S7-300/400 End-of-Life: What Plant Operators Need to Plan Now
Complete timeline for the Siemens S7-300 and S7-400 product phase-out. Key dates, spare parts availability, price implications, and a practical migration planning guide for plant operators.
S7-300/400 End-of-Life: What Plant Operators Need to Plan Now
The Siemens SIMATIC S7-300 and ET 200M reached product discontinuation (PM410) on October 1, 2025. No new S7-300 components can be ordered from Siemens. Spare parts are guaranteed only until approximately October 2033. After that, availability depends entirely on remaining stock at premium prices. The S7-400 follows a similar but slightly extended timeline. The migration target for both is the S7-1500 with TIA Portal.
The Official Timeline
S7-300 / ET 200M
| Date | Milestone | What It Means |
|---|---|---|
| October 1, 2023 | PM400 — Product discontinuation announced | Siemens officially declares phase-out. No future development. |
| October 1, 2025 | PM410 — End of standard deliveries | No new orders for S7-300/ET 200M components. 267+ assemblies affected. |
| ~October 2033 | PM490 — End of spare parts supply | Siemens guarantees spare parts for 10 years after PM400. After this date, no guaranteed availability. |
What happened on October 1, 2025: Over 267 individual S7-300 and ET 200M product numbers moved from "orderable as new" to "spare parts only." This means:
- No new installations with S7-300 are possible
- Spare parts are available but in limited quantities
- Prices are increasing due to higher storage and logistics costs for discontinued products
- System extensions or capacity expansions using S7-300 are no longer feasible
S7-400
The S7-400 follows a slightly different timeline because of its entrenched position in high-availability process control systems (particularly with PCS 7):
| Status | Details |
|---|---|
| Current phase | Active phase-out, but availability extended beyond S7-300 |
| Siemens statement | "Availability beyond 2030" for S7-400 series |
| Spare parts | Expected to follow the same 10-year rule after PM400 |
| Migration target | S7-1500 (standard) or S7-1500 R/H (redundant, for PCS 7) |
The S7-400 is particularly critical for process industries (chemical, pharmaceutical, oil & gas) where PCS 7 systems rely on S7-400 CPUs. Migration here is more complex because it involves not just the PLC but the entire DCS architecture.
Price Impact: What to Expect
Siemens follows a consistent pattern with discontinued products: prices increase progressively during the spare parts phase.
Based on precedent from previous phase-outs (S5, ET200S):
| Phase | Expected Price Impact |
|---|---|
| 2023–2025 (PM400–PM410) | Prices stable or slight increase (5–15%) |
| 2025–2028 (early spare parts phase) | Moderate increase (20–50%) above pre-discontinuation price |
| 2028–2033 (late spare parts phase) | Significant increase (50–200%) as stock depletes |
| After 2033 (post-PM490) | Third-party market only, 3–10× original price (same pattern as S5) |
Real example from the ET200S phase-out: When ET200S entered its spare parts phase, prices increased significantly within the first two years. Several plant operators reported 2–3× price increases for common modules within 18 months of PM410.
What You Should Do Now
If You Have S7-300 Systems Running
Immediate actions (2026):
- Inventory all S7-300 hardware — Every CPU, I/O module, communication processor, power supply. Record order numbers, firmware versions, and quantities.
- Stock critical spare parts now — Before prices increase further. Priority: CPU modules, power supplies, and the most-used I/O module types.
- Back up every program — Verified offline copies of all S7-300 projects in STEP 7 Classic.
- Assess your TIA Portal readiness — Do you have TIA Portal licenses? Do your engineers know TIA Portal?
Medium-term planning (2026–2028): 5. Create a migration roadmap — Prioritize systems by criticality and age. Migrate the oldest and most critical first. 6. Select S7-1500 CPUs — Map your S7-300 CPUs to S7-1500 equivalents. The S7-1500 offers direct migration support in TIA Portal. 7. Budget for migration — Use the migration cost guide to plan budgets. 8. Train your team — TIA Portal training (if not already done). The S7-1500 programming model is different from STEP 7 Classic.
Migration execution (2027–2033): 9. Migrate in phases — Start with non-critical systems to build experience. Move to production-critical systems with confidence. 10. Use TIA Portal migration tools — TIA Portal includes a project migration wizard that can import STEP 7 V5.x projects and convert them to TIA Portal format.
If You Have S7-400 Systems Running
The situation is less urgent but still requires planning:
- S7-400 availability extends beyond 2030
- For PCS 7 systems, Siemens offers a specific migration path to S7-1500 with PCS 7 V10
- Redundant systems (H-CPUs) migrate to the new S7-1500 R/H platform
- Start planning now, but execution can be phased over a longer period
S7-300 → S7-1500: The Technical Migration
The S7-300 to S7-1500 migration is significantly simpler than S5 to S7 because:
Same programming language: Both use STEP 7 / TIA Portal. AWL, KOP, FUP, SCL all carry over (though AWL runs in emulation mode on S7-1500).
TIA Portal migration wizard: TIA Portal can import STEP 7 V5.x projects directly. The wizard converts hardware configuration, program blocks, and symbol tables.
Compatible I/O concepts: S7-300 ET 200M distributed I/O migrates to ET 200SP or ET 200MP. Standard PROFIBUS configurations migrate to PROFINET.
Main technical challenges:
- Optimized data blocks: S7-1500 uses optimized (non-addressed) data blocks by default. Legacy programs that access DB bytes directly (e.g., pointer operations on DBBs) may need adjustment.
- AWL emulation: AWL code runs on S7-1500 but in emulation mode, which may be slightly slower. Converting to SCL is recommended for performance-critical sections.
- Memory format differences: S7-1500 uses a different internal memory layout. Most code works unchanged, but edge cases with direct memory access may need attention.
See our complete S5→S7 migration guide for detailed technical steps. Many concepts apply to S7-300→S7-1500 as well.
The Bigger Picture: Siemens Lifecycle Strategy
Siemens follows a predictable product lifecycle:
| Platform | Introduced | PM400 (Discontinuation) | PM490 (End of Spare Parts) |
|---|---|---|---|
| S5 | 1979 | ~2010 | September 30, 2020 |
| S7-300 | 1994 | October 1, 2023 | ~October 2033 |
| S7-400 | 1996 | Ongoing phase-out | ~2035+ (estimated) |
| S7-1200 (1st gen) | 2009 | November 1, 2026 | ~2036 |
| S7-1500 | 2013 | Active — current platform | Not announced |
The S7-1500 is Siemens' current flagship platform and will be supported for many years. Migrating to S7-1500 today means you are on a platform with at least 10–15 years of guaranteed support ahead.
PLCcheck Pro can analyze your S7-300 program and generate a migration assessment — block inventory, complexity analysis, and S7-1500 CPU recommendation. Start your assessment →
Frequently Asked Questions
Can I still buy S7-300 components?
Only as spare parts, in limited quantities, at increasing prices. No new installations. Standard deliveries ended October 1, 2025.
Will my S7-300 stop working after 2033?
No. The hardware continues to run. But if a component fails after 2033, Siemens does not guarantee replacement parts. You would depend on the third-party refurbished market — the same situation S5 users face today.
Is TIA Portal backwards compatible with STEP 7 Classic projects?
Yes. TIA Portal includes a migration wizard that imports STEP 7 V5.x projects. The conversion is not always perfect (especially for complex AWL code and hardware-specific configurations), but it handles the majority of the migration automatically.
Should I migrate S7-300 to S7-1500 or S7-1200?
S7-1500 for most industrial applications. The S7-1200 is designed for smaller, simpler machines and does not support AWL at all. If your S7-300 program uses AWL, it can only run on S7-1500 (in emulation mode). S7-1500 also offers more memory, faster processing, and better diagnostic features.
What about the S7-1200 first generation discontinuation?
The first generation of S7-1200 was declared discontinued as of November 1, 2026. If you have first-gen S7-1200 systems, check whether your CPU is affected and plan accordingly.
Maintained by PLCcheck.ai. Last update: March 2026. Not affiliated with Siemens AG.
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