Keithley KPCI-PIO32IOA User Manual page 66

KPCI-PIO32IOA and KPCI-PDISO8A User's Manual Glossary C-3
FIFO
First-in/first-out memory buffer. The first data into the buffer is the first data out of the buffer.
GPIB
Abbreviation for General Purpose Interface Bus. It is a standard for parallel interfaces.
IEEE-488
See GPIB.
Input/Output (I/O)
The process of transferring data to and from a computer-controlled system using its communica-
tion channels, operator interface devices, data acquisition devices, or control interfaces.
1
Input/output port
A channel through which data is transferred between an input or output device and the
processor.
ISA Bus
Industry Standard Architecture. The 16-bit wide bus architecture used in most MS-DOS and
Windows computers. Sometimes called the AT bus.
1
Map
Any representation of the structure of an object. For example, a memory map describes the lay-
out of objects in an area of memory, and a symbol map lists the association between symbol
names and memory addresses in a program.
OCX
Abbreviation for OLE Custom Control.
Pass-through operation
See target mode.
PCI
Abbreviation for Peripheral Component Interconnect. It is a standard for a local bus.
Port
See input/output port.
Port I/O call
A software program statement that assigns bit values to an I/O port or retrieves bit values from
an I/O port. Examples include a C/C++ statement containing an inp or outp function or a
Basic statement containing a peek or poke function.
1
Register
A set of bits of high speed memory within a microprocessor or other electronic device, used to
hold data for a particular purpose.
Shielding
A metal enclosure for the circuit being measured or a metal sleeve surrounding wire conductors
(coax or triax cable) to lessen interference, interaction, or current leakage. The shield is usually
grounded.
Target mode
A PCI bus mode in which data from a data acquisition board is transferred indirectly to the com-
puter memory in the foreground, via the host computer CPU, instead of directly, via Bus master-
ing. Sometimes referred to as pass-through operation. See also bus mastering and foreground
task.
1
Trap (verb)
To intercept an action or event before it occurs, usually in order to do something else.