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Command Specifications
The MODE SELECT parameters include parameters which can be changed by the
INIT as desired, parameters which the INIT cannot change, which whose values
are determined by the IDD unilaterally and parameters which can be changed by
the INIT within certain appropriate limits. The IDD also contains parameter fields
which are applicable for rounding processing ("rounding up" or "rounding down")
of parameter values specified by the INIT to values which the IDD can use in
actual operation.
When changing of parameters other than "variable parameters" is requested by the
INIT in the MODE SELECT parameters which it transfers in this command, or
when changes which are outside the permissible range are requested, even though
they are "variable parameters," this command is terminated with a CHECK
CONDITION status (ILLEGAL REQUEST [=5] / Invalid field in parameter list
[=26-00]) and all the parameters specified by the INIT are disabled. Furthermore,
parameter fields exist which ignore the values specified by the INIT, even if the
parameters are "variable parameters." Details are explained in the description of
each page descriptor in this item.
If the IDD performs rounding processing ("rounding up" or "rounding down") of
parameter values specified by the INIT, in some cases a "CHECK CONDITION"
status (RECOVERED ERROR [=1] / Rounded parameter [37-00]) is reported, and
in some cases it is not reported.
Whether or not the CHECK CONDITION status is reported depends on whether
"rounding up" or "rounding down" is specified.
If the INIT would like to confirm that the IDD is implementing rounding
processing, it issues a MODE SENSE or MODE SENSE EXTENDED command
after issuing this command and reads the values for the "Current" parameters, then
compares them with the parameter values sent in the MODE SELECT command.
Parameter fields which are the object of rounding processing are explained in the
descriptions of each page descriptor in this item.
Table 4.13 lists the data configuration of the parameter list transferred by the INIT
in this command. The parameter list is configured from header 4 bytes in length
followed by a block descriptor with a length of 8 bytes. This is followed by one
or more page descriptors, or, when there is no block descriptor the 4-byte header
is followed by one or more page descriptors. The INIT may transfer a header
only, or the header and block descriptor only without the page descriptor added.
4-20
C141-C009
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