Siemens 6ES7512-1SK01-0AB0 — Discontinued CPU: Specs & Successor

By Abdullah Zahid
13 min read
Siemens 6ES7512-1SK01-0AB0 CPU 1512SP F-1 PN compact failsafe PLC for SIMATIC S7-1500F conveyor and safety control

Siemens 6ES7512-1SK01-0AB0 CPU 1512SP F-1 PN: Failsafe PLC Specifications, Pricing and Successor Guide

Controls engineers evaluating a compact, failsafe-capable PLC CPU for safety-critical machine control are typically choosing between over-specifying with a larger S7-1500F model or under-specifying with a standard non-failsafe CPU. The Siemens 6ES7512-1SK01-0AB0 — the CPU 1512SP F-1 PN within the SIMATIC S7-1500F family — resolves that tension with SIL 3 / PLe certification, an integrated 3-port PROFINET switch, PROFIBUS DP master capability, and 20 digital inputs and outputs built into a 100 × 117 × 75 mm module. One critical fact shapes every procurement decision here: this product was discontinued effective October 1, 2025, and its successor is the 6ES7512-1SM03-0AB0.

If you have already confirmed this is the right part for a spare parts order or an existing installation, check current pricing and availability at LeadTime.ca — we ship worldwide.

Who Should Buy the 6ES7512-1SK01-0AB0 — and Who Shouldn't

This CPU is the correct choice for engineers who need integrated failsafe logic, dual PROFINET and PROFIBUS connectivity, and a compact footprint in a single module — without purchasing a separate safety controller or external network switch.

  • Your application requires SIL 3 / PLe failsafe certification without a separate safety relay or external safety module
  • Your panel is space-constrained and the 100 × 117 × 75 mm form factor is a hard requirement
  • You need PROFINET IRT isochronous mode with a minimum 625 µs OB 6x cycle for synchronized conveyor or motion control
  • Your system includes legacy PROFIBUS DP devices (drives, I/O) that must co-exist with modern PROFINET nodes on a single CPU
  • Your 24 VDC supply can deliver up to 0.9 A continuous and handle a 4.7 A inrush at startup
  • Your program fits within 300 KB program memory and 1 MB data memory

If you are starting a new installation, the successor model 6ES7512-1SM03-0AB0 is the correct specification — the 6ES7512-1SK01-0AB0 is discontinued and inventory is declining. If your program complexity exceeds 300 KB or requires more than 20 integrated I/O, evaluate the SIMATIC S7-1500F 1515F or 1518F variants instead.

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What the CPU 1512SP F-1 PN Actually Does in a Control System

The 6ES7512-1SK01-0AB0 is the central processing unit for SIMATIC S7-1500F control systems. It executes both standard and failsafe logic in the same CPU, which eliminates the need for a dedicated safety PLC running in parallel with the standard controller. For machine builders and system integrators, that integration reduces panel wiring complexity, lowers component count, and removes one potential single point of failure from the safety architecture.

With a bit performance of 48 ns, the CPU handles high-speed instruction cycles suitable for conveyor sequencing, pick-and-place robot coordination, and tool actuation based on workpiece position. The integrated PROFINET 3-port switch means three PROFINET nodes can connect directly to the CPU without an external managed switch — a meaningful panel cost reduction on compact machines. PROFIsafe V2.4 and V2.6 support handles safety-rated I/O over standard PROFINET infrastructure. On the same unit, the PROFIBUS DP master interface accommodates up to 48 connections, with 4 reserved for engineering stations and HMI, giving the CPU reach into legacy drive and I/O networks without a separate gateway.

The 300 KB program memory and 1 MB data memory are appropriate for single-machine or single-conveyor applications with moderate safety logic. The 20 integrated digital inputs and 20 integrated digital outputs cover basic sensor and actuator wiring without adding an external I/O module, though any expansion beyond that count requires additional modules on the PROFINET or PROFIBUS network.

Typical System Architecture for the 6ES7512-1SK01-0AB0

The 6ES7512-1SK01-0AB0 sits at the top of the control hierarchy as the master CPU, receiving engineering and HMI traffic on its PROFINET interface while simultaneously managing distributed I/O and legacy field devices.

  • Engineering PC running STEP 7 TIA Portal V17 (or V13 SP1 Update 4 for firmware V1.8) connects via PROFINET Ethernet to the CPU's integrated 3-port switch
  • HMI panel or SCADA system connects to a second PROFINET port on the integrated switch — no external managed switch required for a basic three-node topology
  • PROFINET remote I/O stations (ET 200SP nodes, variable-frequency drives with PROFINET adapters, safety I/O) connect to the third PROFINET port or via daisy-chain through upstream devices
  • Legacy PROFIBUS DP devices (older drives, third-party I/O modules, sensors with PROFIBUS interfaces) connect via the CPU's integrated PROFIBUS master interface at up to 12 Mbit/s
  • Local discrete sensors and actuators wire directly to the 20 integrated digital inputs and 20 integrated digital outputs on the CPU module itself

Industries and Applications Where This CPU Is the Right Fit

Automotive assembly lines use the 6ES7512-1SK01-0AB0 for conveyor belt position tracking with tool actuation — drilling, welding, or fastening — where failsafe emergency stop interlocks must be certified to PLe without a separate safety relay panel. The isochronous PROFINET mode at 625 µs cycle time supports synchronized multi-motor drive coordination on the same network.

Food and beverage packaging lines benefit from the SIL 3 machine guarding interlock capability. Presence sensing at infeed and discharge points, door interlocks on enclosures, and light curtain inputs connect directly to the integrated I/O or via PROFIsafe-compatible remote I/O — all managed by a single CPU running both production and safety logic.

Pharmaceutical manufacturers with dosing or containment applications requiring functional safety documentation find the IEC 61508 SIL 3 certification and built-in I&M data (I&M0 through I&M3) support simplifies compliance audits. The CPU's identification and maintenance data is accessible directly from TIA Portal without additional instrumentation.

Machine tool builders and OEM machinery manufacturers integrating legacy PROFIBUS drives alongside modern PROFINET peripherals use this CPU to avoid the cost and complexity of a separate PROFIBUS-to-PROFINET gateway or bridge device. A single controller handles both protocol domains.

Application Typical Deployment
Conveyor control with safety interlocks CPU manages position tracking, tool on/off, and failsafe E-stop without external safety relay
Multi-axis robotic material handling PROFINET IRT at 625 µs cycle synchronizes robot and conveyor drives; PROFIsafe covers safety I/O
Machine guarding and access control Door interlocks and light curtains wired to integrated I/O or PROFIsafe remote nodes; SIL 3 certified
Legacy PROFIBUS drive integration PROFIBUS DP master connects older drives; PROFINET handles modern distributed I/O — one CPU, two networks
ET 200SP distributed I/O control CPU mounted in ET 200SP frame as master; remote PROFINET nodes extend I/O across large machines
Pharmaceutical dosing and containment SIL 3 failsafe logic with I&M data support for compliance documentation; single CPU architecture

Key Specifications Engineers Check Before Ordering

Specification Value
Bit performance 48 ns
Program memory 300 KB
Data memory 1 MB
Integrated digital I/O 20 inputs / 20 outputs
Rated supply voltage 24 VDC (range: 19.2–28.8 VDC)
Rated current / maximum current 0.6 A / 0.9 A; inrush 4.7 A (I²t = 0.14 A²·s)
PROFINET Integrated 3-port switch, 100 Mbps, IRT, PROFIsafe V2.4/V2.6, min. cycle 625 µs
PROFIBUS DP Master (48 connections, 4 reserved); RS485, up to 12 Mbit/s
Safety certification SIL 3 (IEC 61508), PLe (ISO 13849-1); PFDavg < 2.00E-05, PFH < 1.00E-09
Dimensions (W × H × D) 100 mm × 117 mm × 75 mm; weight approx. 310 g

Full technical specifications are available on the product page at LeadTime.ca.

6ES7512-1SK01-0AB0 vs 6ES7512-1SM03-0AB0 and Larger S7-1500F Models

Model Status Program Memory Failsafe Best For
6ES7512-1SK01-0AB0 (CPU 1512SP F-1 PN) Discontinued Oct 2025 300 KB SIL 3 / PLe Spare parts for existing installations; compact failsafe applications
6ES7512-1SM03-0AB0 (Successor) Active / Current Verify with Siemens SIL 3 / PLe All new installations replacing 6ES7512-1SK01-0AB0
SIMATIC S7-1500 Standard (Non-F) Active Varies by model None Non-safety-critical machine control where SIL 3 is not required
SIMATIC S7-1500F 1515F / 1518F Active 750 KB+ SIL 3 / PLe Complex multi-axis motion, large safety logic programs exceeding 300 KB

If your architecture requires the integrated PROFINET switch and PROFIBUS DP master with SIL 3 failsafe in a compact form factor and you are sourcing spare parts for an active installation, the 6ES7512-1SK01-0AB0 remains the correct part — check current stock and pricing at LeadTime.ca.

Expert Verdict: Honest Assessment for Purchase Decision

The 6ES7512-1SK01-0AB0 is genuinely well-suited for what it was designed to do: single-machine or single-conveyor safety-critical control where the engineer needs SIL 3 / PLe failsafe logic, dual-protocol networking, and a compact footprint without the cost or panel space of a larger S7-1500F. The 48 ns bit performance is fast enough for isochronous motion control at 625 µs, the integrated 3-port PROFINET switch eliminates the need for an external managed switch in basic topologies, and the PROFIBUS DP master handles up to 48 connections covering most legacy device integration scenarios. For that defined scope, this CPU has consistently been specified in automotive conveyor and pharmaceutical machine guarding applications where exactly these constraints apply.

The limits are also real. The 300 KB program memory becomes a constraint on complex safety programs with many function blocks, and the 20 integrated digital I/O count means any project beyond a basic machine will need external modules — adding cost and panel space that partially offsets the compact CPU advantage. Most importantly, discontinuation effective October 1, 2025 means new project specifications should not use this part number. Inventory is available but declining. If you are evaluating this CPU for a new build, the 6ES7512-1SM03-0AB0 successor is the correct path. If you are sourcing spares for existing systems, order now while stock remains accessible and factor in lead time risk as inventory thins.

From a procurement standpoint, the CPU module alone typically lands in the €800–1,200 range through industrial distributors, with North American pricing running 15–25% higher. Required accessories — BusAdapter (BA 2x RJ45 or BA 2x FC) and a compatible Memory Card — add €80–250 to the entry cost. Stock units from established distributors historically ship in 1–2 weeks, but post-discontinuation availability is narrowing. If this matches your spare parts requirements, view current stock and pricing at LeadTime.ca before committing to a build schedule.

For volume pricing, lead time confirmation, or to discuss successor model migration before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Wiring and Installation Overview

  • Supply 24 VDC within the 19.2–28.8 VDC range; budget 0.9 A for peak continuous draw and ensure your supply can absorb a 4.7 A inrush at startup without tripping overcurrent protection — the CPU provides reverse polarity protection and supply voltage monitoring via the PWR LED
  • Install the BusAdapter (BA 2x RJ45 for standard Ethernet or BA 2x FC for fiber in high-EMI environments) before connecting PROFINET cables — the integrated 3-port switch activates through the BusAdapter; use Cat5e or Cat6 shielded cable in industrial environments
  • For PROFIBUS DP wiring, use Type A or B twisted pair cable (120 Ω characteristic impedance) and fit termination resistors at both ends of each segment; maximum cable length is 1,200 m at 1.5 Mbps and 400 m at 12 Mbps
  • Insert the Memory Card into the dedicated slot before powering up — program storage requires the card; the multi-hot-swapping feature allows card insertion without powering down the CPU
  • Refer to manufacturer wiring documentation for specific terminal pinout of the 20 digital inputs and 20 digital outputs; confirm output load ratings match actuator requirements before energizing outputs for the first time

Required Accessories and Compatible Expansion

Two accessories are required for standard operation and must be budgeted alongside the CPU module itself. Additional expansion modules connect via PROFINET or PROFIBUS when the 20 integrated I/O channels are insufficient.

  • BusAdapter BA 2x RJ45 — provides the two RJ45 Ethernet connectors for PROFINET port 1 and port 2; required for standard copper Ethernet connectivity
  • BusAdapter BA 2x FC — fiber optic alternative to BA 2x RJ45; specified for EMI-sensitive environments or long-distance inter-cabinet PROFINET runs
  • SIMATIC Memory Card — required for program storage; select capacity appropriate for your TIA Portal project size (typically 2 MB or larger)
  • ET 200SP I/O modules — extend digital, analog, or specialty I/O count via PROFINET when the integrated 20-in/20-out channels are insufficient
  • PROFIBUS DP slave modules — legacy drives, third-party I/O, or older instrumentation connect via the CPU's PROFIBUS DP master interface at up to 48 connections per segment

What Engineers Get Wrong When Ordering This Part

Before placing an order for the 6ES7512-1SK01-0AB0, work through each of the following checks — incorrect assumptions on any one of these has caused costly rework on installation projects.

  1. Confirm failsafe (safety-rated) logic is required in control strategy — non-failsafe SIMATIC S7-1500 models are cheaper and simpler if SIL 3 is not needed
  2. Verify PROFINET + PROFIBUS dual connectivity is needed — some S7-1500 variants have PROFINET only
  3. Check that 300 KB program memory is sufficient — larger programs may require 1512SP (non-failsafe) or 1515F/1518F models
  4. Confirm 20 digital I/O (builtin) matches I/O count — additional modules add cost and panel space; count actual discrete sensors/actuators first
  5. Validate 24 VDC supply availability at 0.9A max draw — power supply must be rated accordingly; inrush current is 4.7A
  6. Check that successor model 6ES7512-1SM03-0AB0 is acceptable if product discontinuation affects spare parts or support
  7. Ensure STEP 7 TIA Portal license is available (V17 or higher for FW V2.9, or V13 SP1 Update 4 for FW V1.8)
  8. Confirm that BusAdapter (BA 2x RJ45 or BA 2x FC) and Memory Card are budgeted as required accessories

If any of these checks raises a question before you order, contact the LeadTime.ca team — we can confirm part compatibility and availability before you commit.

Frequently Asked Questions

Is the 6ES7512-1SK01-0AB0 still available to purchase, or is it completely obsolete?

The product was discontinued effective October 1, 2025, but inventory continues to be available through industrial distributors as of early 2026. Stock levels are declining post-discontinuation. For new installations, the successor model 6ES7512-1SM03-0AB0 is the correct specification. For spare parts supporting existing systems, order while inventory remains accessible — lead times on discontinued parts can extend significantly as stock depletes.

What TIA Portal version is required to program the 6ES7512-1SK01-0AB0?

The firmware version determines the required TIA Portal release. Firmware V2.9 requires STEP 7 TIA Portal V17 or higher. Firmware V1.8 requires at minimum V13 SP1 Update 4. Verify the firmware version on the physical unit or in the Siemens product catalog entry before starting a new project or migrating an existing one — mismatched versions prevent program download.

Does the CPU 1512SP F-1 PN require an external safety module to achieve SIL 3 / PLe certification?

No. The SIL 3 (IEC 61508) and PLe (ISO 13849-1) failsafe logic is integrated directly into the CPU 1512SP F-1 PN. No separate safety PLC module or safety relay is required for the CPU itself to execute failsafe logic. PROFIsafe V2.4 and V2.6 support extends that safety integrity to connected remote I/O devices over standard PROFINET infrastructure. The PFDavg is less than 2.00E-05 in low-demand mode and PFH is less than 1.00E-09 in continuous mode over a 20-year service life with 100-hour repair time.

What happens if the program exceeds 300 KB on the 6ES7512-1SK01-0AB0?

TIA Portal will report insufficient memory and the download operation will abort. If your safety logic and standard program blocks together exceed 300 KB, the correct path is to migrate to a larger SIMATIC S7-1500F model — the 1515F or 1518F offer 750 KB or more of program memory. Optimizing user code and reviewing data block allocations can recover some headroom, but 300 KB is a hard limit on this CPU.

Can the 6ES7512-1SK01-0AB0 connect to both PROFINET and PROFIBUS devices simultaneously?

Yes. The CPU integrates both a 3-port PROFINET switch (100 Mbps, IRT capable, autonegotiation) and a PROFIBUS DP master interface (RS485, up to 12 Mbit/s, 48 connections maximum). Both interfaces operate simultaneously, allowing the CPU to manage modern PROFINET I/O and legacy PROFIBUS devices — drives, older I/O modules, third-party instrumentation — from a single controller without a separate gateway or bridge.

What is the minimum PROFINET cycle time for isochronous mode on this CPU?

The minimum OB 6x cycle time for PROFINET isochronous real-time (IRT) mode is 625 µs. All PROFINET devices in the isochronous network segment must also support IRT at that cycle time. This is the specification that qualifies the CPU for synchronized multi-axis motion control and precise conveyor sequencing where consistent timing between the controller and drives is a hard requirement.

Why Order From LeadTime.ca

  • LeadTime.ca ships the 6ES7512-1SK01-0AB0 and the successor 6ES7512-1SM03-0AB0 worldwide — no regional sourcing restrictions
  • We source hard-to-find and discontinued SIMATIC S7-1500F inventory that standard distribution channels no longer stock
  • Volume pricing and lead time confirmation available before you commit to a purchase order — contact us with your project quantities
  • Fast response from a team that understands SIMATIC S7-1500F architecture, accessories, and discontinuation migration paths

At-a-Glance Summary

  • Catalog number: 6ES7512-1SK01-0AB0 — CPU 1512SP F-1 PN, SIMATIC S7-1500F family
  • Discontinued effective October 1, 2025; successor model is 6ES7512-1SM03-0AB0
  • SIL 3 (IEC 61508) and PLe (ISO 13849-1) failsafe certified; PFH less than 1.00E-09 in continuous mode
  • 48 ns bit performance; 300 KB program memory; 1 MB data memory
  • 20 integrated digital inputs and 20 integrated digital outputs built into the CPU module
  • Integrated 3-port PROFINET switch at 100 Mbps with IRT support; minimum isochronous cycle 625 µs
  • PROFIBUS DP master: up to 48 connections, RS485, maximum 12 Mbit/s
  • 24 VDC supply; rated 0.6 A, maximum 0.9 A; inrush 4.7 A (I²t = 0.14 A²·s)
  • Dimensions: 100 mm × 117 mm × 75 mm; weight approximately 310 g
  • Operating temperature: -25°C to +60°C horizontal; -25°C to +50°C vertical
  • Requires BusAdapter (BA 2x RJ45 or BA 2x FC) and Memory Card — both must be budgeted separately
  • STEP 7 TIA Portal V17 or higher required for firmware V2.9; V13 SP1 Update 4 minimum for firmware V1.8
  • Typical distributor entry cost (CPU + required accessories): €900–1,450 / approximately USD $1,000–1,600