National Instruments GPIB-232CV, User Manual

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Application Examples Appendix C
GPIB-232CV User Manual C-2 © National Instruments Corp.
1. Use
ibconf
to configure the system so that a device named either
printer or plotter is connected to the GPIB interface board. Be sure to
enable DMA transfers and to use high-speed timing.
2. Configure the GPIB-232CV to operate in D mode with the small (256
bytes) serial port buffer and SRQ disabled. The serial buffer is set to
the smallest size to allow the GPIB port, which is the data source, to
use the majority of RAM. Set the GPIB address to the same address
assigned to the device plotter or printer in
ibconf
. Configure the
serial port parameters to match those of the printer or plotter.
3. Connect the GPIB cable from the PC to the GPIB-232CV, and connect
the serial cable from the GPIB-232CV to the printer or plotter. The
system should resemble the diagram in Figure C-1.
Serial
Cable
GPIB
Cable
GPIB-232CV
GPIB-422CV
IEEE 488 RS-422 CONVERTER
POWER READY TALK LISTEN BUSY FULL
IBM PC AT
(GPIB Controller)
Printer
(Serial Device)
Figure C-1. Example of Print Spooler Setup
4. Provide a means to transfer data to the printer or plotter easily via the
GPIB port on your PC. You can simply redirect the serial output to the
GPIB device as explained in the NI-488.2 Software Reference Manual
for MS-DOS which is provided with the National Instruments
AT-GPIB board, but the overhead associated with the DOS calls makes
this method inherently slow. The fastest way to transfer data to the
GPIB port is to write a small program that executes a GPIB file write.
The following program is an example of how to do a GPIB file write in
the C programming language. You can use other languages in the same
way.