Chapter 7
G Mode Functions
© National Instruments Corp.
7-107
GPIB-SCSI-A User Manual
wfmks - Write Filemarks
Type:
SCSI function
Syntax:
wfmks filemarks
<CR>
Purpose:
Use
wfmks
to command the GPIB-SCSI-A to process the
Group 0 SCSI WRITE FILEMARKS command.
Remarks:
The GPIB-SCSI-A uses the following Command Descriptor
Block to command the Target to process
wfmks
. Notice how
the parameter to the
wfmks
command is used in the creation
of the Command Descriptor Block.
Bit
7
6
5
4
3
2
1
0
Byte
0
10
1
LUN
00
2
Number of Filemarks (Most Significant Byte)
3
Number of Filemarks (Middle Significant Byte)
4
Number of Filemarks (Least Significant Byte)
5
VCB
00
The Number of Filemarks in the above Command Descriptor
Block is given as a parameter to the
wfmks
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 expected values
in each byte of the Command Descriptor Block and the SCSI
