Measurement Computing Data Acquisition Systems rev.10.4 - Manual (Page 195)

Before Invoking daqDacWaveArm
This function requires that all waveform channels are properly set to the correct modes and that the
waveform/pattern output trigger events, the output modes, and the update clock are all set before this function
is invoked. Specifically, the following steps need to be performed before calling this function:
•
Configure all the output channels to be included in the waveform/pattern output as static or dynamic
output mode (DdomStaticWave or DdomDynamicWave) via the daqDacSetOutputMode
function.
•
If streaming output from a file, then set the disk file using the daqDacWaveSetDiskFile for each
channel that as been configured for waveform/pattern output (the disk file should name should be the
same for all output channels).
•
Set the waveform/pattern output clock source for each output channel via the
daqDacWaveSetClockSource
function.
•
If the selected clock source uses the internal waveform/pattern output pacer clock, then set the output
update frequency using the daqDacWaveSetFreq function.
Set the trig daqDacWaveSetTrig
•
ger event which will initiate the waveform/pattern output via the
•
eform/pattern output termination conditions using the
•
ated and the transfer
(daqDacWaveSetBuffer and the
daqDacTransferStart functions.
Aft
vice
as DdtsImmediate). The trigger event is configured using the daqDacWaveSetTrig
o
ogress of the
ny waveform/pattern output may be terminated by issuing
nction is invoked, any potential configuration
problems or parameter value conflicts will be detected here.
function.
Configure the update mode and wav
daqDacWaveSetMode
function.
Though it is not required, it is also recommended that the transfer buffer is alloc
is enabled prior to invoking this function
er Invoking daqDacWaveArm
Once the preliminary steps have been taken to setup up daqDacWaveArm, it can be used to arm the de
for waveform/pattern output. However, the device will not begin the actual output of data to the ports
configured for waveform/pattern output until the trigger event has occurred (unless the trigger event is
configured
function.
Once triggered, the device will begin outputting data from its internal output FIFO. Therefore, it is important
to have already transferred at least the first block of data from the application allocated output transfer buffer t
the device’s internal output buffer before the trigger event occurs. For more information on transferring data
from the application to the internal output FIFO, see daqDacWaveSetBuffer and
daqDacTransferStart
. While the waveform/pattern output operation is occurring, the pr
waveform/pattern output may be monitored using the daqDacTransferStart function.
The waveform/pattern output will terminate based upon the update mode set by the daqDacWaveSetMode
function. Regardless of the update mode, however, a
the daqDacWaveDisarm function for the device.
When this function is invoked, the driver determines if there are any problems with any of the
waveform/pattern output configuration parameters issued by application. Since the bulk of the actual
waveform/pattern output configuration is performed when this fu
Programmer’s Manual 908494 Daq API Command Reference 4.4-13