National Instruments GPIB-SCSI-A, Руководство пользователя

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G Mode Functions Chapter 7
GPIB-SCSI-A User Manual 7-58 © National Instruments Corp.
rdbuf - Read Buffer
Type: SCSI function
Syntax:
rdbuf buffer id, buffer offset, allocation
length
<CR>
Purpose: Use
rdbuf
to command the GPIB-SCSI-A to process the
Group 1 SCSI READ BUFFER command.
Remarks: The GPIB-SCSI-A uses the following Command Descriptor
Block to command the Target to process
rdbuf
. Notice how
the parameters to the
rdbuf
command are used in the
creation of the Command Descriptor Block.
Bit 7 6 5 4 3 2 1 0
Byte
0 3C
1 LUN 02
2 Buffer Id
3 Buffer Offset (Most Significant Byte)
4 Buffer Offset (Middle Significant Byte)
5 Buffer Offset (Least Significant Byte)
6 Allocation Length (Most Significant Byte)
7 Allocation Length (Middle Significant Byte)
8 Allocation Length (Least Significant Byte)
9 VCB 00
The Buffer Id, Buffer Offset, and Allocation Length in the
Command Descriptor block are given as parameters to the
rdbuf
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.