Glossary
G-4
ni.com
DAQD*/A
The data acquisition board 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.
device
A plug-in data acquisition board, module, card, or pad that can contain
multiple channels and conversion devices.
differential amplifier
An amplifier with two input terminals, neither of which are connected to a
ground reference, whose voltage difference is amplified.
DIN
Deutsche Industrie Norme (German Industrial Standard).
DIO
Digital input/output.
drivers/driver
software
Software that controls a specific hardware device, such as an E/M Series
DAQ device.
E
EEPROM
Electrically Erasable Programmable Read-Only Memory—ROM that can
be erased with an electrical signal and reprogrammed. Some SCXI modules
contain an EEPROM to store measurement-correction coefficients.
EMC
Electromagnetic compliance.
EMI
Electromagnetic interference.
excitation
Supplying a voltage or current source to energize an active sensor or circuit.
F
FIFO
First-in first-out memory buffer.
filtering
A type of signal conditioning that allows you to remove unwanted
frequency components from the signal you are trying to measure.
flexible scanning
The hardware capability to sequence through channels in a scan list in any
order.