{"id":32851,"date":"2026-01-14T15:50:34","date_gmt":"2026-01-14T15:50:34","guid":{"rendered":"https:\/\/c2psu.com\/?post_type=product&p=32851"},"modified":"2026-03-01T12:30:59","modified_gmt":"2026-03-01T12:30:59","slug":"siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0","status":"publish","type":"product","link":"https:\/\/www.c2psu.com\/ms\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/","title":{"rendered":"Siemens Digital Input SM 421, Potential Isolation 16 DE 6ES7421-1FH20-0AA0 Original"},"content":{"rendered":"
<\/div>\n

\"gGqRi\/mnzdQy998gxNFqwsR4RnO9VEvOkkIE\"
Order number:6ES7421-1FH20-0AA0<\/span><\/span><\/p>\n

Origin: Germany
\nItem number: 6ES7421-1FH20-0AA0
\nBrand: SIEMENS\/Siemens
\nModel: 6ES7421-1FH20-0AA0
\nWorking voltage: 24
\nOutput frequency: 24
\nProduct Certification: Ce
\nWhether Cross-Border Export Is Exclusively Available: No
\nSeries:S7-400
\nMaterial code: 7675625852<\/p>\n

\n
\n
\n
\n
\n
<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
\n
<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation<\/strong>\u00a0. It provides\u00a016 digital inputs<\/strong>\u00a0with a nominal voltage of 120V AC or 230V AC (47-63 Hz), featuring input delay of approximately 25 ms for standard AC applications . The inputs feature\u00a0individual isolation per channel<\/strong>\u00a0(groups of 1), providing excellent noise immunity and flexibility for mixed-voltage wiring . Backplane bus current consumption is 25 mA . The module includes front connector wiring (screw-type terminals sold separately) . Suitable for use in S7-400 racks, it has a\u00a0discontinued lifecycle status (PM410)<\/strong>\u00a0and is intended as a spare part for legacy systems with AC field device requirements .<\/p>\n

\n
<\/div>\n<\/div>","protected":false},"featured_media":39767,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_elementor_edit_mode":"","_elementor_template_type":"","_elementor_data":"","_elementor_page_settings":null,"_elementor_conditions":[]},"etheme_brands":[{"term_id":5558,"name":"SIEMENS","slug":"siemens","term_group":0,"term_taxonomy_id":5558,"taxonomy":"brand","description":"Siemens AG is a\u00a0German multinational technology conglomerate<\/strong>\u00a0headquartered in Munich, Germany. As a global powerhouse in industrial manufacturing and technology, it operates across the digital industrial, smart infrastructure, mobility, and healthcare sectors.\r\n\r\nAt Siemens, our purpose is to create technology to transform the everyday, for everyone. We are a leading technology company focused on industry, infrastructure, transport, and healthcare, driven by the belief that sustainability is good business and serves as a powerful force for good.\r\n
\r\n
<\/div>\r\n<\/div>","parent":0,"count":100,"filter":"raw"}],"product_brand":[610],"product_cat":[605],"product_tag":[3601,3602,2947,526,3577,804,3578,3479],"class_list":{"0":"post-32851","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"brand-siemens","7":"product_brand-siemens","8":"product_cat-programmable-logic-controllers-plcs","9":"product_tag-3601","10":"product_tag-6es7421-1fh20-0aa0","11":"product_tag-digital","12":"product_tag-input","13":"product_tag-isolation","14":"product_tag-original","15":"product_tag-potential","16":"product_tag-siemens-5","17":"pa_option-6es7421-1fh20-0aa0-2","19":"first","20":"instock","21":"sale","22":"purchasable","23":"product-type-simple"},"acf":[],"yoast_head":"\nSiemens SM 421, 16 DE 6ES7421-1FH20-0AA0<\/title>\n<meta name=\"description\" content=\"The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation\u00a0.\u00a0\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.c2psu.com\/ms\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/\" \/>\n<meta property=\"og:locale\" content=\"ms_MY\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Siemens Digital Input SM 421, Potential Isolation 16 DE 6ES7421-1FH20-0AA0 Original\" \/>\n<meta property=\"og:description\" content=\"The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation\u00a0.\u00a0\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.c2psu.com\/ms\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/\" \/>\n<meta property=\"og:site_name\" content=\"C2PSU\" \/>\n<meta property=\"article:modified_time\" content=\"2026-03-01T12:30:59+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png\" \/>\n\t<meta property=\"og:image:width\" content=\"800\" \/>\n\t<meta property=\"og:image:height\" content=\"800\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Price\" \/>\n\t<meta name=\"twitter:data1\" content=\"$402.10\" \/>\n\t<meta name=\"twitter:label2\" content=\"Availability\" \/>\n\t<meta name=\"twitter:data2\" content=\"In stock\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/\",\"url\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/\",\"name\":\"Siemens SM 421, 16 DE 6ES7421-1FH20-0AA0\",\"isPartOf\":{\"@id\":\"https:\/\/www.c2psu.com\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png\",\"datePublished\":\"2026-01-14T15:50:34+00:00\",\"dateModified\":\"2026-03-01T12:30:59+00:00\",\"description\":\"The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation\u00a0.\u00a0\",\"breadcrumb\":{\"@id\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#breadcrumb\"},\"inLanguage\":\"ms-MY\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"ms-MY\",\"@id\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#primaryimage\",\"url\":\"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png\",\"contentUrl\":\"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png\",\"width\":800,\"height\":800},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.c2psu.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Shop\",\"item\":\"https:\/\/www.c2psu.com\/products\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Siemens Digital Input SM 421, Potential Isolation 16 DE 6ES7421-1FH20-0AA0 Original\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.c2psu.com\/#website\",\"url\":\"https:\/\/www.c2psu.com\/\",\"name\":\"C2PSU\",\"description\":\"Industrial electronics\",\"publisher\":{\"@id\":\"https:\/\/www.c2psu.com\/#organization\"},\"alternateName\":\"C2PSU-Industrial electronics\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.c2psu.com\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"ms-MY\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.c2psu.com\/#organization\",\"name\":\"C2PSU\",\"url\":\"https:\/\/www.c2psu.com\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"ms-MY\",\"@id\":\"https:\/\/www.c2psu.com\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.c2psu.com\/wp-content\/uploads\/2025\/11\/C2PSU.png\",\"contentUrl\":\"https:\/\/www.c2psu.com\/wp-content\/uploads\/2025\/11\/C2PSU.png\",\"width\":755,\"height\":374,\"caption\":\"C2PSU\"},\"image\":{\"@id\":\"https:\/\/www.c2psu.com\/#\/schema\/logo\/image\/\"},\"hasMerchantReturnPolicy\":{\"@type\":\"MerchantReturnPolicy\",\"merchantReturnLink\":\"https:\/\/www.c2psu.com\/ms\/refund_returns\/\"}}]}<\/script>\n<meta property=\"product:price:amount\" content=\"402.10\" \/>\n<meta property=\"product:price:currency\" content=\"USD\" \/>\n<meta property=\"og:availability\" content=\"instock\" \/>\n<meta property=\"product:availability\" content=\"instock\" \/>\n<meta property=\"product:retailer_item_id\" content=\"778305750048_6ES7421-1FH20-0AA0\" \/>\n<meta property=\"product:condition\" content=\"new\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Siemens SM 421, 16 DE 6ES7421-1FH20-0AA0","description":"The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation\u00a0.\u00a0","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.c2psu.com\/ms\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/","og_locale":"ms_MY","og_type":"article","og_title":"Siemens Digital Input SM 421, Potential Isolation 16 DE 6ES7421-1FH20-0AA0 Original","og_description":"The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation\u00a0.\u00a0","og_url":"https:\/\/www.c2psu.com\/ms\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/","og_site_name":"C2PSU","article_modified_time":"2026-03-01T12:30:59+00:00","og_image":[{"width":800,"height":800,"url":"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png","type":"image\/png"}],"twitter_card":"summary_large_image","twitter_misc":{"Price":"$402.10","Availability":"In stock"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/","url":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/","name":"Siemens SM 421, 16 DE 6ES7421-1FH20-0AA0","isPartOf":{"@id":"https:\/\/www.c2psu.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#primaryimage"},"image":{"@id":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#primaryimage"},"thumbnailUrl":"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png","datePublished":"2026-01-14T15:50:34+00:00","dateModified":"2026-03-01T12:30:59+00:00","description":"The Siemens 6ES7421-1FH20-0AA0 (SM 421) is a digital input module for the SIMATIC S7-400 PLC family, designed for\u00a0120\/230V AC operation\u00a0.\u00a0","breadcrumb":{"@id":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#breadcrumb"},"inLanguage":"ms-MY","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/"]}]},{"@type":"ImageObject","inLanguage":"ms-MY","@id":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#primaryimage","url":"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png","contentUrl":"https:\/\/www.c2psu.com\/wp-content\/uploads\/6ES7421-1FH20-0AA0.png","width":800,"height":800},{"@type":"BreadcrumbList","@id":"https:\/\/www.c2psu.com\/product\/siemens-sm-421-potential-isolation-16-de-6es7421-1fh20-0aa0\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.c2psu.com\/"},{"@type":"ListItem","position":2,"name":"Shop","item":"https:\/\/www.c2psu.com\/products\/"},{"@type":"ListItem","position":3,"name":"Siemens Digital Input SM 421, Potential Isolation 16 DE 6ES7421-1FH20-0AA0 Original"}]},{"@type":"WebSite","@id":"https:\/\/www.c2psu.com\/#website","url":"https:\/\/www.c2psu.com\/","name":"C2PSU","description":"Industrial electronics","publisher":{"@id":"https:\/\/www.c2psu.com\/#organization"},"alternateName":"C2PSU-Industrial electronics","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.c2psu.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"ms-MY"},{"@type":"Organization","@id":"https:\/\/www.c2psu.com\/#organization","name":"C2PSU","url":"https:\/\/www.c2psu.com\/","logo":{"@type":"ImageObject","inLanguage":"ms-MY","@id":"https:\/\/www.c2psu.com\/#\/schema\/logo\/image\/","url":"https:\/\/www.c2psu.com\/wp-content\/uploads\/2025\/11\/C2PSU.png","contentUrl":"https:\/\/www.c2psu.com\/wp-content\/uploads\/2025\/11\/C2PSU.png","width":755,"height":374,"caption":"C2PSU"},"image":{"@id":"https:\/\/www.c2psu.com\/#\/schema\/logo\/image\/"},"hasMerchantReturnPolicy":{"@type":"MerchantReturnPolicy","merchantReturnLink":"https:\/\/www.c2psu.com\/ms\/refund_returns\/"}}]},"product_price_amount":"402.10","product_price_currency":"USD","og_availability":"instock","product_availability":"instock","product_retailer_item_id":"778305750048_6ES7421-1FH20-0AA0","product_condition":"new"},"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product\/32851","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/comments?post=32851"}],"version-history":[{"count":2,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product\/32851\/revisions"}],"predecessor-version":[{"id":40646,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product\/32851\/revisions\/40646"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/media\/39767"}],"wp:attachment":[{"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/media?parent=32851"}],"wp:term":[{"taxonomy":"brand","embeddable":true,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/etheme_brands?post=32851"},{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product_brand?post=32851"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product_cat?post=32851"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.c2psu.com\/ms\/wp-json\/wp\/v2\/product_tag?post=32851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}