User's Manual

DLT4000 SCSI Interface
DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem 8-115
8.4.21 SEND DIAGNOSTIC (1Dh)
Bit
7 6 5 4 3 2 1 0
0 Operation Code (1Dh)
1 Logical Unit Number PF Rsvd Selftst
Dev OfL UnitOFl
2 Reserved
Byte 3 (MSB)
4 Parameter List Length (LSB)
5 Unused Reserved Flag Link
Figure 8-73 SEND DIAGNOSTIC CDB
SEND DIAGNOSTIC tells the drive to perform its diagnostic tests.
The Page Format field is not supported and must be zero.
Two separate types of unit resident tests can be accessed:
• Electronics Self-Test - (Level 1 test) To invoke the diagnostic, a good portion of
the controller hardware and software must be functioning properly. This is the
premise this test is based on: that full power-up testing is not necessary.
Therefore, this test does an extension of the power-up self tests. The code ROM
EDC is verified, two queues used by much of the controller software is checked by
dequeuing and enqueuing items.
The Send Diagnostic when there is a loader attached, a software reset is
performed on it. This test does not attempt to write or read data to or from media.
This test has an execution time of approximately 60 seconds which includes the
reset.
This test is specified by setting just the Self-Test bit (DevOfL, and UnitOfL both
zero).