Programming instructions

Glossary
© National Instruments Corporation G-13 LabVIEW Data Acquisition Basics Manual
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 n 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. On boards with
interval scanning support (for example, the AT-MIO-16F-5), this clock
gates the channel clock on and off. On boards with simultaneous sampling
(for example, the EISA-A2000), this clock clocks the track-and-hold
circuitry.
scan rate The number of times (or scans) per second that LabVIEW acquires data
from channels. For example, at a scan rate of 10Hz, LabVIEW samples
each channel in a group 10 times per second.
scan width The number of channels in the channel list or number of ports in the port
list you use to configure an analog or digital input group.
SCXI Signal Conditioning eXtensions for Instrumentation. The National
Instruments product line for conditional low-level signals within an
external chassis near sensors, so only high-level signals in a noisy
environment are sent to data acquisition boards.
scxi_ai.llb
A LabVIEW DAQ library containing VIs specific to analog input
SCXI modules.
scxi_ao.llb
A LabVIEW DAQ library containing VIs specific to analog output
SCXI modules.
scxi_dig.llb
A LabVIEW DAQ library containing VIs specific to digital SCXI modules.
sec Seconds.
settling time The amount of time required for a voltage to reach its final value within
specified limits.
signal conditioning The manipulation of signals to prepare them for digitizing.
signal divider Performing frequency division on an external signal.
simple-buffered I/O Input/output operation that uses a single memory buffer big enough for all
of your data. LabVIEW transfers data into or out of this buffer at the
specified rate, beginning at the start of the buffer and stopping at the end of
the buffer. You use simple buffered I/O when you acquire small amounts
of data relative to memory constraints.