National Instruments GPIB-SCSI-A, Руководство пользователя

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Chapter 7 G Mode Functions
© National Instruments Corp. 7-89 GPIB-SCSI-A User Manual
space - Space
Type: SCSI function
Syntax:
space code, count
Purpose: Use
space
to command the GPIB-SCSI-A to process the
Group 0 SCSI SPACE command.
Remarks: The GPIB-SCSI-A uses the following Command Descriptor
Block to command the Target to process
space
. Notice how
the parameters to the
space
command are used in the
creation of the Command Descriptor Block.
Bit 7 6 5 4 3 2 1 0
Byte
0 11
1 LUN Code
2 Count (Most Significant Byte)
3 Count (Middle Significant Byte)
4 Count (Least Significant Byte)
5 VCB 00
The Count and Code in the Command Descriptor Block are
given as parameters to the
space
command. The LUN
corresponds to the last value assigned with the
lun
command.
The VCB corresponds to the last value assigned with the
vcb
command.
During the execution of this command, if the GPIB-SCSI-A
encounters a phase which it does not expect, an EPHS error
indication results. For a list of the expected phases, refer to
the section titled Handling of SCSI Phases in G Mode in
Chapter 6, Programming in G Mode.
Refer to your SCSI device documentation for the expected
values in each byte of the Command Descriptor Block and the
SCSI phases that the device creates.