Key Takeaway
Siemens PLCs are programmed using TIA Portal (Totally Integrated Automation Portal) and SIMATIC Step 7 software. TIA Portal is the modern integrated environment covering S7-1200, S7-1500, and newer S7-300/S7-400 models. It allows programming, configuration, HMI design, and diagnostics within one unified platform. For older systems like S7-300 and S7-400, Step 7 Classic (SIMATIC Manager) was originally used. Additionally, the LOGO! Soft Comfort software is used for LOGO! PLCs (small-scale automation). The choice of software depends on PLC model and project scope. TIA Portal is preferred today for its intuitive interface, centralized project management, hardware configuration, simulation, and extensive library management features, making Siemens programming faster and more productive.
Introduction to TIA Portal and STEP 7
If you’re stepping into the world of Siemens PLCs, the very first thing you must know is this — TIA Portal and STEP 7 are your best friends. These two tools are the backbone of Siemens automation programming. TIA Portal, short for Totally Integrated Automation Portal, is an all-in-one software framework. It combines engineering and diagnostics tools into one simple platform.
Now, what about STEP 7? This is the specific programming tool inside TIA Portal that’s used to configure and program Siemens PLCs. STEP 7 supports both the older classic platforms and the modern TIA-based ones. If you’re working with Siemens S7-1200 or S7-1500 PLCs, you’ll be using TIA Portal STEP 7 most of the time.
Here’s what makes it exciting — everything from hardware configuration, network setup, programming (LAD, FBD, STL), to simulation and diagnostics happens in a single interface. That means less switching between tools and more time focused on building powerful automation logic.
Compatibility with Siemens PLC Families
Siemens has a broad range of PLC families — from the S7-200, S7-300, S7-400, to the latest S7-1200 and S7-1500 series. So, which software supports what?
Let’s break it down:
S7-200: Uses STEP 7 MicroWin, a lightweight tool, ideal for micro-automation.
S7-300/S7-400: Uses STEP 7 v5.x (Classic). Still used in many legacy systems.
S7-1200/S7-1500: Best programmed with TIA Portal + STEP 7 (modern version).
TIA Portal provides backward compatibility, so you can manage both old and new Siemens PLCs from one platform. This is especially helpful for industries with mixed hardware generations.
And here’s the real game-changer — with each software version update, Siemens adds better compatibility layers, making migrations easier and smoother for integrators and plant engineers.
Engineering Features and Interface Design
Let’s talk usability. TIA Portal was clearly designed by engineers, for engineers. The interface is intuitive — drag and drop, tabbed navigation, easy access to instructions and tag lists. It feels less like coding and more like building.
You get all major programming languages:
Ladder Logic (LAD)
Function Block Diagram (FBD)
Structured Text (ST)
Statement List (STL)
It also includes smart diagnostics, error checking, and real-time feedback. TIA Portal even recommends blocks or settings based on your hardware configuration. That’s like having an assistant on your screen.
Another gem? Global tag databases, reusable code blocks, and user-defined libraries. These features let you build once and use many times — speeding up development and reducing errors.
Integration with HMI, SCADA, and Drives
This is where TIA Portal really stands out — it’s not just for PLCs. It’s a unified environment that includes HMI (Human Machine Interface), SCADA (Supervisory Control and Data Acquisition), and drive integration.
With TIA Portal, you can:
Configure and design HMI screens directly in the same project.
Link tags across PLCs and HMIs seamlessly.
Integrate Siemens SINAMICS drives for motion control without needing separate tools.
This level of integration means faster commissioning, fewer mistakes, and better visibility across systems. It also supports third-party device connectivity via standard protocols like Profinet, Profibus, and OPC UA.
So if you’re managing a full automation line — PLC, HMI, drives, network diagnostics — TIA Portal is your one-stop platform.
Licensing and Version Management
Let’s address a common question — how is TIA Portal licensed? Siemens offers tiered licensing:
Basic (for S7-1200 + basic HMI)
Professional (for S7-300, S7-400, S7-1500, SCADA, drives)
Licenses can be node-locked or floating, and upgrades are smooth. Siemens provides a “TIA Selection Tool” to choose exactly what licenses you need based on your hardware setup.
Also, each project is saved with a specific version. That’s where version management becomes important. TIA Portal supports parallel installations of different versions on the same system. You can even migrate projects forward (with caution) when upgrading software.
This is especially helpful when supporting older systems in the field while developing new ones using the latest version. Siemens understands that factories can’t always upgrade overnight, and they’ve built flexibility into their licensing and software support.
Conclusion
Siemens PLCs use a powerful suite of tools — TIA Portal and STEP 7 — that combine engineering flexibility with industrial reliability. From small S7-1200 systems to complex S7-1500 networks with HMIs and drives, everything runs through a unified software environment.
For new engineers, the learning curve is real. But once you get the hang of it, TIA Portal becomes your command center — a trusted companion for every automation challenge. It’s not just about writing code — it’s about designing smart, scalable, and future-ready systems.
Start small, get your hands dirty, and you’ll soon appreciate why Siemens software has become the global standard for industrial automation programming.