User's Manual

DLT2000 SCSI Interface
DLT2000/DLT2700 Cartridge Tape Subsystem 8-115
8.4.21 SEND DIAGNOSTIC (1Dh)
Bit
76543210
0 Operation Code (1Dh)
Logical Unit Number PF Rsv’d Selftst Dev OfL UnitOfL
Reserved
Byte (MSB)
Parameter List Length
(LSB)
Unused Reserved Flag Link
1
2
3
4
5
Figure 8-73 SEND DIAGNOSTIC CDB
SEND DIAGNOSTIC tells the drive to perform diagnostic tests on itself.
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.
If there is a loader attached, a software reset is done on it. This test does not
attempt to write or read data to or from media. When complete, any errors are
posted in the extended Sense Data bytes. This test has an execution time of
approximately 5 seconds.
This test is specified by setting just the Self-Test bit (DevOfL, and UnitOfL both
zero).
• Write/Read Functionality Test - (Level 2 test). The default version of this test does
the following:
- Writes 100 32 KB records on track 0.
- Rewinds the tape.
- Reads the records.
- Positions to the beginning of track 1.