{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7321-1CH20-0AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7321-1CH20-0AA0","canonicalUrl":"https://aoctrl.com/siemens/6ES7321-1CH20-0AA0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7321-1CH20-0AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-300 SM 321, digital input module, 16 DI, isolated, 48-125 V DC, 20-pole front connector.","salesMarkdown":"This is the Siemens 6ES7321-1CH20-0AA0, a 16-point digital input module from the S7-300 SM 321 family, designed for 48-125 V DC control circuits. It accepts two-wire sensors and provides galvanic isolation in groups of 8 channels via optocouplers — a critical detail when wiring field devices that share a common potential on separate groups. Signal thresholds are clearly defined: a logic '0' spans -146 V to +15 V DC, while a logic '1' requires 30 V to 146 V DC (typical input current 3.5 mA). Switching times are in the sub‑millisecond range, with minimum rise/fall below 0.1 ms. ## Lifecycle reality — act now for spares There is no official Siemens replacement listed for this order code; any functional equivalent would need to accept 48-125 V DC and maintain the same 20-pin front connector. We source this module on a quoted-to-order basis — submit an RFQ and we will confirm availability and lead time from our surplus and redistribution network. ## Mechanical fit and wiring notes The module occupies a single S7-300 width: 40 mm wide, 125 mm high, 120 mm deep. It requires a 20-pin front connector (not included). Standard S7-300 rail mounting applies. Channels are in isolated groups of 8. Each group is optocoupler-isolated from the backplane bus. No diagnostic alarms, interrupts, or parameterization. Maximum cable lengths: 1 000 m shielded, 600 m unshielded. For two-wire sensors, the permissible quiescent current is limited to 1 mA.","metaTitle":"Siemens 6ES7321-1CH20-0AA0 SM 321 DI Module, 16 Inputs, 48-1","metaDescription":"16 digital inputs, 48-125 V DC, isolated, for S7-300. End-of-life phase. Sourced to order via RFQ. Act now for critical spares.","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":"6ES7321-1CH20-0AA0","Alarms":"No","Height":"125 mm","description":"SIMATIC S7-300, Digital input SM 321, isolated, 16 DI, 48-125 V DC, 1x 20-pole","2-Wire Sensor":"Yes","For Signal \"0\"":"-146 V DC to +15 V DC","For Signal \"1\"":"30 V DC to 146 V DC","Shielded, Max.":"1 000 m","Parameterizable":"No","Weight, approx.":"200 g","lifecycle_stage":"eol_hot","Diagnostic alarm":"No","Power loss, typ.":"4.3 W","Rated value (DC)":"48 V; 48 V DC to 125 V DC","Unshielded, Max.":"600 m","Hardware interrupt":"No","up to 40 °C, max.":"8","up to 60 °C, max.":"8; 6 to Ue 146 V","At \"0\" To \"1\", Max.":"3.5 ms","At \"0\" To \"1\", Min.":"0.1 ms","At \"1\" To \"0\", Max.":"3 ms","At \"1\" To \"0\", Min.":"0.7 ms","Between The Channels":"No","Diagnostics function":"No","For Signal \"1\", Typ.":"3.5 mA","Group error SF (red)":"No","Isolation tested with":"1 500 V DC","Type of input voltage":"DC","Number of digital inputs":"16","Required Front Connector":"20-pin","from backplane bus 5 V DC, max.":"40 mA","Between The Channels, In Groups Of":"8","permissible range, lower limit (DC)":"48 V","permissible range, upper limit (DC)":"125 V","Between The Channels And Backplane Bus":"Yes; Optocoupler","Status indicator digital input (green)":"Yes","Permissible Quiescent Current (2-Wire Sensor), Max.":"1 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$334.01 – $544.00","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/385ab7fcbbb51cd93671f2214eb70efc.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=440150&mlfb=6ES7321-1CH20-0AA0"},"ai":{"faq":[{"question":"What front connector does this module require?","answer":"It requires a 20-pin front connector. This is ordered separately."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7321-1CH20-0AA0","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/6ES7321-1CH20-0AA0 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}}