Error Handling in SIMATIC AX - TRY/CATCH from a TIA Portal Lens
June 1, 2026 — Article 16 of the Studying SIMATIC AX series. The current tested SIMATIC AX ST compiler rejects general TRY/CATCH, so expected PLC fault conditions still need deterministic guard/report/recover logic, safe defaults, and alarm/status reporting.
Configuration, Tasks, and Programs — The AX Scan Cycle
May 27, 2026 — Article 15 of the Studying SIMATIC AX series. The AX scan cycle explained from the configuration.st file — what CONFIGURATION, TASK, and PROGRAM actually mean, how task priorities and interruption work, the declarative TASK→PROGRAM binding pattern versus calling OBs from OB1, multi-task patterns including a measured struct atomicity test on PLCSIM Advanced V8.0, and the complete mapping back to TIA Portal architecture.
The apax CLI — Every Command Worth Knowing
May 19, 2026 — Article 14 of the Studying SIMATIC AX series. A walk through every apax command worth knowing — create, install, build, test, dm, and the supporting commands around the edges. With honest notes on the rough edges of the Device Manager subsystem from hands-on use of apax CLI v4.3.0.
Variables and the Type System in SIMATIC AX
May 11, 2026 — How SIMATIC AX organizes variables and types for TIA Portal engineers — VAR_INPUT/VAR_OUTPUT/VAR sections, VAR_GLOBAL and VAR_EXTERNAL contracts, STRUCT and ENUM patterns, typed literals, and the AT keyword for direct addresses. A practical mapping from TIA Portal mental models to AX text.
TempController on a Real Screen — End-to-End AX + WinCC UE Demo
May 6, 2026 — Hands-on walkthrough of connecting a SIMATIC AX function block to a WinCC Unified Elements screen over OPC UA. Pragmas, YAML tags, the V:1$DA$ address quirk, and the full apax build → run loop — with PLCSIM Advanced and Unified Runtime, no TIA Portal GUI involved.
WinCC Unified Elements — Code-Based HMI for TIA Portal Engineers
April 30, 2026 — WinCC Unified Elements explained for TIA Portal engineers — how the new code-based HMI environment works, how it pairs with SIMATIC AX over OPC UA, and what is missing today.
CLASS vs FUNCTION_BLOCK in SIMATIC AX — Explained for TIA Portal Engineers
April 8, 2026 — A deep dive into the two main building blocks of SIMATIC AX — FUNCTION_BLOCK and CLASS. What each one supports, when to use which, and how they fit together in real projects. Written for TIA Portal engineers who already know function blocks.
What Is the Future PLC Programming Tool of Siemens: Simatic AX or TIA Portal?
March 31, 2026 — The question is no longer what tool is more convenient for humans. The question is what tool is more convenient for AI agents. My take on Simatic AX vs TIA Portal.
How to Write Unit Tests in SIMATIC AX — A Step-by-Step Guide for TIA Portal Engineers
March 27, 2026 — A hands-on guide to writing unit tests in SIMATIC AX using AxUnit. Walks through the anatomy of a test file, the reset pattern, assert methods, running tests, and what to test versus what to leave for commissioning.
Unit Testing in SIMATIC AX — I Proved My PLC Code Works Without a PLC
March 25, 2026 — What unit testing is, why TIA Portal engineers should care, and how SIMATIC AX's built-in AxUnit framework lets you verify PLC code automatically — no hardware needed.
SIMATIC AX Project Structure Explained for TIA Portal Engineers
March 17, 2026 — A complete mapping of TIA Portal concepts — OBs, FBs, FCs, DBs, tag tables — to their SIMATIC AX equivalents. The reference guide for PLC programmers making the switch.
Namespaces in SIMATIC AX Explained for TIA Portal Engineers
March 17, 2026 — A deep dive into namespaces — what they are, why TIA Portal does not have them, how to use them in AX, and the mistakes you will make if you think about them with TIA Portal logic.
Two Types of SIMATIC AX Projects — Full AX vs TIA Portal Hybrid
March 11, 2026 — When you run apax create, you face a choice between two fundamentally different project types — full AX engineering or a hybrid with TIA Portal. Here is how they differ and which one to start with.
You Don't Need AX Code IDE — SIMATIC AX Runs From Any VS Code Workspace
March 10, 2026 — SIMATIC AX is fully CLI-driven. You can run apax commands from any terminal inside your normal VS Code workspace — no AX Code IDE required.
Siemens Just Filled the Biggest Gap in Simatic AX — HMI Design
March 4, 2026 — WinCC Unified Elements brings code-based HMI design to the Simatic AX family — visual and YAML-based screen design in VS Code, with native Git support.
