{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7921-4BC50-0AA1","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7921-4BC50-0AA1","canonicalUrl":"https://aoctrl.com/siemens/6ES7921-4BC50-0AA1","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7921-4BC50-0AA1","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-400, pre-assembled front connector, 6ES7921-4BC50-0AA1, 48-pole, 2.5 m cable, 60 V rated, 1 A per contact.","salesMarkdown":"The Siemens 6ES7921-4BC50-0AA1 is a pre-assembled front connector for SIMATIC S7-400 digital I/O modules. It comes with four round cables, each 2.5 m long, terminated with screw-type terminals on the field side. The 48-pole connector mates directly to the S7-400 front interface, so no field wiring to the module itself is needed — you land your field wires on the screw terminals, then plug the assembly onto the module. Rated at 60 V DC and 1 A per contact, with a total current limit of 4 A across all 48 poles. That 1 A per contact is the continuous current each signal path can carry — fine for 24 V DC digital inputs and outputs typical in S7-400 racks. The 4 A total means you cannot load all 48 contacts at 1 A simultaneously; the aggregate is the limit. ## Installation note Mounts directly onto the S7-400 module — no DIN rail or additional bracket. The cable exits at the top, so plan for overhead clearance in the cabinet. The 2.5 m cable length is the distance from the connector body to the terminal module; it is fixed, not field-cuttable. Screw-type terminals accept 0.14 mm² round cable as supplied; field wiring should use ferruled stranded conductors matching the terminal block specs.","metaTitle":"Siemens 6ES7921-4BC50-0AA1 S7-400 Front Connector, 2.5 m, 48","metaDescription":"Pre-assembled front connector for SIMATIC S7-400 digital I/O modules. 48 poles, 2.5 m cable, 60 V rated, 1 A per contact, 4 A total. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["PLC Accessories"],"specifications":{"title":"6ES7921-4BC50-0AA1","Length":"2.5 m","Rated Value":"60 V","description":"Front connector S7-400 for digital Pre-assembled with 4 round Cables 0.14 mm2, L = 2.5 m for digital connection modules","Mounting Type":"direct mounting","Target System":"SIMATIC S7-400","During Storage":"-30 ... +70 °C","Number Of Poles":"48; of the front connector","at DC / maximum":"30 V","lifecycle_stage":"mature","During Operation":"0 ... 60 °C","Degree Of Pollution":"2","Product Designation":"Pre-assembled front connector","Suitability For Use":"Digital I/O modules","at DC / rated value":"24 V","Overvoltage Category":"2","Current / Rated Value":"1 A","Operating Temperature":"0 ... 60 °C","Wire Length / Maximum":"2.5 m; between front connector module and terminal module","Total Current / Maximum":"4 A","Color / Of The Enclosure":"black","Position / Of The Terminal":"at the top","Product Feature / Transparent":"No","Material / Of The Insulating Body":"other","Number Of Poles / At The 1st Interface":"Cable is directly connected","reference code / according to IEC 81346-2":"WG","Product Component / Required / End Cover Plate":"No","design tested acc. to type of protection / EEx e":"No","Type Of Electrical Connection / For Connecting Cable":"Screw-type terminal"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$350.00","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/6d57f154fff616166253fab8c566f5cb.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=265410&mlfb=6ES7921-4BC50-0AA1"},"ai":{"faq":[{"question":"What is the cable length and rated voltage?","answer":"The cable length is 2.5 m and the rated voltage is 60 V DC. The connector is rated for 1 A per contact with a total current limit of 4 A."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7921-4BC50-0AA1","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/6ES7921-4BC50-0AA1 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}}