TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE
4-124 CG00000-011503 REV. A April 1997
4-3.28 SEND DIAGNOSTIC (FACTORY MODE) command 1Dh
The SEND DIAGNOSTIC (FACTORY MODE) command requests the target to perform diagnostic
tests on itself, or on the attached peripheral devices. After the receipt of a valid SEND DIAGNOSTIC
command, the unit performs synchronization prior to execution of the SEND DIAGNOSTIC opera-
tion. Disconnection occurs, if allowed, during the execution of the function. When the self-test bit is
zero, this command is usually followed by a RECEIVE DIAGNOSTIC RESULTS command.
** NOTE **
The SEND DIAGNOSTIC command as described in this section
requires that the tape drive be set in FACTORY MODE.
4-3.28.1 SEND DIAGNOSTIC CDB Description
SEND DIAGNOSTIC is a six-byte command. The bytes are shown below and described in
Table 4-114. Common fields are described in paragraph 4-3.1 on page 4-4.
The following Field Description table specifies the use of each field of the SEND DIAGNOSTIC
CDB. Refer to Table 4-115 in conjunction with the following table for a more concise overview of
how each field is used.
BITS
BYTES 7 6 5 4 3 2 1 0
0
0 0 0 1 1 1 0 1
1
LUN PF Reserved Selftest DevOfL UnitOfL
2
Reserved
3
MSB
Parameter List Length
4
LSB
5
Reserved Flag Link
Note: Changeable fields in the CDB are shaded.
Table 4-114. SEND DIAGNOSTIC (FACTORY MODE) Field Description
BYTE BIT VALUE DESCRIPTION
0 0-7 1Dh Operation code.
1 0 1 A UnitOfL (Unit Offline) bit of 1 enables write operations on user medium or opera-
tions that affect user visible medium positioning.
1 1 1 A DevOfL (Device Offline) bit of 1 enables diagnostic operations that may adversely
affect operations to other logical units on the same target.
1 2 1
0
A Selftest bit of 1 directs the target to complete its default selftest.
A Selftest bit of 0 directs the target to perform tests defined by the bytes in the
parameter list. Successful completion of the function and preparation of a response is
indicated by presentation of GOOD status. The response is then recovered by execu-
tion of the RECEIVE DIAGNOSTIC RESULTS command.
