National Instruments GPIB-SCSI-A, Руководство пользователя

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Chapter 7 G Mode Functions
© National Instruments Corp. 7-21 GPIB-SCSI-A User Manual
dtout - Transfer Data Out Information to Selected
SCSI Target
Type: SCSI Function
Syntax:
dtout
<CR>
Purpose: Use the
dtout
command in your low-level command
sequence to perform the Data Out phase for the SCSI bus.
Remarks: You must use the
dtout
command in your low-level
command sequence to perform the Data Out phase for the
SCSI bus.
Because this command is used to transfer GPIB data (which is
not grouped in blocks) to the SCSI (which is usually grouped
in blocks), the GPIB-SCSI-A uses the GPIB END message to
prevent locking up the system.
You must assert the GPIB EOI* signal on the last byte of data
transferred to the Data Channel. At this time, the
GPIB-SCSI-A transfers the
pad
byte specified by
pad
until
the selected SCSI device changes from the Data Out phase.
If the Target enters the Status phase before entering the Data
Out phase,
dtout
aborts the operation with an error
indication of EPHS.
If the selected Target changes from the Data Out phase before
the GPIB-SCSI-A has received the END message from the
GPIB, the GPIB-SCSI-A terminates this command with an
EPHS error.
If there is anything following
dtout
, the command aborts the
operation with an EARG indication.
See Also: pad, wrext, write,
and
Appendix D, Operation of the SCSI.