Filter
Top Products
Easy I/O for DAQ Library Chapter 10
LabWindows/CVI Standard Libraries 10-16 © National Instruments Corporation
AIReadAcquisition
short
error
=
AIReadAcquisition
(unsigned long
taskID
, long
scanstoRead,
unsigned short
readMode
,
unsigned long *
scanBacklog,
short
fillMode
, double
waveforms
[]);
Purpose
This function reads the specified number of scans from the internal circular buffer established by
AIStartAcquisition.
If the specified number of scans is not available in the buffer, the function waits until the scans
are available. You can call AICheckAcquisition before calling AIReadAcquisition to
determine how many scans are available.
Parameters
Input
taskID
unsigned long
integer
The task ID that was returned from
AIStartAcquisition.
scanstoRead
long integer The number of scans that are read from the internal
circular buffer.
readMode
unsigned
short integer
Specifies whether scans are read from the circular
buffer in CONSECUTIVE_MODE or
LATEST_MODE.
fillMode
short integer Specifies one of the following modes for the
waveforms array: GROUP_BY_CHANNEL or
GROUP_BY_SCAN.
Output
scanBacklog
unsigned long
integer
Returns the backlog of scans that have been acquired
into the circular buffer but have not been read using
AIReadAcquisition.
waveforms
double array Array containing the voltages acquired on the
channels specified in the
channelString
.
Return Value
error
short integer Refer to error codes in Table 10-5.
Parameter Discussion
readMode
specifies whether scans are read from the circular buffer in CONSECUTIVE_MODE or
LATEST_MODE. In CONSECUTIVE_MODE scans are read from the internal circular buffer
starting from the last scan that was read. Using this mode, you are guaranteed that you will not
lose data unless an error occurs. In LATEST_MODE the most recently acquired n scans are read