National Instruments PCI-6023E - Manual (Page 120)

Glossary
© National Instruments Corporation G-13 PCI-6023E/6024E/6025E User Manual
RTSI bus real-time system integration bus—the National Instruments timing bus that
connects DAQ boards directly, by means of connectors on top of the boards,
for precise synchronization of functions
S
s seconds
S samples
sample counter the clock that counts the output of the channel clock, in other words, the
number of samples taken. On boards with simultaneous sampling, this
counter counts the output of the scan clock and hence the number of scans.
scan one or more analog or digital input samples. Typically, the number of input
samples in a scan is equal to the number of channels in the input group. For
example, one pulse from the scan clock produces one scan which acquires
one new sample from every analog input channel in the group.
scan clock the clock controlling the time interval between scans.
scan rate the number of scans per second. For example, a scan rate of 10 Hz means
sampling each channel 10 times per second.
SCXI Signal Conditioning eXtensions for Instrumentation—the National
Instruments product line for conditioning low-level signals within an
external chassis near sensors so only high-level signals are sent to DAQ
boards in the noisy PC environment
SE single-ended—a term used to describe an analog input that is measured
with respect to a common ground
self-calibrating a property of a DAQ board that has an extremely stable onboard reference
and calibrates its own A/D and D/A circuits without manual adjustments by
the user
sensor a device that responds to a physical stimulus (heat, light, sound, pressure,
motion, flow, and so on), and produces a corresponding electrical signal
settling time the amount of time required for a voltage to reach its final value within
specified limits
PCI.book Page 13 Wednesday, September 16, 1998 9:09 AM