If you’re running a SIMATIC S7-300 system in your plant, you’ve got a decision to make. Siemens officially discontinued the S7-300 and ET 200M product lines on October 1, 2025. That means no new parts, limited spare parts availability, and significantly higher prices for whatever stock remains.
The question isn’t whether to migrate. It’s what to migrate to, and how to do it without breaking your production schedule or your budget.
The SIMATIC S7-1500 is Siemens’ engineered replacement. It’s not just a faster version of the S7-300. It’s a fundamentally different architecture with integrated safety, built-in motion control, and modern communication protocols that actually make sense for Australian industrial conditions.
At Endless Process Automation, we’ve helped sites across Queensland navigate this migration. From the Bowen Basin to Gladstone, we’ve seen what works and what catches engineers off guard. Here’s what you need to know.
Why the S7-300 is being discontinued (and what P.M410 means for you)
Siemens uses a product lifecycle coding system. P.M300 meant regular availability. P.M400 meant phase-out. P.M410, which took effect October 1, 2025, means spare parts only.
Here’s what that actually means on the ground:
- No new assemblies: You can’t order new S7-300 CPUs or ET 200M modules for expansion projects
- Spare parts pricing: Siemens increases prices significantly for P.M410 products due to storage, production, and logistics costs
- Limited availability: Spare parts are allocated in limited quantities. If you need a specific CPU during a breakdown, you might be waiting weeks
- No technical evolution: No firmware updates, no new features, no security patches
If you’re still running S7-300, you’re now managing an obsolete system. The risk isn’t just the hardware failing. It’s the lead time to get replacement parts when it does.
S7-1500 vs S7-300: What’s actually different?
Let’s break down the technical differences that matter for migration planning.
Engineering environment
The S7-300 used STEP 7 Classic. The S7-1500 uses TIA Portal. This isn’t just a software update. It’s a completely different engineering philosophy.
TIA Portal integrates programming, visualization, and diagnostics in one environment. You don’t bounce between STEP 7 for the PLC, WinCC for the HMI, and separate tools for drives. Everything lives in one project file with shared tag databases.
For migration, this means your existing STEP 7 programs need conversion. Siemens provides migration tools, but you’ll need to validate timing, address assignments, and communication configurations. It’s not a straight copy-paste.
Communication architecture
The S7-300 was built around PROFIBUS. The S7-1500 is built around PROFINET.
PROFINET is Ethernet-based, faster, and uses standard network infrastructure. You can diagnose it with standard IT tools. It integrates with SCADA systems more cleanly. And it’s what modern field devices expect.
The S7-1500 CPUs have PROFINET integrated. You don’t need a separate communications processor like you did with many S7-300 configurations.
Integrated functionality
Here’s where the S7-1500 really separates itself:
| Function | S7-300 Approach | S7-1500 Approach |
|---|---|---|
| Motion control | Separate FM modules or external motion controllers | Integrated in every CPU |
| Safety | Separate F-CPU required | F-CPUs available with Safety Integrated |
| System diagnostics | Limited, required additional software | Integrated web server on every CPU |
| Security | Basic password protection | Know-how protection, access control, encrypted communication |
| OPC UA | Not native | Built-in server for Industry 4.0 connectivity |
Source: Siemens S7-1500 Product Overview
Physical differences
The S7-1500 uses a different form factor than the S7-300. Mounting dimensions, wiring terminals, and connector types are all different. You can’t just pull out a 315-2 DP and drop in a 1515-2 PN.
This means migration planning needs to account for:
- Control cabinet layout changes
- Wiring harness modifications
- Terminal strip updates
- Potential I/O module replacements (ET 200M to ET 200MP)
Key S7-1500 features for Australian industrial applications
Australian conditions are tough on automation equipment. The S7-1500 has specific features that matter here.
Integrated safety for hazardous areas
Mining and oil & gas applications in Queensland often need safety-rated control systems. The S7-1500 F-CPUs (fail-safe versions) integrate safety functionality without a separate safety PLC.
This matters because:
- You save cabinet space (critical in cramped skids)
- You reduce wiring complexity
- You program safety and standard logic in the same TIA Portal project
- You meet SIL 3 / PLe requirements for hazardous area applications
Environmental considerations
The S7-1500 is rated IP20, meaning it’s designed for control cabinet installation. For Australian sites dealing with:
- Pilbara dust: You’ll need sealed cabinets with positive pressure
- Gladstone humidity: Climate control and desiccant systems are essential
- 50°C+ ambient: The S7-1500 CPUs operate up to 60°C with derating, but cabinet cooling becomes critical
The key is proper enclosure design. The PLC itself is solid. We’ve installed S7-1500 systems in coal handling plants and water treatment facilities across Queensland that have run for years without issues.
Motion control for materials handling
Every S7-1500 CPU includes motion control functionality. For conveyor systems, packaging lines, and positioning applications, you don’t need separate motion controllers.
The Technology CPUs (1511T, 1515T, etc.) extend this with:
- Extended gear synchronization
- Cyclic cam control
- Kinematics for portal systems and robots
If you’re running materials handling equipment, this integration saves hardware costs and simplifies commissioning.
Remote diagnostics
The integrated web server on every S7-1500 CPU lets you access diagnostic information from any browser. For sites in remote Queensland locations, this means:
- Faster troubleshooting without driving to site
- Reduced downtime during breakdowns
- Better support from integrators who can see what you see
CPU selection guide: Which S7-1500 is right for your application?
Selecting the right CPU depends on program size, I/O count, communication requirements, and safety needs. Here’s a practical breakdown:
| CPU Model | Program Memory | Data Memory | Communication | Typical Applications | Est. Price (AUD)* |
|---|---|---|---|---|---|
| CPU 1511-1 PN | 300KB | 1.5MB | 1x PROFINET | Small machines, simple processes | ~$2,400 |
| CPU 1513-1 PN | 600KB | 2.5MB | 1x PROFINET | Mid-size applications | ~$5,300 |
| CPU 1515-2 PN | 1MB | 4.5MB | 2x PROFINET | Complex processes, line integration | ~$7,800 |
| CPU 1516-3 PN/DP | 2MB | 7.5MB | PROFINET + PROFIBUS | Large systems, legacy integration | ~$12,600 |
Fail-safe (F) versions add approximately 30-40%. Technology (T) versions available for advanced motion control. Prices indicative based on US market data plus Australian market factors.
Read out Siemens PLC overview here.
Want pricing? Contact us now directly.
Selection criteria
Memory sizing: Your existing S7-300 program size gives you a starting point, but S7-1500 code can be structured differently. Add 20-30% headroom for future expansion.
Communication interfaces: Count your PROFINET devices. If you have more than 64 devices or need device-level ring redundancy, you’ll need a CPU with multiple PROFINET interfaces or additional communication modules.
Safety requirements: If any part of your application needs safety-rated control (emergency stops, light curtains, safety gates), specify an F-CPU. You can mix safety and standard I/O on the same system.
Processing speed: The S7-1500 is significantly faster than S7-300. Unless you’re doing complex motion control or high-speed counting, even the 1511-1 PN has enough performance for most applications.
Memory card requirement
Unlike the S7-300, the S7-1500 requires a SIMATIC memory card. The CPU has no internal load memory. This is actually an advantage for maintenance:
- Program backup is as simple as swapping memory cards
- You can update programs without a programming device
- Firmware updates are card-based
You’ll need to size the memory card based on your program size plus overhead for data logging if you’re using that feature.
Migration considerations and common pitfalls
After helping multiple sites through S7-300 to S7-1500 migrations, here are the issues that consistently catch people out.
Program conversion realities
Siemens provides migration tools in TIA Portal that convert STEP 7 projects. They work reasonably well for basic logic. Where they struggle:
- Communication blocks: PROFIBUS DP master blocks don’t directly translate to PROFINET. You’ll need to reconfigure device communication.
- Special function modules: If you used FM modules (high-speed counting, positioning, etc.), the functionality moves to technology objects in S7-1500. This requires re-engineering, not just conversion.
- Addressing: S7-1500 uses optimized block access by default. This breaks absolute addressing that some older programs relied on.
Plan for program validation time. Don’t assume a converted program will run correctly without testing.
I/O system migration
The ET 200M distributed I/O system used with S7-300 is also discontinued. The replacement is ET 200MP for S7-1500.
Key differences:
- ET 200MP uses different mounting and wiring
- Module types and part numbers are completely different
- Configuration is done in TIA Portal, not HW Config
If you have extensive distributed I/O, factor in hardware replacement costs, not just the CPU upgrade.
Power budgeting
The S7-1500 backplane power requirements are different from S7-300. You’ll need to:
- Calculate total power consumption of all modules
- Verify your power supply can deliver sufficient current on the backplane
- Potentially add bus extension power supplies for larger racks
Siemens provides the TIA Selection Tool for power budgeting. Use it. We’ve seen systems fail commissioning because the power supply was undersized for the backplane load.
Commissioning and testing
Migration isn’t just hardware and software. It’s also:
- Operator training: HMI screens will look different. Operators need familiarization time.
- Documentation updates: I/O lists, network diagrams, and as-built drawings need revision
- Spare parts strategy: New part numbers mean new spare parts stock
- Backup procedures: Memory card handling differs from S7-300 backup batteries
Plan for a commissioning period where both systems might need to run in parallel, or where production windows are limited for cutover.
The Endless Process Automation advantage
At Endless Process Automation, we’re not tied to any single vendor. We supply and support Siemens, Rockwell, Schneider Electric, and others. That matters for your migration because we can give you a straight answer about what fits your application, not just what we have on the shelf.
Vendor-neutral sourcing
Sometimes the S7-1500 is the right choice. Sometimes a Rockwell ControlLogix or Schneider M580 makes more sense depending on your existing infrastructure, engineer familiarity, and integration requirements. We’ll tell you which is which.
Queensland-based support
With locations in Narangba, Gladstone, and Mackay, we understand Australian industrial conditions. We know what IP ratings mean when you’re 50km from the coast in high humidity. We know what dust ingress looks like in mining applications. And we know the lead times that Australian sites actually face.
Technical engineering support
We’re engineers first, salespeople second. Our team has done the hard yards in the field before stepping into technical sales. When you call with a migration question, you’ll talk to someone who has actually programmed the hardware, not just read the brochure.
Stock availability and alternatives
If Siemens lead times blow out (and they sometimes do), we can suggest alternatives from other vendors or help you stage the migration to minimize production risk. We don’t just take orders. We help you engineer the solution.
Check out what we can supply here with Endless Process Automation.
Getting started with your S7-1500 migration
If you’re facing an S7-300 migration, here’s a practical roadmap:
- System audit: Document your current S7-300 configuration, I/O count, communication architecture, and program size
- Requirements review: Identify what’s changing in your process. Don’t just replicate the old system. Improve it.
- Hardware selection: Choose your CPU, I/O modules, and communication components using the TIA Selection Tool
- Program conversion: Use TIA Portal migration tools, then plan for manual validation and correction
- Commissioning plan: Schedule installation, testing, and cutover with appropriate production windows
- Documentation and training: Update drawings and train operators on the new system
The S7-1500 is a solid platform. It’s faster, more capable, and better connected than the S7-300 ever was. But migration is a project that needs proper planning. The deadline has passed. The question now is how quickly you can move without creating new problems.
Need technical advice on your S7-300 migration or help sourcing S7-1500 hardware in Queensland? Contact Endless Process Automation for a vendor-neutral quote today.
Frequently Asked Questions
Can I still get spare parts for my S7-300 after the October 2025 discontinuation?
Spare parts are available but in limited quantities and at significantly increased prices. Siemens P.M410 status means components are only supplied as spare parts, not for new installations or expansions. We recommend auditing your spare parts inventory and securing critical components now.
Do I need to replace my entire S7-300 system, or can I migrate incrementally?
Incremental migration is possible but complex. The S7-1500 and S7-300 use different I/O systems (ET 200MP vs ET 200M) and communication protocols. Most sites find it more practical to migrate complete process areas or machines rather than mixing systems. We can assess your specific architecture and recommend the best approach.
How long does a typical S7-300 to S7-1500 migration take?
Timeline depends on system complexity. A simple CPU swap with minimal I/O might take a few days. A complex system with extensive distributed I/O, safety functions, and HMI integration could take several weeks. Planning, procurement, and commissioning typically add 2-3 months to the actual installation work.
Can Endless Process Automation supply Siemens S7-1500 controllers in Australia?
Yes. We supply the full range of Siemens S7-1500 hardware including CPUs, I/O modules, and accessories. With Queensland locations in Narangba, Gladstone, and Mackay, we can provide local stock holding and technical support for your migration project.
Is the S7-1500 suitable for hazardous area applications in Australian mining and oil & gas?
Yes. The S7-1500 F-CPUs (fail-safe versions) meet SIL 3 / PLe safety requirements commonly needed in hazardous areas. The standard IP20 rating means the PLC must be installed in a suitable enclosure for your area classification. We’ve deployed S7-1500 systems in coal handling, water treatment, and process plants across Queensland.
What’s the difference between TIA Portal and the old STEP 7 software?
TIA Portal is Siemens’ unified engineering environment that replaces STEP 7 Classic. It integrates PLC programming, HMI development, drive configuration, and safety programming in one software package. For S7-1500, TIA Portal is mandatory. STEP 7 Classic cannot program S7-1500 hardware.
Should I consider alternatives to the Siemens S7-1500 for my migration?
It depends on your situation. If your site is heavily invested in Siemens infrastructure and your engineers know the platform, S7-1500 is usually the smoothest path. If you’re starting fresh or have mixed vendor environments, alternatives like Rockwell ControlLogix or Schneider M580 might be worth evaluating. At Endless Process Automation, we supply multiple brands and can give you a vendor-neutral recommendation based on your specific requirements.