High-resolution pre/post-fault data logging for industrial rotating machinery : a TwinCAT-based performance optimization study

Abstract

This thesis describes the restoration and optimization of a pre/post-fault data logger for the Aurelia A400 gas turbine, a 400 kW industrial machine controlled by a Beckhoff TwinCAT3 PLC application. The logger had been carried over to a redesigned object-oriented software environment without proper adaptation, resulting in repeated cycle time overruns that prevented reliable operation.

The work identifies three root causes: excessive load from string operations and file writing in the main PLC task, a fixed-row chunk writing strategy with no buffer capacity awareness, and unnecessarily high floating-point precision applied uniformly to all logged variables. Each issue is resolved separately. The logger is moved to a dedicated task on an isolated CPU core, the fixed chunk writer is replaced with a buffer-aware mechanism that estimates row size before writing, and automatic type detection with configurable decimal precision is implemented.