{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7421-1FH20-0AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7421-1FH20-0AA0","canonicalUrl":"https://aoctrl.com/siemens/6ES7421-1FH20-0AA0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7421-1FH20-0AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens 6ES7421-1FH20-0AA0 — now in phase-out and being discontinued, supplied from remaining surplus and broker stock.","salesMarkdown":"## Overview The 6ES7421-1FH20-0AA0 is a Siemens SM 421 digital input module for the S7-400 rack, providing 16 isolated inputs that accept UC 120/230 V (47...63 Hz) and comply with IEC 1131-2 Type 2. It draws 12.0 W from the backplane and fits a 25 mm wide slot, with a signal threshold of 74 to 264 V AC or 80 to 264 V DC for the 1-signal. Remaining units are available through surplus and broker channels.","metaTitle":"Siemens 6ES7421-1FH20-0AA0 SM 421 digital input module, 16 DI, UC 120/230 V","metaDescription":"Siemens 6ES7421-1FH20-0AA0 SM 421 digital input module: 16 isolated inputs, UC 120/230 V, 12.0 W, for S7-400. Phased out since 2025-10-01.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"NRND","categoryPath":["Digital Input Modules"],"specifications":{"Depth":"210 mm","Width":"25 mm","Height":"290 mm","2-Wire Sensor":"Yes","For Signal \"0\"":"0 to 40 V AC/ -40 to +40 V DC","For Signal \"1\"":"74 to 264 V AC; 80 to 264 V DC, -80 to -264 V","Shielded, Max.":"1 000 m","Weight, approx.":"650 g","lifecycle_stage":"mature","Power loss, typ.":"12 W","Rated value (UC)":"230 V; 120/230 V UC (47 ... 63 Hz)","Unshielded, Max.":"600 m","At \"0\" To \"1\", Max.":"20 ms; AC: 20 ms; DC: 15 ms","At \"1\" To \"0\", Max.":"30 ms; AC: 30 ms; DC: 25 ms","Between The Channels":"Yes","Diagnostics function":"No","For Signal \"0\", Min.":"0 mA; AC: 0 mA; DC: 0 mA","For Signal \"1\", Typ.":"10 mA; at 120 V: 10 mA AC, 1.8 mA DC; at 230 V: 14 mA AC, 2 mA DC","Isolation tested with":"1 500 V AC","Type of input voltage":"AC/DC","Number of digital inputs":"16","from backplane bus 5 V DC, max.":"80 mA","Between The Channels, In Groups Of":"4","Between The Channels And Backplane Bus":"Yes","Status indicator digital input (green)":"Yes","Input characteristic according to IEC 61131":"Type 2","Number of simultaneously controllable inputs":"16","Permissible Quiescent Current (2-Wire Sensor), Max.":"5 mA; AC: 5 mA","For Signal \"0\", Max. (Permissible Quiescent Current)":"6 mA; AC: 6 mA; DC: 2 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$243.71 – $601.00","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/b17e04f809dbd939261743a291734bbd.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=304351&mlfb=6ES7421-1FH20-0AA0"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7421-1FH20-0AA0","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/6ES7421-1FH20-0AA0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-06-29T07:19:29.075Z","lastPublished":"2026-06-29T07:19:29.075Z","indexable":true}}