Quantum DLT 8000 Product Manual page 355

SEND DIAGNOSTIC Command (1Dh) (continued)
Two levels of unit-resident diagnostic tests can be accessed:
Electronics Self-Test (Level 1 Test)
To invoke this level of diagnostic test, a major portion of the controller hardware
and software must be functioning properly. The test is based on the premise that
full power-up testing is not necessary, therefore, it is an extension of the power-up
self tests that are run. The code ROM EDC is verified, two queues used by much of
the controller software are checked by dequeuing and enqueuing items.
If a loader (Medium Changer) is configured, the test attempts a software reset on
the loader. This test does not attempt a WRITE or READ to or from the tape
medium. When complete, any errors that occur are reported in the extended Sense
Data bytes. This Level 1 test has an execution time of approximately five (5)
seconds.
Specify the Electronics Self-Test by setting the Selftst bit to 1, and both the
DevOfl and UnitOfl bits to 0.
Read / Write Functionality Test (Level 2 Test)
The default version of this test does the following:
1. Writes 500 32 KB records on track 0 (forward motion)
2. Rewinds the tape.
3. Reads the records.
4. Positions to the beginning of track 1 (backward motion)
5. Writes 500 32 KB records on track 1.
6. Repositions to the beginning of track 1.
7. Reads the records.
8. Rewinds the tape.
The execution time for this Level 2 test is approximately 6 minutes, if calibration
is not required. Specify the Read/Write test by setting both the Selftst bit and the
UnitOfl bit to 1 and ensuring that the DevOfl bit to 0.
A Level 3 (or test type III) is available with user defined parameters. In addition, SEND
DIAGNOSTIC can be used to invoke the BHC test (Figure 5-98 and Table 5-97). Note
that the BHC feature is provided for use only by a trained service provider.
Quantum DLT 8000 Tape System
SCSI Commands
5-211