National Instruments NI PCI-5911 User Manual

Page 45

Glossary

G-7

pretriggering

the technique used on a device to keep a buffer filled with data, so that when
the trigger conditions are met, the sample includes the data leading up
to the trigger condition

PXI

PCI eXtensions for Instrumentation. PXI is an open specification that
builds off the CompactPCI specification by adding
instrumentation-specific features.

resistor

RAM

random-access memory

real-time sampling

sampling that occurs immediately

random interleaved
sampling (RIS)

method of increasing the sample rate by repetitively sampling a repeated
waveform

resolution

the smallest signal increment that can be detected by a measurement
system. Resolution can be expressed in bits or in digits. The number of bits
in a system is roughly equal to 3.3 times the number of digits.

rms

root mean square—a measure of signal amplitude; the square root of the
average value of the square of the instantaneous signal amplitude

ROM

read-only memory

RTSI bus

real-time system integration bus—the National Instruments timing bus that
connects devices directly, by means of connectors on top of the boards, for
precise synchronization of functions

seconds

samples

S/s

samples per second—used to express the rate at which an instrument
samples an analog signal. 100 MS/s would equal 100 million samples each
second.