The IDD does not reply to the SCSI bus for up to 2 seconds after the initial self-diagnostics is started. After that, the IDD can accept the I/O operation request correctly, but the received command, except the executable commands under the not ready state (such as INQUIRY, START/STOP UNIT), is terminated with the CHECK CONDITION status (NOT READY [=2]/logical unit not ready [=04-00]) during the interval from the spindle motor becomes stable to the IDD becomes ready. The executable command under the not ready state is executed in parallel with the initial self-diagnostics, or is queued by the command queuing feature and is executed after completion of the initial self-diagnostics. When the command that comes under the exception condition of the command queuing is issued at that time, the IDD posts the BUSY status for the command. When the error is detected during the initial self-diagnostics, the CHECK CONDITION status is posted for all commands that were stacked during the initial self-diagnostics. For the command execution condition, refer to Section 1.4 and Subsection 1.7.4 in SCSI Logical Interface Specifications.
(2)Online self-diagnostics (SEND DIAGNOSTIC command)
The INIT can make the IDD execute self-diagnostics by issuing the SEND DIAGNOSTIC command.
The INIT specifies the execution of self-diagnostics by setting 1 for the SelfTest bit on the CDB in the SEND DIAGNOSTIC command and specifies the test contents with the UnitOfl bit.
When the UnitOfl bit on the CDB is set to 0, the IDD executes the hardware function test only once. When UnitOfl bit is set to 1, the IDD executes the hardware function test, seek (positioning) test, and data write/read test for the Internal test space only once.
a.Error recovery during self-diagnostics
During the self-diagnostics specified by the SEND DIAGNOSTIC command, when the recoverable error is detected during the seek or the write/read test, the IDD performs the error recovery according to the MODE SELECT parameter value (read/write error recovery parameter, additional error recovery parameter) which the INIT specifies at the time of issuing the SEND DIAGNOSTIC command.
PER | Operation of self-diagnostics |
0The self-diagnostics continues when the error is recovered. The self- diagnostics terminates normally so far as the unrecoverable error is not detected.
1The self-diagnostics continues when the error is recovered. If the unrecoverable error is not detected, the consecutive tests are executed till last test but the self-diagnostics terminates with error. The error information indicates that of the last recovered error.
b.Reporting result of self-diagnostics and error indication
When all specified self-diagnostics terminate normally, the IDD posts the GOOD status for the SEND DIAGNOSTIC command.
