Whenever saving an RTUs configuration, also save the corresponding Application and Gui files. The most common problem encountered in uploading a saved configuration to an RTU is a mismatch between it and the Application and Gui files. This happens because the saved configuration is being uploaded into a different baseboard. This happens when a spare board is installed and the spare board does not have the same version of firmware as the original RTU. Every RTU that ships from the factory, ships with the newest released firmware so it is likely that different units will have different firmware versions installed and uploading only the config file may well result in a mismatch situation. However, if the configuration is always uploaded with the corresponding Application and Gui, there will never be an issue. Note: Any version of firmware may be bumped up or down as long as the three files (Config, App, GUI) are kept in sync. The exception to this is that C3413(586) and C3414(LX800) firmware are not interchangable. Of course, any configuration may be translated to a newer version using the Config Converter tool that is part of the firmware update zip file. This will certainly need to be used if the reason for putting an old configuration into a newer unit is to take advantage of a new feature available in the newer RTU firmware set.