{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7321-1FF01-0AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7321-1FF01-0AA0","canonicalUrl":"https://aoctrl.com/siemens/6ES7321-1FF01-0AA0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7321-1FF01-0AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-300 SM 321 digital input module, 6ES7321-1FF01-0AA0, 8 isolated AC inputs, 120/230 V, 1x 20-pole front connector.","salesMarkdown":"## 8 AC inputs at 120/230 V — signal thresholds and isolation The 6ES7321-1FF01-0AA0 is an 8-channel digital input module for the SIMATIC S7-300 rack, accepting 120/230 V AC (47–63 Hz) on each channel. The signal-1 threshold is 79–264 V AC, drawing 6.5 mA typical at 120 V and 11 mA at 230 V; signal-0 is 0–40 V. That 79 V turn-on floor means it cleanly discriminates line-level AC signals from leakage or coupled noise on long runs — important when the unshielded cable length reaches 600 m. Channel-to-channel isolation is grouped in pairs (groups of 2), with optocoupler isolation between the input channels and the backplane bus. The isolation is tested at 4000 V DC, so the module handles mixed AC supplies on adjacent groups without coupling issues. ## Lifecycle status — end-of-life hot, sourcing reality The module draws 29 mA max from the 5 V DC backplane bus and dissipates 4.9 W typical power loss. It requires a 20-pin front connector (not included). The form factor is 40 mm wide, 125 mm high, 120 mm deep — standard S7-300 single-width slot. ## Integration notes — wiring, diagnostics, and 2-wire sensors The module accepts 2-wire proximity sensors, with a permissible quiescent current up to 2 mA — so standard AC proximity switches with a dark current below that threshold will not false-trigger the input. There is no parameterisable input filter; the switching delay is fixed at 25 ms for both 0→1 and 1→0 transitions, which is adequate for 50/60 Hz AC signals but means fast pulse trains (above ~20 Hz) will be missed. No diagnostic alarm, no hardware interrupt, no group error LED — the only status indication is a green LED per channel. The module is not isolated between channels (only between channel groups and the backplane).","metaTitle":"Siemens 6ES7321-1FF01-0AA0 SM 321, 8 DI 120/230 VAC","metaDescription":"Siemens 6ES7321-1FF01-0AA0 SIMATIC S7-300 SM 321 digital input module, 8 AC inputs 120/230 V, isolated, EOL hot. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Digital Input Modules"],"specifications":{"Depth":"120 mm","Width":"40 mm","title":"6ES7321-1FF01-0AA0","Alarms":"No","Height":"125 mm","description":"SIMATIC S7-300, Digital input SM 321, isolated, 8 DI, 120 V/230 V AC, 1x 20-pole","2-Wire Sensor":"Yes","For Signal \"0\"":"0 to 40V","For Signal \"1\"":"79 to 264V","Shielded, Max.":"1 000 m","Parameterizable":"No","Weight, approx.":"240 g","lifecycle_stage":"eol_hot","Diagnostic alarm":"No","Power loss, typ.":"4.9 W","Rated value (AC)":"230 V; 120/230 V AC (47 ... 63 Hz)","Unshielded, Max.":"600 m","Hardware interrupt":"No","up to 40 °C, max.":"8","up to 60 °C, max.":"8","At \"0\" To \"1\", Max.":"25 ms","At \"1\" To \"0\", Max.":"25 ms","Between The Channels":"No","Diagnostics function":"No","For Signal \"1\", Typ.":"6.5 mA; (120 V); 11 mA (230 V)","Group error SF (red)":"No","Isolation tested with":"4 000 V DC","Type of input voltage":"AC","Number of digital inputs":"8","Required Front Connector":"20-pin","from backplane bus 5 V DC, max.":"29 mA","Between The Channels, In Groups Of":"2","Between The Channels And Backplane Bus":"Yes; Optocoupler","Status indicator digital input (green)":"Yes","Permissible Quiescent Current (2-Wire Sensor), Max.":"2 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$107.95 – $238.00","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/324c1f0f7c8d66f0a900563be1b65d92.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=88487&mlfb=6ES7321-1FF01-0AA0"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7321-1FF01-0AA0","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/6ES7321-1FF01-0AA0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}