Why are my trends from the "HDLog to file" FBoxes not updated?

FAQ #101299

 

Symptom
When using the "HDLog to file" feature, on the first loading the logged trend, the trends are displayed correctly. But on a reload of the trends to display more recent trend curves, no refresh is done. The browser (running the Java Virtual Machine) only reads the cached memory (instead of re-reading the files on the PCD).

Reason
Theoretically the WebServer 2 (implemented on PCD3 and PCD2.M5 systems with FW 1.10.16 or later) supports caching by the JVM. But the new feature "HDLog to file" feature does not yet support chaching. If this feature is used, please disactivate the caching in JVM.

Solution
Please desactivate the caching feature of the JVM as described in FAQ 100708 when using the "HDLog to file" FBoxes and macros.