{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7521-1BH00-0AB0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7521-1BH00-0AB0","canonicalUrl":"https://aoctrl.com/siemens/6ES7521-1BH00-0AB0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7521-1BH00-0AB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens S7-1500 digital input module, 6ES7521-1BH00-0AB0, 24 VDC, with 32-bit counter, diagnostics, isochronous mode, and I&M data.","salesMarkdown":"The Siemens 6ES7521-1BH00-0AB0 is a 24 VDC digital input module for the S7-1500 system, equipped with a 32-bit counter, gate start/stop, and diagnostic functions. Signal thresholds are -30 to +5 V for a '0' and +11 to +30 V for a '1', with a typical input current of 2.5 mA at signal '1'. Response times range from 0.05 ms to 20 ms depending on the transition direction. ## Mounting and wiring note Sized at 35 mm width, 129 mm depth, and 147 mm height; shielded cable reach is 1 000 m, unshielded 600 m. Wire-break detection triggers below 350 µA, and isochronous mode enables synchronized sampling. ## Field service — fault isolation Diagnostic alarms and hardware interrupts are available, signaled through a red ERROR LED and a green RUN LED. The firmware version is V2.2.0 and is field-upgradable. Module-specific interrupt (MSI) is supported, which can be mapped to the I&M data (I&M0 to I&M3) for asset tracking in large installations. The counting function uses a 32-bit width and can be parameterized online via prioritized startup.","metaTitle":"Siemens 6ES7521-1BH00-0AB0 Digital Input Module, 24 VDC, 32-","metaDescription":"Siemens 6ES7521-1BH00-0AB0 S7-1500 DI module, 24 VDC, 16-channel? Digital inputs with 32-bit counter, diagnostic alarm, and isochronous mode. Currently in active production. Source","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":"6ES7521-1BH00-0AB0","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 16x24 V DC HF, 16 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.":"240 g","lifecycle_stage":"current","Diagnostic alarm":"Yes","Firmware version":"V2.2.0","Isochronous mode":"Yes","Power loss, typ.":"2.6 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":"No","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","Number of digital inputs":"16","Current consumption, max.":"20 mA; 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":"$144.78","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/6a73f13e58645ca1c29fdd252445b2fa.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=521666&mlfb=6ES7521-1BH00-0AB0"},"ai":{"faq":[{"question":"Can the 6ES7521-1BH00-0AB0 replace a 6ES7522-1BH01-0AB0 in a panel?","answer":"No. The 6ES7522-1BH01-0AB0 is a digital output module, while the 6ES7521-1BH00-0AB0 is a digital input module. They are not functionally equivalent and cannot be swapped without changing wiring, configuration, and possibly the power supply."},{"question":"What does the 'DI' and 'MSI' ratings mean?","answer":"DI means digital input module (Yes, it accepts discrete field signals). MSI stands for module-specific interrupt (Yes, it supports hardware interrupts for event-driven processing)."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7521-1BH00-0AB0","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/6ES7521-1BH00-0AB0 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}}