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Appendix A
Tutorial
© National Instruments Corp.
A-5
GPIB-410 User Manual
4.
Control the GPIB by manipulating the monitor to simulate bus activity.
Initially, set up the data lines to the pattern 01011111 by pressing the
keys <w>, <r>, <t>, <y>, <u>, and <i>. This data pattern represents an
ASCII underscore (_). Alternatively, you can press <Ins> once to get
the prompt
<<<character>>>
above the data line switches and then
type an underscore. Notice that the ASCII underscore is also the GPIB
Untalk (UNT) command. (If you are unfamiliar with the IEEE-488
command set, refer to Appendix B for a complete listing of the
multiline interface messages and their ASCII equivalents.) At this
point, the monitor window appears as follows:
Press <k> twice for a data transfer handshake. This causes the DAV
line to toggle up and down one time.
Next, set ATN true by pressing <s>. The monitor window appears as
follows:
Toggle the DAV line twice more by pressing <k> four times.
Now, set ATN false by pressing <s> again. Toggle DAV by pressing
<k> an even number of times until you hear a beep and
CAP
is no
longer displayed in the title/status bar. This indicates that the capture
buffer is full and that the capture is complete. At this point, the DAV
switch should be down and the DAV LED should be off.