Measurement Computing Data Acquisition Systems rev.10.4 User Manual

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Returns

DerrNoError

error

Function Usage

The term waveform/pattern output is used extensively throughout the entries for the
functions of the form daqDac…. This refers to an analog waveform output modes and/or
digital pattern output modes. These terms describe output to DAC and/or digital output
channels that are synchronously updated by a clock source defined by the application.

The daqDacWaveSetTrig function is used to setup the trigger event to initiate a waveform/pattern output
for all channels which have been configured for waveform/pattern output mode. For more information on
configuring channels for waveform/pattern output, see the daqDacSetOutputMode function.

Setting the Waveform/pattern Output Trigger Event

The triggerSource parameter specifies the source of the event that will trigger the waveform/pattern
output operation. Currently, there are only two valid trigger events that can be set with the triggerSource
parameter. The first, set with the value DdtsImmediate, indicates that the waveform/pattern output
operation should trigger immediately upon being armed. The second, set with the value DdtsImmediate,
indicates that the waveform/pattern output operation should be triggered upon the application issuing a
command to do so. The deviceType and chan parameters must correspond with a channel that has been
configured for waveform/pattern output using the daqDacSetOutputMode function. The trigger event
values are defined as follows:

DdtsImmediate

– Trigger the waveform/pattern output operation immediately upon execution of the

daqDacWaveArm

function. This trigger source is used to trigger the waveform/pattern output immediately

upon successfully arming the operation. Since, however, many of the configuration error conditions and
conflicts are detected during the arm operation, it is important to handle error conditions properly when using
this trigger source.

DdtsSoftware

– Trigger the waveform/pattern output operation upon execution of the

daqDacWaveSoftTrig

function. This trigger source requires that the daqDacWaveArm function be

issued before the daqDacWaveSoftTrig function. Once armed, the application may trigger the
waveform/pattern output operation at any time by issuing daqDacWaveSoftTrig function.

DdtsAdcClock

– Trigger on the ADC clock, useful when trying to synchronize the waveform/pattern output

with the ADC clock. This trigger source is valid only for Daq 2000 Series devices.

The rising flag is currently ignored and is reserved for future use.

Prototypes

C/C++

daqDacWaveSetTrig(DaqHandleT handle, DaqDacDeviceType deviceType, DWORD
chan, DaqDacTriggerSource triggerSource, BOOL rising);

Visual BASIC

VBdaqDacWaveSetTrig&(ByVal handle&, ByVal deviceType&, ByVal chan&, ByVal
triggerSource&, ByVal rising&)

Program References

DAQDACEX02.CPP, DAQDACEX03.CPP

4.4-40 Daq API Command Reference

908494

Programmer’s

Manual