{"product_id":"yokogawa-alr121-s50-serial-communication-module","title":"Yokogawa ALR121-S50 Serial Communication Module","description":"\u003ch2\u003e\u003cstrong\u003eDescription\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eYokogawa ALR121‑S50\u003c\/strong\u003e is a dual‑port serial communication module designed for CENTUM VP and ProSafe‑RS systems. It supports RS‑422\/RS‑485 interfaces and provides Modbus slave and subsystem communication functions for stable industrial data exchange.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eHardware Specifications\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003ctd\u003eALR121‑S50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eYokogawa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOrigin\u003c\/th\u003e\n\u003ctd\u003eJapan\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003eApprox. 0.34 kg (typical ALR121 series weight)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDimensions\u003c\/th\u003e\n\u003ctd\u003eStandard Yokogawa I\/O module form factor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOperating Temp\u003c\/th\u003e\n\u003ctd\u003eISA G3 rating (–20 to +70 °C, maintenance purpose only)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower Consumption\u003c\/th\u003e\n\u003ctd\u003eCurrent consumption 0.5 A (series‑standard)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eModule Type\u003c\/th\u003e\n\u003ctd\u003eSerial Communication Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eInterface\u003c\/th\u003e\n\u003ctd\u003eRS‑422 \/ RS‑485 (4‑wire system)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePorts\u003c\/th\u003e\n\u003ctd\u003e2 serial communication ports\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCommunication Functions\u003c\/th\u003e\n\u003ctd\u003eModbus slave communication; subsystem communication\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eExplosion Protection\u003c\/th\u003e\n\u003ctd\u003eCode “5” – no explosion protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSuffix Code\u003c\/th\u003e\n\u003ctd\u003eS50 (Standard type, no explosion protection)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMounting\u003c\/th\u003e\n\u003ctd\u003eRack‑mounted within CENTUM VP \/ ProSafe‑RS I\/O nests\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePCB Coating\u003c\/th\u003e\n\u003ctd\u003eConformal coating (model‑dependent)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eProduct Type\u003c\/th\u003e\n\u003ctd\u003eSerial Communication Modules\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch2\u003e\u003cstrong\u003eFunctional Description\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe ALR121‑S50 module provides two isolated serial communication ports supporting RS‑422\/RS‑485 4‑wire operation. It enables Modbus slave communication and subsystem data exchange within Yokogawa control architectures. As part of the ALR121 family, the S50 suffix indicates a \u003cstrong\u003estandard‑type module\u003c\/strong\u003e with \u003cstrong\u003eno explosion protection\u003c\/strong\u003e, suitable for general‑purpose control‑room environments. The module routes serial data to the control processor through the backplane, ensuring deterministic communication timing for subsystem integration.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What communication protocols does ALR121‑S50 support?\u003c\/strong\u003e It supports Modbus slave communication and Yokogawa subsystem communication functions.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What does the S50 suffix mean?\u003c\/strong\u003e “S” = Standard type “5” = No explosion protection “0” = Standard environmental rating\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can ALR121‑S50 be hot‑swapped?\u003c\/strong\u003e No. Serial communication modules must be inserted or removed only when the I\/O segment is de‑energized.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eField Installation Guidelines\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMaintain shield continuity on serial communication wiring to reduce noise.\u003c\/li\u003e\n\u003cli\u003eEnsure correct polarity and wiring for RS‑422\/RS‑485 4‑wire connections.\u003c\/li\u003e\n\u003cli\u003eAvoid routing serial lines near high‑current conductors to prevent interference.\u003c\/li\u003e\n\u003cli\u003eVerify backplane connectors are fully seated before energizing the system.\u003c\/li\u003e\n\u003cli\u003eInspect terminal surfaces for contamination or oxidation prior to installation.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":47904344441022,"sku":"ALR121-S50","price":3000.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0725\/1145\/5422\/files\/screenshot_2026-06-11_15-31-20_f51f589b-a27f-4cbe-a813-e8a78f7b832a.png?v=1781164448","url":"https:\/\/www.autooiltech.com\/products\/yokogawa-alr121-s50-serial-communication-module","provider":"AutoOilTech Limited","version":"1.0","type":"link"}