start
Start DataAcquisition
background operation
Syntax
Description
start(
starts the
d
)DataAcquisition
interface background operation. When the input
acquisition and output generation begin depends on channel configuration and preloaded
output data:
If the
DataAcquisition
interface has only input channels, the acquisition begins immediately, collecting scan data, which you can access later with theread
function. The default scan duration is1
second.If the
DataAcquisition
interface has only output channels, generation begins immediately if data is already queued with thepreload
function. If no data is queued, output begins when data is made available withwrite
function.If the
DataAcquisition
interface has both input and output channels, the input acquisition begins and ends at the same time as the output generation, resulting in the same number of scans.
start(
starts the background
operation running continuously. If there is data already available from the
d
,"Continuous")preload
function, output generation begins immediately along with
acquisition on any input channels. Otherwise, acquisition begins when you execute
write
. The operation continues until you call
stop
. As output scan data is generated or input scan data is
acquired, you might need to call write
or read
while the DataAcquisition
background operation is still running.
start(
starts the background
operation, generating periodic output in a repeating loop of the output scan data. If there
is data already available from the d
,"RepeatOutput")preload
function, output generation
begins immediately along with acquisition on any input channels. Otherwise, generation and
acquisition begin when you execute write
. The operation continues until
you call stop
. If input scan data is being acquired, you might need to
call read
while the DataAcquisition
background
operation is still running.
start(
or d
,"Duration",span
)start(
starts the background input acquisition to run for a finite span of time, specified as
either a duration or a number of scans. If the d
,"NumScans",span
)DataAcquisition
interface
has any output channels, the start occurs but the duration specification is ignored.
Examples
Input Arguments
Version History
Introduced in R2020a
See Also
Functions
Topics
- Generate Signals in the Background
- Generate Signals in the Background Continuously
- Generate Continuous and Background Signals Using NI Devices
- Acquire Continuous and Background Data Using NI Devices
- Log Analog Input Data to a File Using NI Devices
- Communicate with I2C Devices and Analyze Bus Signals Using Digital IO
- Generate Pulse Width Modulated Signals Using NI Devices
- Acquire Continuous Audio Data
- Create an Echometer Using Audio Measurements
- Acquire Data from Two Devices at Different Rates