Glossary
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National Instruments Corporation
G-3
SCXI-1502 User Manual
CH
Analog input channel signal.
CH GND
Chassis ground signal.
channel
Pin or wire lead to which you apply or from which you read the analog or
digital signal. Analog signals can be single-ended or differential. For digital
signals, you group channels to form ports. Ports usually consist of either
four or eight digital channels.
chassis
The enclosure that houses, powers, and controls SCXI modules.
CJ SENSOR
Cold-junction temperature sensor.
CLK
Clock input signal.
clock
Hardware component that controls timing for reading from or writing to
groups.
CMRR
Common-mode rejection ratio—a measure of the ability of a differential
amplifier to reject interference from a common-mode signal, usually
expressed in decibels (dB).
common-mode voltage
Voltage that appears on both inputs of a differential amplifier.
cutoff frequency
The frequency that defines the upper end of the passband of a lowpass filter.
D
D/A
Digital-to-analog.
D GND
Digital ground signal.
D OUT
Digital output signal.
DAQ device
A data acquisition device.
DAQD*/A
The data acquisition device data/address line signal used to indicate
whether the SER DAT IN pulse train transmitted to the SCXI chassis
contains data or address information.
dB
Decibel—the unit for expressing a logarithmic measure of the ratio of
two signal levels: dB = 20log
10
V1/V2, for signals in volts.
DC
Direct current.