WinCCflexLogViewer is a lightweight and simple-to-use archive Data log Viewer / Analyzer.
It is compatible with archives created with the WinCC (TIA Portal) Panel or PC Runtime as well as with the WinCC flexible Panel or PC Runtime.
Supports CSV (*.csv, .txt) and SQLite (.rdb) Siemens data log formats.
Allows to export parsed log data to CSV file (for further analysis, printing e.g.), print selected curves.
The tool is a stand-alone GUI application developed in C# language and requires .Net Framework 3.5 or higher.
plc2k http://plc2k.com/wincc-flexible-tia-portal-archive-viewer
ZedGraph https://github.com/ZedGraph/ZedGraph