Glossary
© National Instruments Corporation
G-7
NI-VXI User Manual
GPIO
General-Purpose Input Output, a module within the National
Instruments TIC chip which is used for two purposes. First, GPIOs
are used for connecting external signals to the TIC chip for
routing/conditioning to the VXIbus trigger lines. Second, GPIOs
are used as part of a crosspoint switch matrix.
H
handshaking
A type of protocol that makes it possible for two devices to
synchronize operations.
hardware context
The hardware setting for address space, access privilege, and byte
ordering.
hex
Hexadecimal; the numbering system with base 16, using the digits 0 to
9 and letters A to F.
high-level
Programming with instructions in a notation more familiar to the user
than machine code. Each high-level statement corresponds to several
low-level machine code instructions and is machine-independent,
meaning that it is portable across many platforms.
Hz
Hertz; a measure of cycles per second.
I
I/O
Input/output; the techniques, media, or devices used to achieve
communication between entities.
IACK
Interrupt Acknowledge
IEEE
Institute of Electrical and Electronics Engineers
IEEE 1014
The VME specification. Its full title is ANSI/IEEE 1014-1987, IEEE
Standard for a Versatile Backplane Bus: VMEbus.
IEEE 1155
The VXI specification. Its full title is ANSI/IEEE 1155-1992, VMEbus
Extensions for Instrumentation: VXIbus.
IEEE 488
Standard 488-1978, which defines the GPIB. Its full title is IEEE
Standard Digital Interface for Programmable Instrumentation. Also
referred to as IEEE 488.1 since the adoption of IEEE 488.2.
