Space - Space - National Instruments GPIB-SCSI-A User Manual

Chapter 7

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.
Byte
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.
© National Instruments Corp.
Bit 7 6
0
1 LUN
2
3 Count (Middle Significant Byte)
4
5 VCB
5 4
11
Count (Most Significant Byte)
Count (Least Significant Byte)
7-89 GPIB-SCSI-A User Manual
G Mode Functions
3 2 1
Code
00
0