PLC Tags and the Hardware Address Space
June 1, 2026 — Article 6 of the Studying TIA Portal series. Why PLC tags should be treated as a readable hardware vocabulary, not the whole software architecture: I/Q/M/DB spaces, IO mapping, symbolic names, and clean ownership boundaries.
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.
Data Blocks — Why TIA Treats Data as First-Class Objects
June 1, 2026 — Article 5 of the Studying TIA Portal series. Why Data Blocks in TIA Portal are more than storage: global DBs, instance DBs, commissioning diagnostics, start values, retention, download discipline, and the ownership rules that keep shared data readable.
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.
Function Blocks vs Functions — Code, State, and the Instance
May 25, 2026 — Article 4 of the Studying TIA Portal series. The structural difference between Function Blocks (FB) and Functions (FC) — code that remembers vs code that forgets — and how the instance data block model carries state across calls. Includes a cross-platform comparison of how Siemens TIA Portal, Beckhoff TwinCAT 3, Codesys, and SIMATIC AX implement the same IEC 61131-3 split, plus a worked example of multi-instance FB design and the two Siemens download-without-reinitialization mechanisms (per-DB memory reserve since V12, V21 "Keep actual values" for S7-1500).
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.
Organization Blocks — TIA Portal's Execution Model
May 18, 2026 — Article 3 of the Studying TIA Portal series. A working engineer's tour of TIA Portal's execution model through Organization Blocks — OB1, OB100, cyclic and hardware interrupts, diagnostic OBs — including a cross-platform comparison of how Siemens, Beckhoff, Codesys, Rockwell, and SIMATIC AX handle the main scan cycle.
The Map Before the Territory — What TIA Portal Programs Are Actually Made Of
May 7, 2026 — Article 2 of the Studying TIA Portal series. A working engineer's map of the building blocks of a TIA Portal program — OBs, FBs, FCs, DBs, instances, PLC tags, and types — and what makes TIA's design choices distinctive compared with other PLC platforms.
Why I'm Writing a Structured TIA Portal Series — And What You'll Get Out of It
May 4, 2026 — Series kickoff — why I am writing a structured TIA Portal series, the gap between Siemens manuals and engineering judgment, and the five movements that organize the series.
