{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7321-7BH00-0AB0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7321-7BH00-0AB0","canonicalUrl":"https://aoctrl.com/siemens/6ES7321-7BH00-0AB0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7321-7BH00-0AB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-300 SM 321 digital input module, 6ES7321-7BH00-0AB0, 16 optically isolated inputs, 24 VDC, 20-pin front connector, with diagnostic alarm and hardware interrupt.","salesMarkdown":"## What this module does in an S7-300 rack The Siemens 6ES7321-7BH00-0AB0 is a SIMATIC S7-300 SM 321 digital input module that provides 16 optically isolated inputs at 24 VDC, with a 20-pin front connector for field wiring. It supports both diagnostic alarms and hardware interrupts, so the CPU can immediately flag an external fault or a change-of-state on any input without polling the module. ## Input characteristics and wiring The module accepts 2-wire proximity sensors with a permissible quiescent current up to 1.5 mA, and the input filter is parameterizable to 0.1 / 0.5 / 3 / 15 / 20 ms — choose the slower setting to debounce mechanical contacts or the faster one for high-speed sensor edges. Signal \"1\" is detected from 13 to 30 V (typical current draw 7 mA), while signal \"0\" is -30 to +5 V, giving a clean threshold at 24 VDC nominal with a permissible range of 20.4 to 28.8 V DC. All 16 inputs share a common group isolated from the backplane bus via optocouplers, tested at 500 V DC — no channel-to-channel isolation, so the field supply must be common across all inputs. The module snaps onto a DIN rail in the S7-300 rack, occupying one slot with a width of 40 mm, depth of 120 mm, and height of 125 mm. Power draw from the backplane bus is 55 mA at 5 V DC, plus up to 40 mA from the load voltage L+ (unloaded), with a typical power loss of 4 W.","metaTitle":"Siemens 6ES7321-7BH00-0AB0 SM 321 Digital Input Module","metaDescription":"Siemens 6ES7321-7BH00-0AB0 SIMATIC S7-300 SM 321 digital input module, 16 inputs, 24 VDC, diagnostic alarm, hardware interrupt.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Digital Input Modules"],"specifications":{"Depth":"120 mm","Width":"40 mm","Height":"125 mm","2-Wire Sensor":"Yes","For Signal \"0\"":"-30 to +5 V","For Signal \"1\"":"13 to 30V","Shielded, Max.":"1 000 m","Parameterizable":"Yes; 0.1 / 0.5 / 3 / 15 / 20 ms","Weight, approx.":"200 g","lifecycle_stage":"eol_hot","Diagnostic alarm":"Yes","Power loss, typ.":"4 W","Rated value (DC)":"24 V","Unshielded, Max.":"600 m","Hardware interrupt":"Yes","up to 40 °C, max.":"16","up to 60 °C, max.":"16","Diagnostics function":"Yes; internal/ external fault","For Signal \"1\", Typ.":"7 mA","Isolation tested with":"500 V DC","Number of digital inputs":"16","Required Front Connector":"20-pin","from backplane bus 5 V DC, max.":"55 mA","Between The Channels, In Groups Of":"16","permissible range, lower limit (DC)":"20.4 V","permissible range, upper limit (DC)":"28.8 V","Between The Channels And Backplane Bus":"Yes; Optocoupler","from load voltage L+ (without load), max.":"40 mA","Permissible Quiescent Current (2-Wire Sensor), Max.":"1.5 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$188.66","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=321062&mlfb=6ES7321-7BH00-0AB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/6ES7321-7BH00-0AB0/alternatives.json"},"ai":{"faq":[{"question":"Does 6ES7321-7BH00-0AB0 support diagnostic alarms and hardware interrupts?","answer":"Yes, the module supports both diagnostic alarms (internal/external fault) and hardware interrupts, allowing the CPU to react immediately to input events without cyclic polling."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7321-7BH00-0AB0","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/6ES7321-7BH00-0AB0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}