Overview
ISO/IEC 14776-331:2002 - Stream Commands (SSC) is the ISO part of the SCSI stream device command set. It defines command set extensions that enable application clients to communicate with SCSI devices that declare themselves as sequential-access (stream) devices or printer devices. Used together with ANSI INCITS 351-2001, this standard fully specifies the SCSI stream device class command set for tape drives, streaming devices and SCSI printers.
Keywords: ISO/IEC 14776-331, SCSI, SSC, Stream Commands, sequential-access devices, SCSI stream device class, SCSI tape, tape drive command set.
Key topics and requirements
- Command set extensions: Defines commands unique to stream devices and commands to manage their operation.
- Supported device models: Detailed models for sequential-access (tape/stream) devices and printer devices, including physical and logical elements.
- Command definitions: Comprehensive commands such as ERASE, FORMAT MEDIUM, LOAD/UNLOAD, LOCATE, READ, WRITE, REWIND, SPACE, VERIFY, READ POSITION and printer-specific commands (FORMAT, PRINT, SLEW AND PRINT, STOP PRINT, SYNCHRONIZE BUFFER).
- Device behavior and state: Progress indication, ready state transitions, tagged command queuing, data buffering and recovery (RECOVER BUFFERED DATA).
- Partitioning and media layout: Volume/partition models, track/serpentine/helical layouts and partitioning schemes for sequential media.
- Diagnostics and reporting: Mode pages, diagnostic pages, log pages, TapeAlert interface and defined status/sense keys for error reporting.
- Operational controls: Write protection handling, device reservations, informational exceptions control and parameters for data compression, density support and device configuration.
- Normative/informative annexes: Historical density codes, TapeAlert log parameter codes and bibliographic references.
Applications and who uses it
ISO/IEC 14776-331 is essential for:
- Storage device manufacturers (tape drive, streaming device, SCSI printer firmware developers) implementing standard SCSI command behavior.
- System integrators and OS/storage stack developers ensuring correct SCSI command handling and driver support.
- Test labs and validation engineers verifying compliance, error handling and TapeAlert reporting.
- Enterprise storage architects designing backup, archival and streaming solutions that rely on SCSI tape/stream devices.
Practical applications include tape backup systems, long-term archival storage, streaming data appliances and SCSI-attached printer devices.
Related standards
- ANSI INCITS 351-2001 - complements ISO/IEC 14776-331 to fully specify the SCSI stream device class.
- Other parts of ISO/IEC 14776 (SCSI family) for device transport, command protocols and device classes.