{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7521-1BL00-0AB0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7521-1BL00-0AB0","canonicalUrl":"https://aoctrl.com/siemens/6ES7521-1BL00-0AB0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7521-1BL00-0AB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-1500 digital input module, 6ES7521-1BL00-0AB0, 24 V DC P-reading, 32-bit counter, MSI, current lifecycle.","salesMarkdown":"## 24 V DC input module with integrated counter The Siemens 6ES7521-1BL00-0AB0 is a digital input module for the SIMATIC S7-1500 system, supporting 24 V DC P-reading inputs that can be used as a 32-bit counter. It also provides MSI (Motion Sensor Interface) capability, meaning it can directly connect to incremental encoders or proximity sensors that output A/B signals, reducing the need for a separate counting module. ## Signal thresholds and wiring length Signal '0' is detected from -30 to +5 V, signal '1' from +11 to +30 V with a typical input current of 2.5 mA at 24 V. Unshielded cable runs up to 600 m; shielded runs up to 1000 m, which covers most panel-to-field distances in a typical plant. The module supports wire-break detection for input currents below 350 µA, so a broken field wire is flagged as a diagnostic alarm rather than a false '0'.","metaTitle":"Siemens 6ES7521-1BL00-0AB0 Digital Input Module, 24 V DC","metaDescription":"Siemens 6ES7521-1BL00-0AB0 SIMATIC S7-1500 digital input module. 24 V DC, 32-bit counter, MSI support. Active production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Digital Input Modules"],"specifications":{"DI":"Yes","MSI":"Yes","Depth":"129 mm","Width":"35 mm","title":"6ES7521-1BL00-0AB0","Height":"147 mm","Counter":"Yes","RUN LED":"Yes; green LED","I&M data":"Yes; I&M0 to I&M3","ERROR LED":"Yes; red LED","Wire-break":"Yes; to I < 350 µA","description":"SIMATIC S7-1500, digital input module DI 32x24 V DC HF, 32 channels in groups of 16; of which 2 inputs as counters can be used; input delay 0.05..20 ms input type 3 (IEC 61131); diagnostics; hardware interrupts: front connector (screw terminals or push-in) to be ordered separately","Number, max.":"2","Oversampling":"No","2-Wire Sensor":"Yes","Short-circuit":"No","Counting width":"32 bit","For Signal \"0\"":"-30 to +5 V","For Signal \"1\"":"+11 to +30V","Shielded, Max.":"1 000 m","Gate start/stop":"Yes","Parameterizable":"Yes","Weight, approx.":"260 g","lifecycle_stage":"current","Diagnostic alarm":"Yes","Firmware version":"V2.2.1","Isochronous mode":"Yes","Power loss, typ.":"4.2 W","Rated value (DC)":"24 V","Unshielded, Max.":"600 m","Source/sink input":"P-reading","FW update possible":"Yes","Hardware interrupt":"Yes","At \"0\" To \"1\", Max.":"20 ms","At \"0\" To \"1\", Min.":"0.05 ms","At \"1\" To \"0\", Max.":"20 ms","At \"1\" To \"0\", Min.":"0.05 ms","Prioritized startup":"Yes","Between The Channels":"Yes","Diagnostics function":"Yes","For Signal \"1\", Typ.":"2.5 mA","HW functional status":"from FS04","Isolation tested with":"707 V DC (type test)","Channel status display":"Yes; green LED","For Module Diagnostics":"Yes; red LED","For Channel Diagnostics":"Yes; red LED","Counting frequency, max.":"6 kHz; FS04 and FW V2.2.1 or higher","Number of digital inputs":"32","Current consumption, max.":"40 mA; 20 mA per group with 24 V DC supply","Bus cycle time (TDP), min.":"250 µs","Counting direction up/down":"Up","Freely usable digital input":"Yes","Reverse polarity protection":"Yes","Vertical Installation, Max.":"40 °C","Vertical Installation, Min.":"-30 °C; From FS05","Horizontal Installation, Max.":"60 °C","Horizontal Installation, Min.":"-30 °C; From FS05","Monitoring the supply voltage":"Yes","Suitable for safety functions":"No","Digital inputs, parameterizable":"Yes","Between The Channels, In Groups Of":"16","permissible range, lower limit (DC)":"19.2 V","permissible range, upper limit (DC)":"28.8 V","Between The Channels And Backplane Bus":"Yes","PROFIBUS from GSD version/GSD revision":"V1.0 / V5.1","PROFINET from GSD version/GSD revision":"V2.3 / -","Power available from the backplane bus":"1.1 W","Filtering and processing time (TCI), min.":"80 µs; At 50 μs filter time","Monitoring of the supply voltage (PWR-LED)":"Yes; green LED","Installation altitude above sea level, max.":"5 000 m; Restrictions for installation altitudes > 2 000 m, see manual","STEP 7 configurable/integrated from version":"V5.5 SP3 / -","Permissible Quiescent Current (2-Wire Sensor), Max.":"1.5 mA","STEP 7 TIA Portal configurable/integrated from version":"V13 SP1 / -","Between The Channels And The Power Supply Of The Electronics":"No"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$211.11","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/32d5ce02789c6ce1878fb5198ca7caa3.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=537079&mlfb=6ES7521-1BL00-0AB0"},"ai":{"faq":[{"question":"Can 6ES7521-1BL00-0AB0 be used as a counter?","answer":"Yes. The module has a 32-bit counter function that can be parameterized, with gate start/stop and isochronous mode support."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7521-1BL00-0AB0","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/6ES7521-1BL00-0AB0 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}}