Introduction
Siemens is the most widely used PLC manufacturer in Europe and one of the global leaders in industrial automation. Within the SIMATIC family, the S7-1200 and S7-1500 are the most used in new projects. Both are programmed with TIA Portal, but have important differences that determine which to choose.
Siemens S7-1200: The mid-range PLC
The S7-1200 was launched in 2009 as a successor to the S7-200. It is a compact, modular mid-range PLC, ideal for:
- Individual machines or small-to-medium installations
- Applications with a tight budget
- Projects that don't require intensive processing
- First automation of manual processes
Key features of the S7-1200:
- Compact CPU with integrated I/O
- Cycle time: ~1ms per 1000 instructions
- Communications: Profinet, Modbus TCP/RTU, USS
- Up to 1024 digital and 256 analogue I/O
- Basic CPU price: ~€300-500
Siemens S7-1500: The high-performance PLC
The S7-1500, launched in 2013, is the high-end of the SIMATIC family. Designed for complex applications and demanding production environments:
- Complete production lines
- Advanced motion control
- Applications with many networked CPUs
- Plants with functional safety requirements (Safety)
- Projects with high data volumes and advanced diagnostics
Key features of the S7-1500:
- Cycle time: up to 10x faster than S7-1200
- Integrated display on the CPU for field diagnostics
- Communications: Profinet (IRT), Profibus, native OPC-UA
- Up to 32,768 I/O
- Safety, Compact, Distributed and Software Controller versions
- Basic CPU price: ~€800-2000
Comparison table
| Feature | S7-1200 | S7-1500 |
|---|---|---|
| Processing speed | Medium | High |
| Motion Control | Basic | Advanced |
| Native OPC-UA | No | Yes |
| Integrated Safety | No | Yes (F-CPU) |
| Diagnostic display | No | Yes |
| Price | Low | High |
When to choose each one?
Choose S7-1200 if:
- It's a standalone machine with relatively simple logic
- Budget is limited
- You don't need advanced Motion Control or Safety
- It's a small-to-medium project
Choose S7-1500 if:
- It's a complex production line or robotic cell
- You need high cycle speed or precise motion control
- The project requires Safety (SIL 2/3, PLe)
- You want native MES/ERP integration via OPC-UA
- You need advanced diagnostics and predictive maintenance
At Bluemation we program both platforms with TIA Portal and can help you choose the best option for your project.