment. We supply this unit as\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e100% Brand New and Original\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eto ensure mission-critical stability in demanding industrial facilities.\u003c\/p\u003e\n\u003ch3\u003ePart Number Breakdown\u003c\/h3\u003e\n\u003cp\u003eThe ALR121-S51 utilizes a specific suffix structure to define its hardware grade and functional specialization:\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003ctd\u003e\u003cstrong\u003eSuffix Code\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eFunctional Definition\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eALR121\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eSerial Communication Module (RS-422\/RS-485)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003e-S\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eStandard Type Hardware\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003e5\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eNon-explosion protected variant\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003e1\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eBasic functional revision with specific system compatibility\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cp\u003eThe ALR121-S51 manages complex half-duplex communication cycles with high precision.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eInterface Port:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eRS-422 \/ RS-485 (4-wire system supported).\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eConnection Topology:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ePoint-to-point (RS-422) or Multipoint (RS-485).\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eCommunication Mode:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eHalf-duplex.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eSynchronization:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eStart-stop synchronization.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eTransmission Speeds:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSupports 1200, 2400, 4800, 9600, 19200, and 38400 bps.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eUnit Weight:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e0.34 kg.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGuaranteed 100% Brand New and Original.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEngineering Advantages\u003c\/h3\u003e\n\u003cp\u003eThe ALR121-S51 addresses specific technical hurdles in field-level communication:\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eFlexible Network Topology:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe module supports both Point-to-point and Multipoint architectures. This allows engineers to choose between dedicated high-speed links for critical analyzers or daisy-chained RS-485 networks to reduce overall cabling costs for multi-device clusters.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eDeterministic Signal Integrity:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIn electrically noisy environments, the 4-wire RS-422\/485 differential signaling rejects common-mode interference. This ensures accurate data polling even when the communication lines run parallel to high-voltage power cables in industrial trays.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eStart-Stop Synchronization Efficiency:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe module utilizes asynchronous start-stop synchronization to manage data packets without requiring a common clock signal between the DCS and the field device. This simplifies the integration of third-party hardware that utilizes diverse timing standards.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOptimized Power Use:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAt a weight of only 0.34 kg, the module features a solid-state design that minimizes heat generation within the FCS rack. This prevents thermal hotspots and extends the lifespan of adjacent processor modules in high-density cabinet installations.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFAQs\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eCan the ALR121-S51 communicate with standard 2-wire RS-485 devices?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe ALR121-S51 specifies a 4-wire system for maximum stability. While it primarily supports 4-wire configurations, you can often bridge the TX and RX pairs for 2-wire operation depending on the specific field device requirements and software settings.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the maximum number of devices I can connect in a Multipoint setup?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe RS-485 standard technically supports up to 32 nodes. However, for the ALR121-S51, we recommend calculating the total bus impedance and baud rate to maintain the 38400 bps maximum speed across the entire segment.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eIs this module suitable for high-speed motor control?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. With transmission speeds reaching 38400 bps and a dedicated internal buffer for start-stop synchronization, it effectively handles real-time status polling for VFDs and motor control centers.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this product ship with the original factory seal?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAbsolutely. We supply the ALR121-S51 as\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e100% Brand New\u003c\/strong\u003e. Every unit arrives in its original Yokogawa factory packaging, featuring full serial number traceability and the manufacturer's original protective seals.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":52824134418741,"sku":"ALR121-S51","price":66.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0973\/7630\/5461\/files\/ALR121-S00_82343adb-31a7-44c7-b630-3d1beace8d72.png?v=1778038084","url":"https:\/\/www.5gplc.com\/products\/alr121-s51-yokogawa-centum-vp-serial-communication-module","provider":"High Five PLC Solution Limited","version":"1.0","type":"link"}