Default Auto Backup of Internal and external Storage

For my personal data and PC I use Acronis True Image. There I can shedule backups of different partitions of my pc to an external usb storage. i use windows 8.1.
Im looking for an app that when i plug my st via usb to the pc, it makes automatic a backup from the internal and external storage of the s3, but the backup shourd be automatic on the external usb drive.
is this possible?
i tried foldersync, but i get an connectioon failure when i share my external usb device in the network.
any help?