TIA Portal

The InOut interface in Siemens TIA Portal is a powerful tool for memory management and program efficiency. Instead of copying data in and out of blocks like traditional Inputs and Outputs, InOut passes variables by reference… using a pointer behind the scenes. This approach saves memory, reduces execution time, and keeps your programs lean.

You can easily recognise InOut parameters in TIA Portal by the double arrow symbol, which shows that data flows both into and back out of a Function or Function Block. While this can be incredibly efficient when working with large data structures, it’s important to understand the potential drawbacks, such as issues with cross-referencing and project-wide searches.

If you’re learning Siemens TIA Portal and want to understand how InOut interfaces work, when to use them, and what pitfalls to avoid, this guide will walk you through the key points.

Working with virtual machines is no longer optional in automation development… it’s essential. By containerising PLC and SCADA systems, engineers can build robust environments that can be suspended, cloned, or rolled back without risking valuable work.

My setup typically runs two VMs in parallel: a PLCSIM Advanced Virtual PLC and a WinCC SCADA VM. Together, they replicate the full development cycle. Hardware configurations, OPC UA servers, Modbus profiles, trending, archiving, and alarms. All tested against a virtual PLC that behaves just like the real thing.

The beauty of this approach is portability: you can develop anywhere, with nothing more than your laptop, and still validate every communication protocol as if you were on-site. When paired with a VPN gateway, the environment becomes collaborative too, allowing teams to share resources and even work against the same virtual hardware remotely.

What really makes this powerful is simulation mapping. Every input, from digital signals to VSD feedback, can be simulated, meaning an entire project can be stress-tested before hardware is even powered on.

This article walks step by step through creating this environment in VirtualBox, from setting up PLCSIM Advanced and WinCC, to configuring network adaptors, managing certificates, and extending your setup over VPN. By the end, you’ll have a self-contained Siemens development lab, capable of full-scale testing without touching a single real PLC.