Fujitsu M2488 manual Mode Sense MC command 1Ah, Mode Sense Field Description

M2488 PRODUCT GUIDE MEDIA CHANGER COMMANDS

6-2.3 MODE SENSE MC command 1Ah

The MODE SENSE medium-changer command provides a means for a target to report its medium changer device parameters to the initiator. The MODE SENSE command is a complementary com- mand to the MODE SELECT command. Please refer to the description of the MODE SELECT com- mand for recommendations on how to ensure that the MODE SELECT command performs the desired operations.

6-2.3.1 MODE SENSE CDB Description

MODE SENSE is a six-byte command. The bytes are shown below and described in the following paragraphs. 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		0		1		0
1
				LUN			0					DBD			Reserved
2
		PC							Page Code (see section					6-3 on page 6-32)
3										Reserved
4
								Allocation Length
5
						Reserved										Flag		Link

Note: Changeable fields in the CDB are shaded.

For both an ACL or an FACL, the target will perform the MODE SELECT command even if the Medium Changer LUN is NOT READY.

			Table 6-9. MODE SENSE Field Description
BYTE	BIT	VALUE		DESCRIPTION
0	0-7	1Ah		Operation code.
1	3	1		The Disable Block Descriptor (DBD) bit value of 1 specifies that no block descrip-
				tor is returned in the MODE SENSE data.
		0		Since the Medium Changer does not provide a block descriptor, the Block Descrip-
				tor Length field in the MODE SENSE data read will always be set to zero indepen-
				dent of the setting of the DBD bit in the MODE SENSE command.
2	0-5			The Page Code allows the initiator to select any specific page or all of the pages sup-
				ported by a target. Pages are used to set and return device parameters. If the initiator
				uses a Page Code value not implemented by the target, the target will return CHECK
				CONDITION status with sense key set to ILLEGAL REQUEST, and additional
				sense code to INVALID FIELD IN CDB.

March 1997 CG00000-011503 REV. A 6-11