Fujitsu M2488 manual Send Diagnostic command 1Dh, Send Diagnostic CDB Description

M2488 PRODUCT GUIDE TAPE UNIT SCSI COMMANDS

4-3.27 SEND DIAGNOSTIC command 1Dh

The SEND DIAGNOSTIC 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 operation. Disconnection occurs, if allowed, during the execution of the function. When the Selftest bit is zero, this command is usually followed by a RECEIVE DIAGNOSTIC RESULTS command.

4-3.27.1 SEND DIAGNOSTIC CDB Description

SEND DIAGNOSTIC is a six-byte command. The bytes are shown below and described in Table 4-107. Common fields are described in paragraph 4-3.1 on page 4-4.

									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.

The following Field Description table specifies the use of each field of the SEND DIAGNOSTIC CDB. Refer to Table 4-108 in conjunction with the following table for a more concise overview of how each field is used.

Table 4-107. SEND DIAGNOSTIC 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	A Selftest bit of 1 directs the target to complete its default selftest.
		0	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.

April 1997 CG00000-011503 REV. A 4-117