LOGO! 8 vs LOGO! 9 — Real, Practical Differences
The transition from LOGO! 8 to LOGO! 9 is more significant than it appears at first glance. While the LOGO! series has always been known for compact automation and simplicity, the ninth generation pushes the platform into a new category. It brings features that previously required a mid‑range PLC, making it far more capable for modern industrial and building automation tasks.
Display and Diagnostics
LOGO! 9 introduces a larger, brighter, and higher‑contrast display. The improved viewing angles and clearer menu structure make on‑site diagnostics noticeably easier. For technicians working in poorly lit electrical rooms or industrial environments, this is a practical improvement that saves time and reduces errors.
Increased Program Capacity
One of the most important upgrades is the expanded program size. LOGO! 9 supports more function blocks, more networks, and more complex logic structures. This allows engineers to build larger automation tasks without needing to switch to a higher‑end PLC. Applications that previously pushed LOGO! 8 to its limits now run comfortably on LOGO! 9.
Enhanced Communication
Communication capabilities have been significantly improved. LOGO! 9 offers faster Ethernet performance, more stable Modbus TCP integration, and better compatibility with cloud platforms. The internal web server has also been updated, providing a cleaner interface and more responsive control. These changes make LOGO! 9 far more suitable for Industry 4.0 and IoT‑driven installations.
Floating‑Point Support
This is one of the most anticipated features. LOGO! 9 finally supports floating‑point (real number) calculations. This unlocks a wide range of new applications:
temperature control
analog sensor processing
energy monitoring
proportional control
mathematical calculations that were impossible with integer‑only logic
For many users, this single feature alone justifies upgrading.
New Expansion Modules
Siemens has introduced new I/O modules optimized for LOGO! 9. These include faster analog inputs, improved measurement accuracy, and updated communication modules. The system remains modular and backward‑compatible, but the new modules offer better performance for demanding applications.
Improved Security
Cybersecurity is becoming essential even for small automation systems. LOGO! 9 includes updated certificates, improved project protection, and more secure communication handling. This makes it safer to integrate the device into networks that connect to SCADA, BMS, or cloud services.
Why LOGO! 9 Matters in 2026
The LOGO! series has always been popular among electricians, small integrators, and engineers who need reliable automation without the complexity of a full PLC. LOGO! 9 keeps this philosophy but modernizes it for today’s requirements.
The combination of floating‑point support, better communication, and increased program capacity means LOGO! 9 can now handle:
HVAC control
energy management
small industrial machines
smart building automation
remote monitoring
IoT‑connected systems
It is still simple, still compact, still affordable — but now much more capable.