
Glossary
NI-488.2M UM for Windows NT
Glossary-6
© National Instruments Corp.
N
NDAC
One of the three GPIB handshake lines. See handshake .
(Not Data Accepted)
NRFD
One of the three GPIB handshake lines. See handshake .
(Not Ready For Data)
P
parallel poll
The process of polling all configured devices at once and
reading a composite poll response. See serial poll .
PIO
See programmed I/O.
PPC
Parallel Poll Configure is the GPIB command
(Parallel Poll Configure)
used to configure an addressed Listener to participate in polls.
PPD
Parallel Poll Disable is the GPIB command used
(Parallel Poll Disable)
to disable a configured device from participating in polls.
There are 16 PPD commands.
PPE
Parallel Poll Enable is the GPIB command used
(Parallel Poll Enable)
to enable a configured device to participate in polls and to
assign a DIO response line. There are 16 PPE commands.
PPU
Parallel Poll Unconfigure is the GPIB command
(Parallel Poll
used to disable any device from participating in
Unconfigure)
polls.
programmed I/O
Low-speed data transfer between the GPIB board and memory
in which the CPU moves each data byte according to program
instructions. See DMA .
R
RAM
Random-access memory.
resynchronize
The NI-488.2M software and the user application must
resynchronize after asynchronous I/O operations have
completed.
RQS
Request Service.