I found this in the help file. It may yield some information that you may find useful:
The Device.Backup.Running Config activity will make a backup of a device's running configuration and compare it to the current config file on disk. If there are differences, the current config is moved to the "Dated Configs" folder and the filename is appended with the current date. The newly downloaded config then becomes the current config. An HTML "diff" report is created in the "Reports" folder and a copy is e-mailed to the nominated person.
How it works. Step by step:
1. A connection is made via SSH or telnet to the device
2. The "Show running configuration" (or similar) command is issued
3. The config is collected and stored on disk in a temporary file
4. A check is made to see if there is an existing config file on disk for this device
5. If not, the newly downloaded config is placed in the "Configs" folder as the current device backup
6. If a current config file is present, it is compared to the newly downloaded config
7. A text and HTML report is made of the differences (if any) and stored in the "Reports" folder
8. If differences are found, a copy of the difference report is sent via e-mail
9. The current config file is moved into the "Dated configs" folder and appended with the current date
10. The newly downloaded config file is put in the "Configs" folder and becomes the current device backup
For more information see "Setting up the activity."