What is SIMATIC?
SIMATIC is the Siemens product family for industrial automation, covering PLCs, distributed I/O, HMI panels, SCADA and DCS software and the TIA Portal engineering environment, which together form one integrated control platform. The name combines “Siemens” and “Automatik” and was registered as a trademark as early as 1958. SIMATIC is one of the most widely used automation platforms in the world, running production lines, water treatment plants, chemical sites, power stations, pharmaceutical facilities and machine building. For OT and IT teams alike, SIMATIC is therefore often the first system they meet in OT convergence projects.
🕰️ How has SIMATIC evolved?
SIMATIC has more than sixty years of history, from hard-wired transistor logic to virtual controllers:
| Year | Milestone |
|---|---|
| 1958 | SIMATIC trademark registered with the German patent office |
| 1959 | SIMATIC G: hard-wired logic built with germanium transistors |
| 1973 | SIMATIC S3: the first microprocessor-based SIMATIC system |
| 1979 | SIMATIC S5 with the STEP 5 programming software, supplied until around 2000 |
| 1994 | SIMATIC S7 with the S7-200, S7-300 and S7-400 families |
| 1996 | Totally Integrated Automation (TIA) concept: one coherent portfolio |
| 2009 | S7-1200 as the successor to the S7-200 |
| 2010 | TIA Portal engineering platform presented at SPS/IPC/Drives; V11 (2011) is the first generally available version |
| 2012 | S7-1500 presented at the SPS fair in Nuremberg |
| 2019 | WinCC Unified (with TIA Portal V16) and the web-based PCS neo |
| 2023 | S7-1500V: the first virtual SIMATIC controller, running as an app on Industrial Edge |
| 2025 | TIA Portal V21 with Git-compatible export and redundant WinCC Unified servers |
The common thread is integration: hardware, network, visualisation and safety share one data model and one engineering tool. That speeds up engineering, but it also makes a plant strongly dependent on a single vendor.
🧱 What are the components of SIMATIC?
SIMATIC is not a single product but a coherent portfolio. The main building blocks:
| Component | Examples | Function |
|---|---|---|
| Controllers | S7-1200, S7-1500, S7-1500R/H, S7-300, S7-400 | Real-time control of machines and processes |
| Distributed I/O | ET 200SP, ET 200MP, ET 200M, ET 200iSP | Connecting sensors and actuators via ProfiNET or Profibus |
| Logic modules | LOGO! | Simple control tasks without a full PLC |
| HMI | Basic Panels, Comfort Panels, Unified Comfort Panels | Operation at the machine |
| SCADA | WinCC (V7/V8), WinCC Unified, WinCC OA | Central visualisation, alarming and trends |
| Process control | PCS 7, PCS neo | DCS for the process industry |
| Engineering | TIA Portal with STEP 7, WinCC, PLCSIM | Programming, configuration and simulation |
| Software PLC | S7-1500 Software Controller, S7-1500V | Control on an industrial PC or as a soft PLC |
Note that not everything runs in TIA Portal. PCS 7 is still engineered in the classic SIMATIC Manager (STEP 7 V5.x), and so are many older S7-300/S7-400 projects.
⚙️ Which SIMATIC controllers are there?
The PLC families differ in performance, lifecycle stage and security capabilities:
- S7-1200 (and S7-1200 G2 since late 2024) - compact controller for small machines and installations
- S7-1500 - the current standard for medium-sized and large applications, with variants for motion control (T/TF), redundancy (R/H) and safety (F)
- S7-300 - for years the workhorse of industry; the S7-300 and ET 200M have been in phase-out since 1 October 2023, with the end of standard delivery on 1 October 2025 and spare parts until around 2033
- S7-400 / S7-410 - for large process installations and as the controller under PCS 7
Programming is done in STEP 7 using LAD (ladder), FBD (Function Block Diagram), SCL (Structured Text), STL (statement list) and GRAPH (an SFC variant), depending on the CPU family. The languages largely follow IEC 61131-3, with Siemens-specific extensions.
🌐 How does SIMATIC communicate?
SIMATIC uses a mix of open standards and Siemens’ own protocols:
| Protocol | Role within SIMATIC |
|---|---|
| ProfiNET RT / IRT | Real-time Industrial Ethernet to I/O and drives; IRT for synchronised motion control with very low jitter |
| Profibus DP / PA | Classic fieldbus, still common in existing plants and process instrumentation |
| S7 Comm | Classic protocol of the S7-300/S7-400 on TCP port 102, without authentication or encryption |
| S7 Comm Plus | Protocol of the S7-1200/S7-1500, with TLS 1.3 since TIA Portal V17 |
| OPC UA | Built-in server and client in the S7-1500, for links to MES, historians and IT |
| TSN | Future converged Ethernet layer for ProfiNET |
In motion control and high-speed production, low latency and minimal jitter matter most: a delayed frame can directly affect synchronisation, product quality and machine safety. Redundant ring topologies keep communication running when a cable breaks.
🛡️ How does Safety Integrated work?
Safety Integrated is the Siemens concept in which functional safety runs in the same controller and network as standard control, instead of in a separate relay cabinet. It is therefore not a separate controller series but a combination of:
- F-CPUs - fail-safe PLCs such as the S7-1500F, suitable up to SIL 3 under IEC 61508 and IEC 62061 and PL e under ISO 13849 (ISO 13849-1)
- F-I/O - safety inputs and outputs in the ET 200 families
- PROFIsafe - a safety protocol on top of ProfiNET and Profibus
- STEP 7 Safety - engineering of safety programs in TIA Portal, with signatures that make changes visible
In the process industry, PCS 7 with F/FH systems provides the basis for safety functions according to IEC 61511.
🔐 How do you secure a SIMATIC environment?
SIMATIC systems are a well-known target. Stuxnet, discovered in 2010, spread partly through STEP 7 project files and WinCC, replaced a STEP 7 communication library and so reprogrammed S7-300 and S7-400 controllers unnoticed. Ransomware regularly hits the Windows-based engineering and SCADA stations. Typical threats are unauthorised engineering access, manipulation of PLC logic, protocol abuse, lateral movement and supply-chain attacks.
Siemens itself follows a defence-in-depth model aligned with IEC 62443. Siemens ProductCERT publishes security advisories for validated vulnerabilities, usually on a fixed monthly patch day. Key measures:
| Measure | How it applies in SIMATIC |
|---|---|
| Network Segmentation | Controllers in their own zones following the Zones and Conduits Model and the Purdue Model |
| Industrial Firewall | Allow only necessary traffic to port 102, ProfiNET and OPC UA |
| CPU access levels | Full, read, HMI or no access without a password; keep PUT/GET disabled |
| Secure PG/HMI communication | Enable TLS and PLC certificates (TIA Portal V17 or later) |
| MFA and Jump Server | Remote access to engineering stations only through a controlled path |
| Application Whitelisting | Only approved software on engineering and SCADA PCs |
| Patch Management | Update firmware and TIA Portal after testing, based on ProductCERT advisories |
| Monitoring | Passive monitoring of S7 traffic, including downloads and STOP commands |
| Backup | Store projects and PLC programs encrypted and offline |
Combine this with a zero-trust approach to remote access, and use NIST SP 800-82 and ISO 27001 for the wider security policy.
🧭 How do you handle migration and lifecycle?
SIMATIC installations often run for twenty to thirty years, while firmware, Windows and engineering software age much faster. Lifecycle Management is therefore a core part of operations. A practical approach for, say, an S7-300 installation:
- Take inventory - record the CPU type, firmware version, I/O, network links and software versions for each installation
- Determine the lifecycle stage - check the Siemens lifecycle status; for the S7-300 and ET 200M, the spare parts period runs until around 2033
- Choose a migration path - replace the CPU with an S7-1500 and if needed keep the existing S7-300 I/O for a while in an ET 200M with a ProfiNET interface module, or migrate in one step
- Convert and test - migrate the project to TIA Portal, test with PLCSIM or a digital twin, and validate through FAT and SAT with a rollback scenario
- Secure from day one - enable access levels, TLS communication and segmentation during the changeover, so the new installation does not inherit the weaknesses of the old one
In regulated environments such as pharmaceuticals, GMP requirements and GAMP validation apply. In the Netherlands, legislation also plays a role: the Cybersecurity Act (Cyberbeveiligingswet, in force since 15 August 2026, the Dutch implementation of NIS2) requires essential and important entities to demonstrate risk management, and the Cyber Resilience Act obliges manufacturers to report actively exploited vulnerabilities from 11 September 2026, with full application from 11 December 2027.
🏭 What does SIMATIC look like in practice?
A Dutch water treatment plant illustrates a typical architecture:
| Level | Component | Communication |
|---|---|---|
| Level 0 | Sensors, pumps, valves | Wiring and ProfiNET |
| Level 1 | S7-1500 PLCs with ET 200SP I/O | ProfiNET in a redundant ring |
| Level 2 | WinCC SCADA and operator stations | S7 Comm Plus, preferably with TLS |
| Level 3 | Historian and MES | OPC UA |
| Level 3.5 | IDMZ with firewalls | Controlled data transfer |
| Level 4 | Enterprise IT and ERP | API and SQL |
Known risks in such an environment are legacy PLCs, remote vendor access, insufficient segmentation, unpatched engineering stations and shared accounts.
☁️ What role does SIMATIC play in Industry 4.0?
SIMATIC is shifting from hardware-bound control to software-defined automation within Industry 4.0 and the Industrial Internet of Things. With SIMATIC Industrial Edge, apps for analytics, AI models and predictive maintenance run next to the machine, in line with edge computing. The S7-1500V brings the PLC itself to those edge servers as a virtual instance, and the former cloud platform MindSphere has evolved into Insights Hub. This delivers scalability and central updates, but it also enlarges the attack surface and the dependency on IT infrastructure. Cybersecurity and alignment according to ISA-95 therefore become as important as control itself.
❓ Frequently asked questions
What does the name SIMATIC stand for?
SIMATIC is a combination of “Siemens” and “Automatik”, the German word for automation. Siemens registered the name as a trademark in 1958 and has used it ever since for its industrial automation products, from the first transistor controls to today’s S7-1500.
What is the difference between SIMATIC and TIA Portal?
SIMATIC is the Siemens product family of controllers, I/O, HMI and software. TIA Portal is the engineering software you use to program and configure most modern SIMATIC components, such as the S7-1200, S7-1500 and WinCC Unified panels.
Is the SIMATIC S7-300 still supported?
The SIMATIC S7-300 and ET 200M have been in phase-out since 1 October 2023, and standard delivery ended on 1 October 2025. According to Siemens, spare parts remain available until around 2033, but the S7-1500 is the successor for new projects and migrations.
Is SIMATIC secure enough for critical infrastructure?
Modern SIMATIC controllers such as the S7-1500 offer access levels, TLS-encrypted communication and signed firmware. The real security of a SIMATIC installation, however, depends on configuration, segmentation, patching and monitoring in line with IEC 62443, and on replacing outdated S7-300 and S7-400 systems in time.
Which programming languages does SIMATIC use?
SIMATIC controllers are programmed in STEP 7 with LAD (ladder), FBD, SCL (Structured Text), STL and GRAPH. Which languages are available depends on the CPU family, and the languages largely follow IEC 61131-3.
What is a virtual SIMATIC PLC?
The SIMATIC S7-1500V, presented in 2023, is a virtual PLC that runs the functions of an S7-1500 in software on an Industrial Edge server. It is compatible with TIA Portal projects and managed centrally, while the I/O stays physically in the plant.
📌 In summary
Since 1958, SIMATIC has been the Siemens automation brand, covering PLCs, I/O, HMI, SCADA, DCS and engineering software in one coherent portfolio. The move from S7-300/S7-400 to S7-1500, TLS-secured communication and software-defined control makes the platform more modern, but it also calls for tight lifecycle and security management.
SIMATIC is the integrated automation platform from Siemens: one ecosystem of controllers, networks, visualisation and safety that only stays secure with timely migration, segmentation and management in line with IEC 62443.