Siemens S5 End-of-Life: Complete Timeline & Implications
Complete timeline of the Siemens SIMATIC S5 PLC from introduction in 1979 to end-of-life on 30.09.2020. What the EOL means for spare parts, repairs, software, and your migration planning.
Siemens S5 End-of-Life: Complete Timeline & Implications
The Siemens SIMATIC S5 product lifecycle ended on 30 September 2020. Since 1 October 2020, Siemens no longer provides spare parts, repairs, or technical support for any S5 product. This article provides the complete timeline from introduction to end-of-life, explains what this means for plants still running S5 systems, and outlines the realistic options available today.
The Complete S5 Timeline
| Year | Event |
|---|---|
| 1979 | SIMATIC S5 series launched, replacing the SIMATIC S3. First models: S5-110, S5-130, S5-150 |
| 1984 | S5 U (Universal) series introduced: S5-90U, S5-95U, S5-100U, S5-115U, S5-135U, S5-155U. Major commercial success begins |
| ~1988 | STEP 5 programming software moves from CP/M to MS-DOS |
| 1994 | SIMATIC S7 launched (S7-200, S7-300, S7-400). Siemens begins recommending S7 for new projects |
| ~1996 | STEP 5 available on Windows. Final version: STEP 5 V7.2 |
| 2003–2006 | S5 production discontinued. Different models phased out at different dates. Siemens commits to 10+ years of spare parts |
| 2009 | S7-1200 launched (replaces S7-200 class) |
| 2012 | S7-1500 launched (intended successor for S7-300/400) |
| 30.09.2020 | S5 End-of-Life: Siemens stops all spare parts supply and repairs |
| 01.10.2020 | No new S5 parts available from Siemens. No repairs accepted. Only third-party suppliers remain |
Key fact: A few specific S5 items remained available after 01.10.2020 (order numbers 6ES5980-0DA11, 6ES5980-0AE11, 6ES5980-0MA11, 6ES5980-0NC11, and 6EW1000-7AA). These are battery and accessory items, not CPUs or I/O modules.
What "End-of-Life" Actually Means
What Siemens no longer provides:
- Spare parts: No CPUs, I/O modules, power supplies, communication modules, or racks available from Siemens
- Repairs: Siemens will not accept any S5 hardware for repair, regardless of the issue
- Technical support: No phone or online support for S5-related questions
- Software updates: STEP 5 V7.2 was the final release. No security patches, no Windows compatibility updates
- Documentation: Existing documentation remains accessible on the Siemens support portal, but no new content is created
What still works:
- Your existing S5 hardware continues to run. End-of-life does not mean the PLC stops working
- Your existing STEP 5 software continues to work — on the operating system it was designed for (Windows XP/7)
- Third-party spare parts are available from refurbished parts suppliers across Europe and worldwide
- Third-party repair services exist but with limited availability and no manufacturer warranty
- S5→S7 converter tool in STEP 7 V5.x still functions (see our converter tool guide)
The Spare Parts Problem
The S5 spare parts situation deteriorates predictably:
2020–2023 (Post-EOL Phase 1): Third-party suppliers had large inventories. Prices were 20–50% above original Siemens prices. Most parts available within days.
2024–2026 (Post-EOL Phase 2 — Current): Inventories are shrinking. Common parts (standard I/O modules, power supplies) are still available. Specialized parts (specific CPUs, communication processors, fail-safe modules) are becoming scarce. Prices for some items are 2–5× the original price.
2027+ (Post-EOL Phase 3 — Projected): Only refurbished and pulled-from-service parts available. No quality guarantee. Lead times of weeks to months. Prices unpredictable. Some parts may become completely unavailable.
The Most Critical Parts
Not all S5 parts are equally at risk. The most critical shortage items:
| Part Category | Risk Level | Why |
|---|---|---|
| CPUs (e.g., CPU 948, CPU 928B) | Very High | Complex ICs, no generic replacement, each CPU type unique |
| Communication Processors (CP 524, CP 543) | Very High | Protocol-specific, no modern equivalent |
| Fail-Safe modules (F-modules) | Very High | Certified for safety, cannot be replaced with generic parts |
| Analog I/O modules | High | Specific resolution and range combinations |
| Power Supplies | Medium | Generic alternatives sometimes possible with adapter |
| Digital I/O modules | Medium | Most common, largest third-party inventory |
| Racks/Backplanes | Low | Mechanical parts, rarely fail |
The STEP 5 Software Problem
STEP 5 V7.2 was the final release. It is officially supported on Windows XP (SP3) and Windows 7 (32-bit). This creates a chain of problems:
Operating system: Windows XP reached end-of-life in April 2014. Windows 7 reached end-of-life in January 2020. Running either system on a network-connected PC is a cybersecurity risk.
Hardware: Modern PCs do not ship with 32-bit operating systems. Finding or maintaining a PC that runs STEP 5 reliably requires legacy hardware or virtualization (which Siemens does not officially support).
Programming devices: The Siemens PG (Programming Device) interfaces like the AG-Link adapter for the S5 serial interface are no longer manufactured. USB-to-serial converters require specific drivers that may not work on modern systems.
Practical workaround: Many plants maintain a dedicated offline laptop with Windows XP/7 specifically for STEP 5. This is acceptable as long as it never connects to the plant network. But it is a single-point-of-failure with no backup strategy — if that laptop dies, access to the S5 program is at risk.
The Bigger Picture: Siemens PLC Lifecycle
The S5 end-of-life is not an isolated event. It is the first wave in a series of Siemens PLC phase-outs:
| System | Production End | Spare Parts End | Current Status |
|---|---|---|---|
| SIMATIC S5 | 2003–2006 | 30.09.2020 | Fully EOL. No Siemens support. |
| SIMATIC S7-300 (PM410) | 01.10.2025 | ~Oct 2033 (est.) | Production ending now |
| SIMATIC S7-400 | "Beyond 2030" | TBD | Still available but future limited |
| SIMATIC S7-1200 (1st gen) | 01.11.2026 | TBD | Current gen still in production |
| SIMATIC S7-1500 | Active | Active | Current recommended platform |
The pattern is clear: Every Siemens PLC generation follows the same lifecycle — active production → phase-out announcement → 10 years spare parts → end-of-life. Plants running S7-300 today face the same situation in 2033 that S5 plants faced in 2020.
For a detailed analysis of the S7-300/400 situation, see our S7-300 End-of-Life planning guide.
Your Options Today (2026)
Option 1: Migrate to S7-1500 (Recommended)
The only long-term solution. Migrate the S5 program to S7-1500 using TIA Portal. This is what Siemens recommends, and for good reason — the S7-1500 is actively developed, has a 20+ year lifecycle ahead, and supports modern features (OPC UA, web server, integrated safety).
Cost: €5,000–100,000+ per machine depending on complexity (see migration cost guide)
When: As soon as possible. Every month of delay means higher risk and higher cost.
Option 2: Run Until Failure
Keep the S5 running and hope nothing breaks. This is not a strategy — it is a gamble. When the CPU fails at 2 AM on a Friday and the third-party supplier needs 3 weeks to source a replacement, the "savings" from avoiding migration evaporate in a single weekend of lost production.
When this is (temporarily) acceptable: For machines scheduled for decommissioning within 1–2 years. Invest only in critical spare parts, not in migration.
Option 3: S5-to-S7 Emulator/Adapter
Products exist that physically replace the S5 CPU but run the S5 program in emulation. This avoids program conversion but does not solve the fundamental problems:
- The program is still undocumented S5 code
- STEP 5 is still needed for modifications
- No path to modern features (OPC UA, web diagnostics, cloud connectivity)
- Limited to the I/O capabilities of the original S5 system
When this makes sense: As a bridge solution to buy time for a proper migration. Not as a permanent strategy.
How PLCcheck Pro Helps
PLCcheck Pro is built for exactly this situation — S5 code that needs to be understood, documented, and migrated:
- Upload S5 AWL code → get instant plain-language explanations
- Automatic timer conversion → all KT values mapped to IEC timers
- Address mapping → complete DW→DBW conversion for data blocks
- Migration documentation → exportable reports for planning and execution
Whether you migrate in-house or hire an integrator, PLCcheck Pro saves days of manual analysis work.
Frequently Asked Questions
Can I still buy S5 spare parts?
Not from Siemens. Third-party suppliers still offer refurbished and pulled-from-service parts, but availability is declining and prices are rising. For critical CPUs and communication modules, lead times can be weeks.
Is my STEP 5 software still legal to use?
Yes. Your existing STEP 5 license remains valid. The software works as before. But it will not receive updates, and Siemens will not help with installation or compatibility issues on modern operating systems.
How many S5 systems are still running worldwide?
No official number exists. Industry estimates suggest tens of thousands of S5 installations are still active, primarily in established manufacturing countries (Germany, Italy, France, Benelux, USA). Many are in industries with long machine lifecycles: automotive, chemicals, food processing, steel, and water treatment.
What is the recommended migration target?
Siemens recommends the S7-1500 with TIA Portal. Do not migrate to S7-300 — it is itself approaching end-of-life.
Maintained by PLCcheck.ai. Last update: March 2026. Not affiliated with Siemens AG.
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