When a data set is opened for OUTPUT, file sequence 1, DISP=NEW, OPEN processing will be enhanced to recognize the data class recording technology specification and will explicitly direct the TS1140 to record in the appropriate recording format. By default, the TS1140 will record in the non-encrypted up-level format EFMT4 unless explicitly changed to record in another format. OPEN processing will always send down the recording format specified in data class, and if a recording format is not explicitly specified, EFMT4 will be used.

When writing from BOT (file sequence 1, DISP=OLD.SHR (for volume reuse), because this processing does not go through the data class ACS routine, Open processing will determine whether encryption had previously been used and will ensure that the next usage of the volume is consistent with past usage. If the previous usage of the volume used encryption, OPEN will explicitly set the new encryption format (EEFMT4). OPEN will also obtain and pass the volume’s existing key management-related information to the drive (key label and encoding mechanism). If encryption was not used, the default recording format (EFMT4) will be used. This behavior is consistent with past 3592 generation drives.