Field Definitions - Spectra Logic Spectra 10000 User Manual

10kdev_.book Page 66 Friday, March 12, 1999 9:44 AM

Field Definitions

Logical Unit Number (Byte 01, bits 7-5)
The library does not support Logical Unit Numbers so this field must be 00h.
DBD (Byte 01, bit 3)
The library does not use block descriptors. The value for the Disable Block Descriptors
field should be 1.
PC (Byte 02, bits 7-6)
The Page Control field defines the type of parameters that are to be returned for the
Mode Sense command. The valid values for this field are as follows:
0 = Current Values (00h) Indicates that the library returns the current mode parameters.
The current values returned are:
•
The parameters set in the last successful Mode Select command.
•
The saved values if a Mode Select command has not been executed since the last
power-on, SCSI bus reset condition, or Bus Device Reset message.
•
The default values if saved values are not available.
1 = Changeable Values (01h) Indicates that the library returns the changeable parameter
masks. The requested pages are returned and indicate which parameters are changeable
by the initiator. All bits of changeable parameters are set to 1. All bits of parameters that
are not changeable by the initiator are set to 0.
Prior to issuing any Mode Select commands, issue a Mode Sense command
Note:
with the PC field set to 01h and the Page Code field set to 3Fh to determine which
pages are supported, which parameters within the pages are changeable, and the
supported length of each page.
2 = Default Values (02h) Indicates that the library returns the default values. The
requested pages are returned with each supported parameter set to its default value.
Parameters not supported by the library are set to 0.
3 = Saved Values (03h) Indicates that the library returns the saved values. The requested
pages are returned from the library's FPROM memory with each supported parameter set
to its saved value. Parameters not supported by the library are set to 0.
For a Page Control value of 03h, and if no page has been saved, default values
Note:
are returned.
Chapter 7