Glossary
© National Instruments Corporation G-7 653X User Manual
pretrigger acquiring data that occurs before a trigger
propagation delay the amount of time required for a signal to pass through a circuit
protocol the exact sequence of bits, characters and control codes used to transfer data
between computers and peripherals through a communications channel,
such as the GPIB
PXI PCI eXtensions for Instrumentation—a rugged, open system for modular
instrumentation based on CompactPCI, with special mechanical, electrical,
and software features
Rreal time a property of an event or system in which data is processed as it is acquired
instead of being accumulated and processed at a later time
REQ Request—Handshaking signal generated by the peripheral device,
indicating it is ready. In some transfer modes, the 653X device can
internally generate a REQ signal. The REQ signal with a bar above the
name indicates it is an inverted request signal.
RGND reserved ground
RT Series DAQ Device A collection of one, two, or four ports and an associated timing controller.
All handshaking I/O, pattern I/O and buffered operations must be
performed on groups.
RTSI bus Real-Time System Integration Bus—the National Instruments timing bus
that connects DAQ devices directly, by means of connectors on top of the
devices, for precise synchronization of functions
Ss seconds
S samples
S/s Samples per second—used to express the rate at which a DAQ device
samples an analog signal
sample an instantaneous measurement of a signal, normally using an
analog-to-digital convertor in a DAQ device