Product manual

3.4.16 Send Diagnostic command (1D
H
)
When the drive receives this command, it performs diagnostic tests on
itself. In systems that support disconnection, the drive disconnects while
executing this command.
Bit
Byte
7 6 5 4 3 2 1 0
0 0 0 0 1 1 1 0 1
1 LUN = 0 0 0
Self
Test
Dev
OfL
Unit
OfL
2 0 0 0 0 0 0 0 0
3–4 (default) Parameter list length (00
H
)
5 0 0 0 0 0 0 Flag Link
Byte 1 When the
self test bit is 1, the drive performs the buffer RAM
diagnostics, which is the default self test. If the default self
test is requested, the parameter list length is 0 and no data
is transferred. If the self test passes successfully, the com-
mand terminates with a good status. If the self test fails, the
command terminates with a check condition status and the
sense key is hardware error.
The
Dev OfL (device off line) bit is not supported.
The
UnitOfL (unit off line) bit is not supported.
Bytes 3–4 The
parameter list length is always zero. This byte is not
supported.
60 ST3655 Family SCSI Drives Product Manual, Rev. A