© National Instruments Corp.
B-1
GPIB-PCII/IIA for Graphics
Appendix B
Changing Board and Device
Characteristics
This appendix contains instructions for changing the default board and device
characteristics of the NI-488.2 handler for MS-DOS/Windows.
Note:
Most graphics application software is written to use the default
configuration of the NI-488.2 handler. Do not change the default
parameters of the NI-488.2 handler unless your graphics application
manual instructs you to do so.
Board and Device Characteristics
Two groups of features can be changed in the handler file or configuration file.
The first group consists of the characteristics of the devices attached to your GPIB-
PCII/IIA. The second group consists of the characteristics of each GPIB-PCII/IIA
installed in the computer. The following sections describe the characteristics of
each group.
Characteristics of the Graphics Devices
Each device used with the GPIB-PCII/IIA has the following characteristics:
•
A symbolic name of each device on the GPIB (such as
DEV5
or
SCANNER
).
•
A primary and, if used, a secondary address for each device.
•
A time limit imposed when executing certain functions. This time limit
ensures that transfers do not hang up the GPIB indefinitely.
•
A way to terminate I/O transmissions to and from the device. Some devices
require or append an end of string (EOS) character, such as the ASCII line
feed character, to data strings. Others use the GPIB END message, which is
sent or received via the EOI signal line. Still others use both. Some terminate
I/O only when a predetermined number of bytes are sent or received.
