> What do I need to do now to ensure that datalog files will not become > obsolete with changes in the future? >
This is a problem with all binary formats and most textual ones too. There is no simple solution, but the key is to place versioning or descriptive information about the contents at a known location in the file, then never change that. As an example, just one integer at the front of your data header, can be used to switch on to carry out the appropriate reads or unpacking to get back the data that was saved. Of course five years from now, you will likely have in the same switch, code to compute or store default values for other fields that the rest of the application expects, but that weren't saved. So, like the binary storage format of VIs, it is possible to add many features and be able to load and save all the formats. It is easier to load the old and only save a few of the newest. Coming up with a universal storage format is very difficult. Greg McKaskle
