{"product_id":"yokogawa-alr121-s50-s1-rs-485-communication-modules","title":"Yokogawa ALR121-S50-S1 RS-485 Communication Modules","description":"\u003ch2\u003eYokogawa ALR121-S50-S1 Serial Communication Module\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eYokogawa ALR121-S50-S1\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003eALR121\u003c\/strong\u003e Serial Communication Module, operates as a dedicated hardware component for serial data exchange with external subsystems within CENTUM VP, CS 3000, and ProSafe-RS platforms.\u003c\/p\u003e\n\u003ch3\u003eSuffix Breakdown \u0026amp; Model Matrix\u003c\/h3\u003e\n\u003cp\u003eThe suffix structure defines physical protection and revision levels:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eALR121\u003c\/strong\u003e: Base series code for dual-port serial communication interface cards.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e-S\u003c\/strong\u003e: Standard hardware type.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e5\u003c\/strong\u003e: Non-explosion-protected variant.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e0\u003c\/strong\u003e: Basic hardware functional revision.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eS1\u003c\/strong\u003e: System-specific firmware\/hardware variant.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eALR121-S50-S1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eYokogawa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eJapan \/ USA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.30 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e3.28 x 14.29 x 13.00 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e-20 deg C to +70 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStorage Temp\u003c\/td\u003e\n\u003ctd\u003e-20 deg C to +70 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e0.5 A at 5 VDC (~2.5 W typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication Standard\u003c\/td\u003e\n\u003ctd\u003eRS-422 \/ RS-485\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePorts\u003c\/td\u003e\n\u003ctd\u003e2 (dual-port design)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTopology\u003c\/td\u003e\n\u003ctd\u003ePoint-to-point (RS-422) \/ Multipoint (RS-485)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBaud Rate\u003c\/td\u003e\n\u003ctd\u003e300 bps to 115.2 kbps (configurable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission Mode\u003c\/td\u003e\n\u003ctd\u003eHalf-duplex asynchronous\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSupported Protocols\u003c\/td\u003e\n\u003ctd\u003eModbus RTU, proprietary \/ custom protocols\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIsolation\u003c\/td\u003e\n\u003ctd\u003eChannel-to-channel and system-to-channel isolation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnector Type\u003c\/td\u003e\n\u003ctd\u003eTerminal-type RS-422 \/ RS-485 interface\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInstallation\u003c\/td\u003e\n\u003ctd\u003ePlug-in rack mount, hot-swappable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eChannel-to-Channel Isolation and Loop Performance\u003c\/h3\u003e\n\u003cp\u003eThe unit incorporates channel-to-channel and system-to-channel isolation across both communication channels to suppress common-mode ground loops and electrical interference. Designed for sub-system integration, the module facilitates deterministic polling over RS-422 and RS-485 physical layers. Cold junction compensation (CJC) circuits are omitted on this digital data transmission interface, maximizing processing bandwidth for protocol frame parsing up to 115.2 kbps.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: Does the ALR121-S50-S1 support hot-swapping during active system operations? A: Yes, the module features hot-swappable plug-in capability, allowing replacement directly into an energized node rack without disrupting backplane communications.\u003c\/p\u003e\n\u003cp\u003eQ: What physical network topologies are supported by the dual serial ports? A: Port 1 and Port 2 support point-to-point wiring when configured for RS-422 and multipoint bus structures when configured for RS-485 half-duplex communication.\u003c\/p\u003e\n\u003cp\u003eQ: How is backplane power managed for the module? A: The card draws power directly from the system node backplane, requiring 0.5 A at 5 VDC for a nominal power dissipation of ~2.5 W.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eMount the module into an open slot of a compatible node rack until the backplane connectors seat firmly. Tighten top and bottom retaining screws to prevent vibration-induced disengagement. Route RS-422\/RS-485 field wiring using shielded twisted-pair cables, ensuring signal ground shields connect to the designated earth ground bus at one end only to eliminate ground loops. Install termination resistors across the physical end nodes of RS-485 daisy chains to eliminate signal reflections. Verify that conduit entries maintain a minimum engagement of 5 full NPT threads where rigid metal conduit connects to the field junction enclosure.\u003c\/p\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":43815681359962,"sku":"ALR121-S50-S1","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/5957\/0778\/files\/766..jpg?v=1786324679","url":"https:\/\/www.spareoil.com\/products\/yokogawa-alr121-s50-s1-rs-485-communication-modules","provider":"SpareOil Automation","version":"1.0","type":"link"}