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NI-DAQmx Base 3.x C Function Reference Help
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Task Configuration/Control
DAQmxBaseClearTask
DAQmxBaseCreateTask
DAQmxBaseIsTaskDone
DAQmxBaseLoadTask
DAQmxBaseResetDevice
DAQmxBaseStartTask
DAQmxBaseStopTask
Channel Configuration/Creation
Create Analog Input Channels
DAQmxBaseCreateAIThrmcplChan
DAQmxBaseCreateAIVoltageChan
Create Analog Output Channel
DAQmxBaseCreateAOVoltageChan
Create Digital Input Channels
DAQmxBaseCreateDIChan
Create Digital Output Channels
DAQmxBaseCreateDOChan
Create Counter Input Channels
DAQmxBaseCreateCIPeriodChan
DAQmxBaseCreateCICountEdgesChan
DAQmxBaseCreateCIPulseWidthChan
Position
DAQmxBaseCreateCILinEncoderChan
DAQmxBaseCreateCIAngEncoderChan
Create Counter Output Channels
DAQmxBaseCreateCOPulseChanFreq
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DAQmxBaseCfgSampClkTiming
DAQmxBaseCfgImplicitTiming
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Start Trigger
DAQmxBaseDisableStartTrig
DAQmxBaseCfgDigEdgeStartTrig
DAQmxBaseCfgAnlgEdgeStartTrig
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DAQmxBaseCfgAnlgEdgeRefTrig
DAQmxBaseCfgDigEdgeRefTrig
DAQmxBaseDisableRefTrig
Read Functions
DAQmxBaseReadAnalogF64
DAQmxBaseReadBinaryI16
DAQmxBaseReadCounterF64
DAQmxBaseReadCounterScalarF64
DAQmxBaseReadCounterScalarU32
DAQmxBaseReadCounterU32
DAQmxBaseReadDigitalScalarU32
DAQmxBaseReadDigitalU32
DAQmxBaseReadDigitalU8
Write Functions
DAQmxBaseWriteAnalogF64
DAQmxBaseWriteDigitalU8
DAQmxBaseWriteDigitalU32
DAQmxBaseWriteDigitalScalarU32
Export HW Signals
DAQmxBaseExportSignal
Internal Buffer Configuration
DAQmxBaseCfgInputBuffer
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DAQmxBaseGetExtendedErrorInfo
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DAQmxBaseCreateCICountEdgesChan

int32 DAQmxBaseCreateCICountEdgesChan (TaskHandle taskHandle, const char counter[ ], const char nameToAssignToChannel[ ], int32 edge, uInt32 initialCount, int32 countDirection);

Purpose

Creates a channel to count the number of rising or falling edges of a digital signal and adds the channel to the task you specify with taskHandle. You can create only one counter input channel at a time with this function because a task can include only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to which to add the channels that this function creates.
counter const char [ ] The name of the counter to use to create virtual channels such as Dev1/ctr0.
nameToAssignToChannel const char [ ] Pass NULL for this parameter. NI-DAQmx Base currently ignores this parameter.
edge int32 Specifies on which edges of the input signal to increment or decrement the count.

Value Description
DAQmx_Val_Rising Rising edge(s).
DAQmx_Val_Falling Falling edge(s).
initialCount uInt32 The value from which to start counting.
countDirection int32 Specifies whether to increment or decrement the counter on each edge.

Value Description
DAQmx_Val_CountUp Increment the count register on each edge.
DAQmx_Val_CountDown Decrement the count register on each edge.
DAQmx_Val_ExtControlled The state of a digital line controls the count direction. Each counter has a default count direction terminal. The default for Counter 0 is PFI 10. The default for Counter 1 is PFI 11.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.
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