Hello Andreas,
Even though, there is no log file with historic signal strength data stored locally on RUT955 devices, there are 2 ways to obtain this information for your device:
1- Using RMS :
If your device is registered to RMS, you can go to your Device detail page => Metrics => Dynamic Information, select only Signal strength, and click on the Export shart data button to download the Signal strength history of your device (Click here for image).
2- Create a custom log file :
Please follow these steps:
Now, the script will run every 5 minutes, and each time it runs, it will add a line with time and signal strength value (RSSI) to the signal strength log file (/etc/signal_strength.log), which you can download from your device when it's needed (using scp for example: https://wiki.teltonika-networks.com/view/Upload_%26_Download_Files_from_RutOS). To save space on your device, the script also checks the log file size and deletes old data to keep it under the 1MB limit (1048576 Bytes), and you can always adjust the script to suit your needs.
Note: Custom scripts are beyond the scope of our technical assistance, you might need to adjust it accordingly as this is only an example.
Best regards,
Ismail