Even thou the configuration is stored in the internal flash and the SD Card, you might want to make a backup of your configuration.
To do this, on the TDX and the TDH800, follow this short procedure (here its done i Microsoft Edge).:
1. Log into your headend. When logged in, you will be on the main panel.
2. Select the configuration, you want to backup, by clicking on it. Scroll down, to the bottom of the page and click 'Load from TDX'.
3. You will be asked, where to save the configuration file. Select a folder of your own choice.
You now have a local copy / backup, of the configuration. This can be repeated for all the configurations stored on the headend.