DAQmxCreateAIFreqVoltageChan
int32 DAQmxCreateAIFreqVoltageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, float64 thresholdLevel, float64 hysteresis, const char customScaleName[]);
Purpose
Creates channel(s) that use a frequency-to-voltage converter to measure frequency and adds the channel(s) to the task you specify with taskHandle.
Parameters
| Input | |||||||||||
| Name | Type | Description | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| taskHandle | TaskHandle | The task to which to add the channels that this function creates. | |||||||||
| physicalChannel |
|
The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels. | |||||||||
| nameToAssignToChannel |
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The name(s) to assign to the created virtual channel(s). If you do not specify a name, NI-DAQmx uses the physical channel name as the virtual channel name. If you specify your own names for nameToAssignToChannel, you must use the names when you refer to these channels in other NI-DAQmx functions. If you create multiple virtual channels with one call to this function, you can specify a list of names separated by commas. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels. |
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| minVal | float64 | The minimum value, in units, that you expect to measure. | |||||||||
| maxVal | float64 | The maximum value, in units, that you expect to measure. | |||||||||
| units | int32 | The units to use to return the measurement.
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| thresholdLevel | float64 | The voltage level at which to recognize waveform repetitions. | |||||||||
| hysteresis | float64 | Specifies in volts a window below thresholdLevel. The input voltage must pass below thresholdLevel minus hysteresis before NI-DAQmx recognizes a waveform repetition. Hysteresis can improve measurement accuracy when the signal contains noise or jitter. | |||||||||
| customScaleName |
|
The name of a custom scale to apply to the channel. To use this parameter, you must set units to DAQmx_Val_FromCustomScale. If you do not set units to DAQmx_Val_FromCustomScale, you must set customScaleName to NULL. |
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. |