Hey there! I totally get your dilemma - choosing your first PLC can feel overwhelming when you're just starting out. Let me break this down for you in simple terms.
For your specific needs (3 servo axes + 20 I/O points), both PLCs can handle the job, but here's what you should consider:
1. Budget-wise: Mitsubishi FX5U tends to be more affordable upfront, especially when you factor in the software costs. Siemens TIA Portal software can be quite expensive for beginners.
2. Learning curve: Mitsubishi's GX Works3 software is often considered more beginner-friendly. Many find its ladder logic interface more intuitive, with a learning time of 1-3 months compared to Siemens' steeper curve.
3. Scalability: This is where Siemens shines. If you plan to work with larger systems in the future or in industries where Siemens dominates (like automotive), the S7-1200 offers better upward compatibility with the S7-1500 series.
4. Servo control: Both handle servo control well, but check compatibility with your specific servo drives - some brands work better with certain PLC ecosystems.
My recommendation? If you're on a tight budget and want to get started quickly, go with the Mitsubishi FX5U. It's more beginner-friendly and cost-effective. But if you're planning to grow into larger systems or work in Siemens-heavy industries, the S7-1200 might be worth the extra investment for its scalability.
What's your industry and where are you located? That might help narrow it down further!