{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7312-5BF04-0AB0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7312-5BF04-0AB0","canonicalUrl":"https://aoctrl.com/siemens/6ES7312-5BF04-0AB0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7312-5BF04-0AB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens S7-300 CPU 312C, compact CPU with integrated digital I/O, 64 inputs and 64 outputs, 8 function blocks (FM 8), 80 x 125 x 130 mm.","salesMarkdown":"## CPU 312C with 8 integrated function blocks The Siemens 6ES7312-5BF04-0AB0 is a CPU 312C for the S7-300 rack, packing 64 digital inputs and 64 digital outputs directly on the CPU — enough for a compact machine cell without a separate I/O rack. The FM 8 rating means it executes up to 8 function blocks (SFB type) in the firmware, which handles high-speed counting, frequency measurement, and pulse-width modulation without loading the user program scan. ## Memory, programming, and network fit Program memory is 256 bytes maximum for the command set (see instruction list for the full assembly). It programs in LAD, FBD, STL, SCL, GRAPH, and HiGraph via STEP 7 V5.5 + SP1 or higher (or V5.3 + SP2 with HSP 203). The CPU has one MPI port (RS 485) for programming and simple networking; PROFIBUS DP requires an external CP module (up to 4 CPs, 4 LAN CPs, 8 PtP CPs). PROFINET and PROFIsafe are not native — add a CP for Ethernet connectivity. ## Panel fit and operating limits The CPU measures 80 mm wide, 125 mm high, and 130 mm deep — it occupies one slot on the S7-300 DIN rail and leaves room for up to 8 additional modules in the rack (overall 6 modules maximum per the spec). Operating temperature range is 0 °C to 60 °C, so it sits in a ventilated enclosure without forced cooling for most factory-floor environments. The I2t rating of 0.7 A²·s is the thermal energy the internal 24 VDC supply can handle during a short-circuit event — relevant when sizing the external circuit protection. No lifecycle status or successor is listed for this CPU 312C variant.","metaTitle":"Siemens 6ES7312-5BF04-0AB0 CPU 312C, FM 8, 64 I/O","metaDescription":"Siemens 6ES7312-5BF04-0AB0 CPU 312C with 8 integrated function blocks, 64 digital inputs and 64 outputs. Sourced to order against RFQ. Request a quote.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["PLCs (Programmable Logic Controllers)"],"specifications":{"FM":"8","FBD":"Yes","I2t":"0.7 A²·s","LAD":"Yes","MPI":"Yes","SCL":"Yes","STL":"Yes","Max.":"60 °C","Min.":"0 °C","Type":"SFB","Depth":"130 mm","GRAPH":"Yes","Width":"80 mm","Height":"125 mm","Inputs":"64","Number":"1","Preset":"10","RS 485":"Yes","STEP 7":"Yes; STEP 7 V5.5 + SP1 or higher or STEP 7 V5.3 + SP2 or higher with HSP 203","via CP":"4","CP, LAN":"4","CP, PtP":"8","Forcing":"Yes","Outputs":"64","Overall":"6","Present":"Yes","Routing":"No","Isolated":"No","As Client":"Yes; Via CP and loadable FB","As Server":"Yes","HiGraph®":"Yes","PROFIsafe":"No","Retentive":"Yes; Must be restarted at each restart","Supported":"Yes; via CP and loadable FC","Variables":"Inputs, outputs, memory bits, DB, times, counters","Adjustable":"Yes; From 10 to 499","Expandable":"No","Size, max.":"256 byte","Command set":"see instruction list","Granularity":"1 h","Lower Limit":"48 Ω","Racks, max.":"1","Rated value":"3 ms","STEP 7 Lite":"No","Single step":"Yes","Upper Limit":"4 kΩ","For Uprating":"No","Number, max.":"see instruction list","Status block":"Yes; Up to 2 simultaneously","in AS, slave":"No","2-Wire Sensor":"Yes","Plug-in (MMC)":"Yes","in AS, master":"Yes","to MPI, slave":"Yes","Digital inputs":"124.0 to 125.1","For Signal \"0\"":"-3 to +5V","For Signal \"1\"":"+15 to +30 V","Interface type":"Integrated RS 485 interface","Nesting levels":"8","PID controller":"No","Shielded, Max.":"1 000 m","Software clock":"Yes","to MPI, master":"Yes","Can Be Read Out":"Yes","Digital outputs":"124.0 to 124.5","Inputs, default":"128 byte","Parameterizable":"Yes; 0.1 / 0.3 / 3 / 15 ms (You can reconfigure the input delay of the standard inputs during program runtime. Please note that under certain circumstances your newly set filter time may not be effective until the next filter cycle.)","Range of values":"0 to 2^31 hours (when using SFC 101)","Weight, approx.":"410 g","Without Battery":"Yes; Program and data","lifecycle_stage":"eol_hot","Block encryption":"Yes; With S7 block Privacy","Firmware version":"V3.3","Of Which Central":"64","Outputs, default":"128 byte","Power loss, typ.":"8 W","Rated value (DC)":"24 V","S7 communication":"Yes; Only server, configured on one side","Unshielded, Max.":"600 m","PROFIBUS DP slave":"No","Repeat rate, min.":"1 s","Forcing, variables":"Inputs, outputs","Inputs, adjustable":"1 024 byte","Number of counters":"2; See \"Technological Functions\" manual","On Lamp Load, Max.":"100 Hz","PROFIBUS DP master":"No","Per Priority Class":"16","Retentivity preset":"Yes","up to 40 °C, max.":"1.5 A","up to 60 °C, max.":"1.5 A","At \"0\" To \"1\", Max.":"48 µs; Minimum pulse width/minimum pause between pulses at maximum counting frequency","Data record routing":"No","Number/Number range":"0","Outputs, adjustable":"1 024 byte","PG/OP communication":"Yes","Plug-in (MMC), max.":"8 Mbyte","Programming package":"STEP 7 V5.5 + SP1 or higher or STEP 7 V5.3 + SP2 or higher with HSP 203","Between The Channels":"No","For Signal \"1\", Min.":"L+ (-0.8 V)","For Signal \"1\", Typ.":"8 mA","HW functional status":"01","Inrush current, typ.":"5 A","Frequency measurement":"Yes","Isolation tested with":"600 V DC","Number of breakpoints":"4","Number of startup OBs":"1; OB 100","Retentivity available":"Yes; MB 0 to MB 255","Controlled Positioning":"No","Modules per rack, max.":"8","Retentivity adjustable":"Yes; via non-retain property on DB","S7 basic communication":"Yes","System functions (SFC)":"see instruction list","Deviation per day, max.":"10 s; Typ.: 2 s","Limit frequency (pulse)":"2.5 kHz","Number of analog inputs":"0","Number of entries, max.":"500","Number of pulse outputs":"2; Pulse width modulation up to 2.5 kHz (see \"Technological Functions\" Manual)","Status/control variable":"Yes","Transmission rate, max.":"187.5 kbit/s","User data per job, max.":"180 byte; (with PUT/GET)","Counting frequency, max.":"10 kHz","For Bit Operations, Typ.":"0.1 µs","Number of GD loops, max.":"8","Number of analog outputs":"0","Number of blocks (total)":"1 024; (DBs, FCs, FBs); the maximum number of loadable blocks can be reduced by the MMC used.","Number of clock memories":"8; 1 memory byte","Number of digital inputs":"10","Number of free cycle OBs":"1; OB 1","Number of time alarm OBs":"1; OB 10","Of Which Powerfail-Proof":"100; Only the last 100 entries are retained","Per Priority Class, Max.":"32 kbyte; Max. 2048 bytes per block","Response threshold, typ.":"1 A","Short-circuit protection":"Yes; Clocked electronically","Size of GD packets, max.":"22 byte","integrated channels (AI)":"0","integrated channels (AO)":"0","integrated channels (DI)":"10","integrated channels (DO)":"6","For Word Operations, Typ.":"0.24 µs","Global data communication":"Yes","Number of delay alarm OBs":"2; OB 20, 21","Number of digital outputs":"6","Number of variables, max.":"10","Point-to-point connection":"No","With Inductive Load, Max.":"0.5 Hz","With Resistive Load, Max.":"100 Hz","For Signal \"1\" Rated Value":"500 mA","Number of GD packets, max.":"8","Number of frequency meters":"2; up to 10 kHz (see \"Technological Functions\" manual)","from load voltage L+, max.":"25 mA","Controlling a digital input":"Yes","Number of RS 422 interfaces":"0","Number of RS 485 interfaces":"1; MPI","Number of process alarm OBs":"1; OB 40","Of Which High-Speed Outputs":"2; Notice: You cannot connect the fast outputs of your CPU in parallel","Process diagnostic messages":"Yes","Reverse polarity protection":"No","S7 communication, as client":"No; but via CP and loadable FB","S7 communication, as server":"Yes","usable for OP communication":"5","usable for PG communication":"5","Retentive And Synchronizable":"No; Buffered: No, Can be synchronized: Yes","System function blocks (SFB)":"see instruction list","Number of PROFINET interfaces":"0","additional within an error OB":"4","reserved for OP communication":"1","reserved for PG communication":"1","Number of cyclic interrupt OBs":"4; OB 32, 33, 34, 35","For Redundant Control Of A Load":"Yes","Number of expansion units, max.":"0","Number of synchronous error OBs":"2; OB 121, 122","Of Which Status Variables, Max.":"30","For Fixed Point Arithmetic, Typ.":"0.32 µs","Number of asynchronous error OBs":"4; OB 80, 82, 85, 87","Of Which Control Variables, Max.":"14","Current consumption (rated value)":"570 mA","usable for S7 basic communication":"2","For Floating Point Arithmetic, Typ.":"1.1 µs","For Signal \"1\" Minimum Load Current":"5 mA","Potential separation digital inputs":"Yes","permissible range, lower limit (DC)":"19.2 V","permissible range, upper limit (DC)":"28.8 V","reserved for S7 basic communication":"0","Number of GD packets, receiver, max.":"8","Potential separation digital outputs":"Yes","For Signal \"0\" Residual Current, Max.":"0.5 mA","Output current of the interface, max.":"200 mA","adjustable for OP communication, max.":"5","adjustable for OP communication, min.":"1","adjustable for PG communication, max.":"5","adjustable for PG communication, min.":"1","Between The Channels And Backplane Bus":"Yes","For Signal \"1\" Permissible Range, Max.":"0.6 A","For Signal \"1\" Permissible Range, Min.":"5 mA","Status indicator digital input (green)":"Yes","Number of GD packets, transmitter, max.":"8","Number of entries readable in RUN, max.":"499","Status indicator digital output (green)":"Yes","Behavior of the clock following POWER-ON":"the clock continues at the time of day it had when power was switched off","Mains/voltage failure stored energy time":"5 ms","Number of industrial Ethernet interfaces":"0","simultaneously active Alarm-S blocks, max.":"300","Limitation of inductive shutdown voltage to":"L+ (-48 V)","User program protection/password protection":"Yes","adjustable for S7 basic communication, max.":"2","adjustable for S7 basic communication, min.":"0","Size of GD packet (of which consistent), max.":"22 byte","User data per job (of which consistent), max.":"240 byte; as server","Of The Pulse Outputs, With Resistive Load, Max.":"2.5 kHz","Current consumption (in no-load operation), typ.":"90 mA","Integrated Function Blocks (Closed-Loop Control)":"No","Of Which Inputs Usable For Technological Functions":"8","Permissible Quiescent Current (2-Wire Sensor), Max.":"1.5 mA","Number of login stations for message functions, max.":"6; Depending on the configured connections for PG/OP and S7 basic communication","Data management on MMC (after last programming), min.":"10 a","Retentive data area (incl. timers, counters, flags), max.":"64 kbyte","External Protection For Power Supply Lines (Recommendation)":"Miniature circuit breaker, type C; min. 2 A; miniature circuit breaker type B, min. 4 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$312.00","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/fa1d502ef63bdf9d68a2a4d5c8919fc5.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=124514&mlfb=6ES7312-5BF04-0AB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/6ES7312-5BF04-0AB0/alternatives.json"},"ai":{"faq":[{"question":"What is the memory size of 6ES7312-5BF04-0AB0?","answer":"The CPU 312C has a maximum program memory of 256 bytes for the command set (see the instruction list for the full assembly). Retentive data (inputs, outputs, memory bits, DBs, timers, counters) must be restarted at each restart."},{"question":"How can I order the Siemens 6ES7312-5BF04-0AB0 CPU 312C?","answer":"This CPU is sourced to order against an RFQ through independent distribution. Availability and pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7312-5BF04-0AB0","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/6ES7312-5BF04-0AB0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}