Hi Bertin
In all fairness, I believe that I have given you enough information to solve status 96.
You really need to book yourself on a 5-day training course or spend LOTS of time reading manuals.
I will try to answer your last set of questions:
How the data is copied to the tapes:
Data is sent via the scsi or fibre cable to the tape drive. Data is written in 'tar' format to tape.
how to recognize tapes:
Your library has a barcode reader. Ensure that you have barcode labels on the tapes before you start doing backups.
how to restore them:
You don't restore tapes - you restore backup images. Part of the catalog information in NetBackup is the media id used for each backup. When you browse for backups, you specify the client name, select the backup date, and then select the files/folders that you want to restore. NetBackup will find the media id in the catalogs. If the tape is in the robot, it will automatically be mounted, positioned to the correct place on tape and the restore will start. If the tape is not in the robot, you will see a message that media id XXXXXXX is needed for the restore and that it needs to be put in the robot.