TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE
4-54 CG00000-011503 REV. A April 1997
Page Descriptor:
If the initiator sends page fields with values that are not supported by the target or are not Change-
able, the target returns a CHECK CONDITION status with the sense key field set to ILLEGAL
REQUEST in the sense data. In this case, no parameters are changed by this command.
More information on the MODE SELECT command can be found in paragraph 5-2 on page 5-1.
5-7 The Block Length field specifies the length in bytes of each logical block
described by the block descriptor. A block length of 0 indicates the length
is variable. Reference the READ BLOCK LIMITS command description
for the minimum and maximum block lengths supported.
Table 4-49. Page Descriptors
BITS
BYTES 7 6 5 4 3 2 1 0
0PS=0 Reserved Page Code
1Additional Page Length (see section 5-2 on page 5-1)
2 - N Page Defined or Vendor Unique Parameter Bytes
Table 4-50. Page Descriptor Field Description
BYTE BIT VALUE DESCRIPTION
0 0-5 Following the block descriptor (if supplied) are MODE SELECT pages.
The Page Code field identifies the format and parameters for that page.
This controller supports pages 01h (Error Recovery and Reporting), 02h
(Disconnect/Reconnect control), 0Ah (Control Mode Page), 10h (Device
Configuration Parameters) and 00h (Vendor Unique Parameters).
0 7 0h When using a MODE SELECT command, the PS (Parameters Savable) bit
is reserved and must be zero.
1 0-7 The Additional Page Length indicates the number of bytes in that page.
The additional page length field value does not include bytes 0 and 1 of
that page (the page code and additional page length fields, respectively). If
the initiator does not set this value to the value that is returned for the page
by the MODE SENSE command, the target will present CHECK CONDI-
TION status with the sense key set to ILLEGAL REQUEST and the addi-
tional sense code set to INVALID FIELD IN PARAMETER LIST.
Table 4-48. Block Descriptor Field Description (Continued)
BYTE BIT VALUE DESCRIPTION