Siemens has released TIA Portal V21 as the new major version of its engineering environment for PLCs, HMIs, drives and industrial networks. The release is significant, but not always for the reasons often repeated online. This article focuses only on features that are verifiable in official Siemens sources.

Overview of verified TIA Portal V21 features
TIA Portal V21 brings documented changes to STEP 7, Safety, WinCC Unified and user management.
TIA Portal (Totally Integrated Automation Portal) is Siemens' integrated environment for PLC, HMI, drive and network engineering. In V21, Siemens focuses on standardisation, IT/OT integration, traceable engineering workflows and higher availability on the HMI/SCADA side.

The main new features that are actually confirmed

1. Git-oriented workflows through SIMATIC SD, VCI and external tools

The most important STEP 7 change is not a fully embedded Git client inside the IDE. It is the extension of SIMATIC SD (SIMATIC Source Documents) and its integration into the Version Control Interface (VCI). In V21, Siemens extends SIMATIC SD support to FBD, SCL and mixed-language blocks, in addition to DBs, PLC data types and library types.

The practical benefit is that engineering objects can be exported in a text-based format that is much better suited to comparison, automation and versioning. Siemens explicitly states that this facilitates integration with version control systems such as Git, but the workflow still relies on file-system workspaces and external version control tools.

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Important correction: describing V21 as having "native Git support" in the same sense as a software IDE is misleading. The official documentation describes integration with Git through VCI, SIMATIC SD, workspace-based workflows and external comparison tools, not a complete built-in Git client with init/commit/push/pull requests inside TIA Portal.

2. Download while keeping actual values even after structural DB changes

One of the most concrete STEP 7 enhancements in V21 is the "Keep actual values" option during download even when structural changes have been made to data blocks, provided that strict conditions are met.

This feature is available for S7-1500 with firmware V4.1, with optimized-access DBs and only for supported data classes. It is not universal: for example it is not offered for array dimension changes, string length changes, data type changes or retentivity changes.

3. Engineering change tracking inside the project

TIA Portal V21 introduces logging of engineering changes. When the project is saved, the system records additions, modifications, deletions and compilation information in a comprehensive log. The log is stored in the project and links directly to the relevant elements.

This does not replace Git or a version control system, but it does improve local project traceability significantly.

4. STEP 7 Safety V21: real and specific improvements

The officially documented Safety changes are more specific than marketing summaries often suggest. Siemens lists:

  • Flexible F-Link extended from 100 to 1500 bytes of user data
  • PROFIsafe Base ID support for S7-1500 and S7-1200 G2
  • Extended Named Value Types support and know-how protection for typified F-blocks
  • New Openness functions for F-I/O parameters, offline F-signatures, and F-capability activation/deactivation
  • Consistent upload for S7-1200 G2 V4.1

These are the Safety changes that Siemens documents explicitly for V21. They matter more in practice than broad generic claims, because they affect real workflows around validation, signatures, data exchange and protected engineering.

5. Safety Validation Assistant and Test Suite updates

TIA Portal V21 also adds features in testing and validation:

  • the Safety Validation Assistant now supports Openness for all tasks except test execution
  • SIRIUS 3SK2 safety relays are supported as stand-alone evaluation devices
  • activation tests and test cases can be exported and imported via the TIA user interface
  • the tool is qualified as a T2 tool

In TIA Portal Test Suite V21, Siemens also introduces a new Edit Test Suite data role to protect tests and rules against unauthorized access.

6. S7-PLCSIM Advanced: V21 is tied to V8, not V7

A common mistake is to associate TIA Portal V21 with PLCSIM Advanced V7. Siemens sources for the V21 release point instead to S7-PLCSIM Advanced V8.0. The official V21 material ties that version mainly to support for the S7-1200 G2 family and to running application tests in the TIA Portal Test Suite.

So it is fair to say that V21 expands simulation and test possibilities, but it is not careful to claim specific capabilities such as "multi-CPU simulation on one PC with OPC UA and Profinet between instances" unless those exact points are backed by a direct Siemens source.

7. Central user management and S7-1200 G2 support

Among the engineering updates, Siemens highlights the User Management Component (UMC). In V21, the SIMATIC S7-1200 G2 CPU with firmware V4.1 can be connected to central user management, with possible integration into Microsoft Active Directory.

For regulated environments or organisations with multiple teams, this is a more concrete and measurable collaboration improvement than many generic claims about teamwork.

8. New hardware, OPC UA and web server features on CPU firmware V4.1

In the hardware configuration section, Siemens documents several new functions for S7-1500 / ET 200 CPUs with firmware V4.1:

  • higher configuration limits for OPC UA methods on the server and, in some cases, on the client side
  • updating OPC UA client security certificates using GDS Push
  • significantly expanded system web pages with Motion Control diagnostics, hardware status, safety administration and service data

For S7-1500R/H systems, V21 also documents hardware changes in RUN, meaning new PROFINET IO devices can be added and existing module parameters adapted without switching the redundant CPUs to STOP.

9. S7-1200 G2 is a real part of the V21 story

Another major element of the release is the integration of the new S7-1200 G2 family, with emphasis on security, motion, PROFINET and web server features. Siemens highlights, among other things:

  • Secure Boot, know-how protection and secure communication for PG/PC and HMI
  • two Ethernet connections on all CPU models
  • support for 31 PROFINET devices and RT/IRT-PROFINET communication
  • OPC UA server, system logging and support for central users on UMC
  • extended Motion Control and kinematics functions

This is one of the areas where V21 is more than a software refresh: it also accompanies a broader Siemens hardware platform update.

10. WinCC Unified: redundancy and Unified Data Hub

On the HMI/SCADA side, Siemens presents two major themes in V21:

  • redundant architectures for SCADA applications based on WinCC Unified
  • WinCC Unified Data Hub as a central archive for production data, messages and audit trails

These points appear both in Siemens' official press material and in the product documentation. A practical note matters, though: the WinCC Unified documentation also lists specific requirements and restrictions, including licensing constraints, supported device classes and some limitations when redundancy is used.

System requirements

Operating systemWindows 10 and Windows 11 64-bit; Windows Server 2022 Standard and Windows Server 2025 Standard (full installation) according to the official documentation
Minimum processorIntel Core i3-6100U, 2.30 GHz
Minimum RAM8 GB
Minimum disk space20 GB available according to the general requirements table; full product setups and realistic project work often require more
Minimum resolution1024 × 768

For small projects or test activities, the official minimums may be sufficient. In production environments, especially with multiple Siemens applications installed, simulation, Unified or larger projects, a more capable workstation is usually the more realistic choice.

Compatibility and migration

Compatibility in V21 needs more precision than simply saying "V19 and V20 migrate automatically". Siemens states that:

  • projects and libraries can be upgraded in V21 starting from V14
  • V13 and earlier projects and libraries must first be upgraded to V13 SP1/SP2 and then to a version before V21
  • migration of STEP 7 Classic, WinCC flexible, WinCC V7 and integrated projects is no longer directly supported in V21 and requires an intermediate step using the Migration Tool V20 and TIA Portal V20

So recent TIA projects can usually be upgraded relatively smoothly, while classic or much older projects require a more structured migration path.

Our take

TIA Portal V21 is an important release, but not because it suddenly turns TIA Portal into a conventional software IDE. Its most solid and verifiable strengths are:

  • the extension of SIMATIC SD and VCI for versionable, Git-friendly workflows
  • internal engineering change tracking
  • real improvements in STEP 7 Safety and the Safety Validation Assistant
  • support for S7-1200 G2, UMC and PLCSIM Advanced V8
  • new capabilities around WinCC Unified Redundancy and Unified Data Hub
  • additional functions for firmware V4.1 CPUs, especially around OPC UA, web server features and hardware changes in RUN on redundant systems

Overall, V21 is a meaningful release for teams that work daily with Siemens platforms. Its value lies less in marketing headlines and more in the concrete improvements to traceability, validation, user management, hardware support and high-availability HMI/SCADA architectures.

Evaluating a migration to TIA Portal V21?

Contact us if you want a practical assessment of which new features really matter in your case: versioning, testing, Safety, WinCC Unified or migration of existing projects.

Official resources and useful guidance