I am also trying to convert a .plw file into something that excel or origin can read. I have tried opening it in the picolog program (version 5.13.0), but it doesn't seem to work. Whilst the file does open and report how many samples it has, there is no further data displayed, a graph is blank and a speadsheet is similarly empty.
Apparently this did not happen on the previous version we were running, but that was before my time here.
Any help or suggestions vastly appreciated.