I have been downloading data with Loggernet from CR1000s for a while now and have only recently noticed that some of the files it is supposed to be appending data to are missing older data. It looks like it may be associated with logger program updates and overwriting rather than appending data following an update, but it also appears to have happened in a few instances unrelated to program updates. Any suggestions?
If there are incompatibilities in the data file header and the new data to be written, LoggerNet will back up the file with a .backup extension and a unique number and then create a new file. You didn't mention what version of LoggerNet that you are using. LoggerNet 4.1 applies more liberal rules when deciding whether the headers are compatible.