Quantum 1200 Series DAT Autochanger Podręcznik Użytkownika Pobierz pdf (Strona 45)

SDLT 600 SCSI Interface Guide Chapter 4: SCSI Commands

81-81200-02 REV A01 January 2005 4-3

4.1.1 Status and Error Reporting

SCSI message-level errors are communicated by messages that are defined specifically for that

purpose (for example, MESSAGE PARITY ERROR, MESSAGE REJECT). Message-level errors are

also handled by drive-managed retries. Refer to Chapter 3, “SCSI Messages” for more detailed

message-handling information.

SCSI command-level errors are communicated by a status code that the drive returns during the

STATUS phase. This phase occurs at the end of each command unless one of the following events

terminates the command:

• ABORT TASK SET message

• TARGET RESET message

• Reset condition

• Unexpected disconnect.

The status code is contained in bits 1 through 5 of the status byte. Bits 0, 6, and 7 are reserved.

Table 4-2 describes the status codes the drive returns.

WRITE BUFFER 3Bh Page 4-249

WRITE FILEMARKS 10h Page 4-252

1. SA = Service Action

NOTES:1The SDLT tape drive does not act as an initiator on the SCSI

bus. Therefore, the drive does not 1) generate unsolicited

interrupts to the host, 2) initiate its own SCSI commands, or

3) assert bus RESET.

2 The RECEIVE DIAGNOSTIC RESULTS and SEND

DIAGNOSTIC commands implement vendor-specific pages

to test the drive during the manufacturing process. Quantum

recommends that initiators specify only the non-page format

variants of these commands (PF=0) for all pages except page

40h.

Table 4-1. SCSI Commands Supported by SDLT Tape Drives (Continued)

Command Operation Code Subsection

1 2 ... 40 41 42 43 44 45 46 47 48 49 50 ... 293 294

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Quantum 1200 Series DAT Autochanger Podręcznik Użytkownika Strona 45