{"product_id":"alf111-s50-yokogawa-alf111-series-fieldbus-communication-module","title":"ALF111-S50 Yokogawa ALF111 Series Fieldbus Communication Module","description":" \u003ch3\u003e\u003cstrong\u003eYokogawa ALF111-S50 FOUNDATION Fieldbus Communication Module\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eALF111-S50\u003c\/strong\u003e is a Yokogawa FOUNDATION Fieldbus communication module for industrial control system integration. It provides four fieldbus ports, with each port supporting one low-speed voltage-mode segment. The module operates at 31.25 kbps and supports LAS and clock master functions.\u003c\/p\u003e\n\n\u003cp\u003eEngineers can use the ALF111-S50 to connect field instruments with compatible Yokogawa control system nodes. Its dual-redundancy configuration supports installations requiring improved communication availability. Correct segment planning, device-count verification, and termination settings remain essential during commissioning.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e1. Hardware Profile and Operating Limits\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eEngineering Relevance\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eYokogawa\u003c\/td\u003e\n\u003ctd\u003eIndustrial control and fieldbus integration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eALF111-S50\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eComplete ordering code\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule type\u003c\/td\u003e\n\u003ctd\u003eFOUNDATION Fieldbus Communication Module\u003c\/td\u003e\n\u003ctd\u003eField-device communication interface\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFieldbus interface\u003c\/td\u003e\n\u003ctd\u003eLow-speed voltage mode\u003c\/td\u003e\n\u003ctd\u003eFOUNDATION Fieldbus segment communication\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of ports\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003eSupports four separate segments\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSegment allocation\u003c\/td\u003e\n\u003ctd\u003e1 segment per port\u003c\/td\u003e\n\u003ctd\u003eFour ports do not represent one shared segment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission speed\u003c\/td\u003e\n\u003ctd\u003e31.25 kbps\u003c\/td\u003e\n\u003ctd\u003eFieldbus communication rate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl I\/O capacity\u003c\/td\u003e\n\u003ctd\u003eMaximum 48 points per segment\u003c\/td\u003e\n\u003ctd\u003eObserve the specified scanning-cycle conditions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFieldbus device capacity\u003c\/td\u003e\n\u003ctd\u003eMaximum 32 units per segment\u003c\/td\u003e\n\u003ctd\u003eThe ALF111 counts as one unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication functions\u003c\/td\u003e\n\u003ctd\u003eLAS and clock master\u003c\/td\u003e\n\u003ctd\u003eSupports fieldbus link scheduling and time coordination\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRedundancy\u003c\/td\u003e\n\u003ctd\u003eDual-redundancy configuration supported\u003c\/td\u003e\n\u003ctd\u003eTwo ALF111 modules can occupy designated adjacent slots in the same node unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent consumption\u003c\/td\u003e\n\u003ctd\u003e0.5 A or less\u003c\/td\u003e\n\u003ctd\u003eVerify node power capacity and total module loading\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWithstanding voltage\u003c\/td\u003e\n\u003ctd\u003e1500 V AC for 1 minute\u003c\/td\u003e\n\u003ctd\u003eSpecified isolation withstand capability\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApproximate weight\u003c\/td\u003e\n\u003ctd\u003e0.40 kg\u003c\/td\u003e\n\u003ctd\u003eUseful for handling and inventory planning\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003e\u003cstrong\u003e2. Configuration Breakdown — Ordering Code Tree\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eComplete model: ALF111-S50\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eALF111\u003c\/strong\u003e — FOUNDATION Fieldbus Communication Module\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e-S\u003c\/strong\u003e — Standard type\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e5\u003c\/strong\u003e — Without explosion protection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e0\u003c\/strong\u003e — Basic type\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eOrdering guidance:\u003c\/strong\u003e Match the full suffix code against the installed system requirements. The “5” code indicates no explosion protection, so do not select this version for an installation requiring module-level explosion protection.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e3. Port Architecture and Segment Planning\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eConfiguration Item\u003c\/th\u003e\n\u003cth\u003eSpecified Limit\u003c\/th\u003e\n\u003cth\u003eSelection or Design Check\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable fieldbus ports\u003c\/td\u003e\n\u003ctd\u003e4 ports\u003c\/td\u003e\n\u003ctd\u003eMap each port to its intended fieldbus segment.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSegments per port\u003c\/td\u003e\n\u003ctd\u003e1 segment\u003c\/td\u003e\n\u003ctd\u003ePlan device allocation and wiring independently for each segment.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl I\/O points\u003c\/td\u003e\n\u003ctd\u003eMaximum 48 per segment\u003c\/td\u003e\n\u003ctd\u003eConfirm the applicable scanning-cycle configuration.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHigh-speed scanning allocation\u003c\/td\u003e\n\u003ctd\u003eUp to 6 I\/O points\u003c\/td\u003e\n\u003ctd\u003eThe specified ER bus configuration supports high- and medium-speed scanning cycles under this condition.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFieldbus devices\u003c\/td\u003e\n\u003ctd\u003eMaximum 32 units per segment\u003c\/td\u003e\n\u003ctd\u003eInclude the ALF111 in the stated unit count.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBuilt-in termination\u003c\/td\u003e\n\u003ctd\u003eSwitchable terminators\u003c\/td\u003e\n\u003ctd\u003eCheck segment-end termination against the approved network design.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003eDo not treat the 48-point control I\/O limit and 32-unit fieldbus limit as interchangeable. They describe different constraints. Verify both limits for each segment before finalizing the instrument list.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e4. Compatible Platforms and Typical Applications\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eThe ALF111 supports installation on the following specified Yokogawa node or base-unit families. Confirm the exact hardware variant and slot requirements before ordering.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eANB10 series\u003c\/li\u003e\n\u003cli\u003eANB11 series\u003c\/li\u003e\n\u003cli\u003eAFV30 series\u003c\/li\u003e\n\u003cli\u003eAFV40 series\u003c\/li\u003e\n\u003cli\u003eA2FV50 series\u003c\/li\u003e\n\u003cli\u003eA2FV70 series\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eTypical engineering applications include:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProcess instrumentation:\u003c\/strong\u003e Connecting compatible FOUNDATION Fieldbus instruments to a supported Yokogawa control node.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDistributed control systems:\u003c\/strong\u003e Integrating field-device communication into process control architectures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMulti-segment installations:\u003c\/strong\u003e Distributing field instruments across four independently planned fieldbus segments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRedundant control configurations:\u003c\/strong\u003e Supporting installations that require two ALF111 modules in designated adjacent slots within the same node unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlant upgrades and spare replacement:\u003c\/strong\u003e Replacing a matching module while preserving the approved node configuration and fieldbus design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eActual compatibility depends on the control system model, node hardware, software revision, slot arrangement, and fieldbus configuration. Confirm these details before purchasing a replacement.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e5. Installation and Commissioning Checklist\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eVerify the node:\u003c\/strong\u003e Confirm that the installed base unit belongs to a supported family and accepts the required module configuration.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck the slot plan:\u003c\/strong\u003e Follow the system hardware documentation for module placement, especially in redundant configurations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInspect segment wiring:\u003c\/strong\u003e Confirm terminal connections, cable routing, polarity requirements, and approved segment wiring practices.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReview termination:\u003c\/strong\u003e Check the switchable built-in terminators against the approved segment topology. Avoid incorrect or duplicate termination.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCount devices:\u003c\/strong\u003e Include the ALF111 in the maximum 32-unit segment count and separately verify the 48-point control I\/O limit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck power capacity:\u003c\/strong\u003e Allow for the specified module current consumption and the total load of the node.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eValidate communications:\u003c\/strong\u003e Confirm that the control system recognizes the module and that expected field devices communicate successfully.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest redundancy:\u003c\/strong\u003e Where redundancy is configured, verify module status and changeover behavior using the approved system procedure.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eAlways isolate equipment and follow site safety procedures before changing wiring or module connections. Use the applicable Yokogawa installation and maintenance documentation for detailed procedures.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e6. Communication Diagnostics and Troubleshooting\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eObserved Symptom\u003c\/th\u003e\n\u003cth\u003eChecks to Perform\u003c\/th\u003e\n\u003cth\u003eEngineering Consideration\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eField devices fail to communicate\u003c\/td\u003e\n\u003ctd\u003eInspect segment wiring, termination, device power, and device configuration.\u003c\/td\u003e\n\u003ctd\u003eCheck the affected port and segment before replacing the module.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSeveral devices on one segment become unavailable\u003c\/td\u003e\n\u003ctd\u003eReview common wiring points, segment power, and termination settings.\u003c\/td\u003e\n\u003ctd\u003eA shared segment fault may affect multiple devices simultaneously.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDevice capacity exceeds the design limit\u003c\/td\u003e\n\u003ctd\u003eRecount all fieldbus units, including the ALF111.\u003c\/td\u003e\n\u003ctd\u003eDo not exceed 32 units per segment.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl scanning performance does not meet expectations\u003c\/td\u003e\n\u003ctd\u003eReview the configured I\/O points and scanning-cycle assignments.\u003c\/td\u003e\n\u003ctd\u003eHigh-speed scanning allocation has specific configuration conditions.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRedundant operation does not behave as expected\u003c\/td\u003e\n\u003ctd\u003eCheck module placement, redundancy configuration, and system status indications.\u003c\/td\u003e\n\u003ctd\u003eConfirm the node supports the intended redundant arrangement.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule replacement does not restore communication\u003c\/td\u003e\n\u003ctd\u003eVerify the complete model code, hardware compatibility, configuration, and field wiring.\u003c\/td\u003e\n\u003ctd\u003eA replacement module cannot correct an unrelated segment or configuration fault.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003e\u003cstrong\u003eDiagnostic capability note:\u003c\/strong\u003e The supplied specifications identify LAS and clock master functions, but do not define a complete onboard diagnostic feature set. Use the host control system's available status information and approved troubleshooting tools. Do not assume specific fault codes, event logs, or diagnostic LEDs without checking the relevant manual.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e7. Electrical Isolation and Connection Details\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eItem\u003c\/th\u003e\n\u003cth\u003eSpecification or Requirement\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eField-to-system withstand voltage\u003c\/td\u003e\n\u003ctd\u003e1500 V AC for 1 minute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary-to-secondary withstand voltage\u003c\/td\u003e\n\u003ctd\u003e1500 V AC for 1 minute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChannel-to-channel withstand voltage\u003c\/td\u003e\n\u003ctd\u003e1500 V AC for 1 minute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExternal bus connection\u003c\/td\u003e\n\u003ctd\u003eRemovable pressure-clamp terminal block\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTermination arrangement\u003c\/td\u003e\n\u003ctd\u003eBuilt-in terminators with on\/off switching\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTerminal board connection\u003c\/td\u003e\n\u003ctd\u003eDedicated cable connection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003eWithstand-voltage ratings describe specified insulation test performance. They do not replace grounding, isolation, wiring, or hazardous-area installation requirements.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e8. Global PLC Spare HUB's Insight\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eFor the ALF111-S50, the main selection risk is often segment design rather than the nominal communication speed. Engineers should validate the device count, control I\/O allocation, termination, and node compatibility together.\u003c\/p\u003e\n\n\u003cp\u003eThe four-port architecture can simplify fieldbus distribution across separate instrument groups. However, each port represents one segment, so capacity must be checked individually rather than combined across the module.\u003c\/p\u003e\n\n\u003cp\u003eFor redundancy projects, confirm the exact adjacent-slot arrangement and host-system support before procurement. A redundant hardware arrangement alone does not prove that the entire communication path has redundant power, wiring, or field devices.\u003c\/p\u003e\n\n\u003cp\u003eDuring fault investigation, begin with the affected segment and shared connection points. This approach helps distinguish wiring or termination issues from module, node, and configuration problems.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003e9. Supply, Warranty, and Shipping\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct:\u003c\/strong\u003e Yokogawa ALF111-S50 FOUNDATION Fieldbus Communication Module.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e Confirm the supplied condition and packaging details with the sales team before ordering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 12-month seller warranty, subject to the agreed sales terms.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping options:\u003c\/strong\u003e FedEx, UPS, or DHL, subject to destination and service availability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDispatch:\u003c\/strong\u003e Typically within 24–48 hours after order confirmation, subject to stock availability and payment verification.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage contents:\u003c\/strong\u003e The module is supplied according to the confirmed order configuration. Additional cables, terminal boards, and accessories are not assumed to be included.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003e10. Frequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ1. How can I confirm whether the ALF111-S50 will fit an existing Yokogawa node?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eCheck the node model, base-unit variant, available slot, and system hardware revision. Compare them with the official compatibility documentation before ordering.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ2. Can all four ports share one combined limit of 32 fieldbus devices?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The specification states a maximum of 32 units per segment, including the ALF111 as one unit. Calculate the device count separately for each port's segment.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ3. What information should I provide when requesting a replacement quote?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eProvide the full ALF111-S50 code, a clear label photograph, the host node model, and the required quantity. Include the existing module's installation position when available.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ4. Does the ALF111-S50 guarantee uninterrupted communication during a module failure?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo module specification alone guarantees uninterrupted service. The ALF111 supports a dual-redundancy configuration, but actual continuity depends on system design, configuration, field wiring, and validated changeover behavior.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ5. What should I check before commissioning a newly installed module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eVerify slot compatibility, segment termination, device counts, node power capacity, and host-system recognition. Then test each segment and any configured redundancy under the site's approved commissioning procedure.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRequest a Quote for ALF111-S50\u003c\/strong\u003e\u003c\/h3\u003e\n\n\u003cp\u003eContact Global PLC Spare HUB to confirm availability, lead time, shipping options, and compatibility for your Yokogawa system. Provide your full model code and application details to help our team assess your requirements.\u003c\/p\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":67709090726070,"sku":"ALF111-S50","price":196.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0722\/7863\/8774\/files\/ALF111-S50.jpg?v=1792571267","url":"https:\/\/www.plcsparehub.com\/products\/alf111-s50-yokogawa-alf111-series-fieldbus-communication-module","provider":"Global PLC Spare Hub","version":"1.0","type":"link"}