CIChannelCollection.CreatePeriodChannel Method (String, String, Double, Double, CIPeriodStartingEdge, CIPeriodMeasurementMethod, Double, Int64, String)
- Updated2023-02-21
- 3 minute(s) read
CIChannelCollectionCreatePeriodChannel Method (String, String, Double, Double, CIPeriodStartingEdge, CIPeriodMeasurementMethod, Double, Int64, String)
Namespace: NationalInstruments.DAQmx
Assembly: NationalInstruments.DAQmx (in NationalInstruments.DAQmx.dll) Version: 20.7.40.49302
Syntax
public CIChannel CreatePeriodChannel( string counter, string nameToAssignChannel, double minimumValue, double maximumValue, CIPeriodStartingEdge edge, CIPeriodMeasurementMethod method, double measurementTime, long divisor, string customScaleName )
Public Function CreatePeriodChannel ( counter As String, nameToAssignChannel As String, minimumValue As Double, maximumValue As Double, edge As CIPeriodStartingEdge, method As CIPeriodMeasurementMethod, measurementTime As Double, divisor As Long, customScaleName As String ) As CIChannel
Parameters
- counter
- Type: SystemString
The names of the counters to use to create the virtual channel. - nameToAssignChannel
- Type: SystemString
The name to assign to the created channel. To use the physical channel name as the local virtual channel name, set this value to Empty. - minimumValue
- Type: SystemDouble
The minimum value expected from the measurement, in units. - maximumValue
- Type: SystemDouble
The maximum value expected from the measurement, in units. - edge
- Type: NationalInstruments.DAQmxCIPeriodStartingEdge
The edges between which to measure the period of the signal. - method
- Type: NationalInstruments.DAQmxCIPeriodMeasurementMethod
The method to use to calculate the period of the signal. - measurementTime
- Type: SystemDouble
The length of time to measure the period of a digital signal when method is HighFrequencyTwoCounter. Measurement accuracy increases with increased measurement time and with increased signal frequency. If you measure a high-frequency signal for too long, the count register might roll over, resulting in an incorrect measurement. - divisor
- Type: SystemInt64
The value by which to divide the input signal, when method is LargeRangeTwoCounter. The larger the divisor, the more accurate the measurement. However, too large a value might cause the count register to roll over, resulting in an incorrect measurement. - customScaleName
- Type: SystemString
The name of the custom scale to apply to the local virtual channel.
Return Value
Type: CIChannelThe newly created CIChannel.
Exceptions
| Exception | Condition |
|---|---|
| DaqException | The NI-DAQmx driver returned an error. |
Remarks
With the exception of devices that support multi-counter tasks, you can create only one CIChannel at a time with this function because a task can contain only one CIChannel. To read from multiple counters simultaneously, use a separate task for each counter.
This method creates a virtual channel for the physical channel name you specify.
If you do not provide a value for nameToAssignChannel, NI-DAQmx uses the physicalChannelName as the local virtual channel name. If you use nameToAssignChannel to create a name for the local virtual channel, you must use this name in other properties and methods.
The NI-DAQmx driver does not determine if the requested settings are possible until the task is verified. CreatePeriodChannel(String, String, Double, Double, CIPeriodStartingEdge, CIPeriodMeasurementMethod, Double, Int64, String) does not throw an exception for parameter values that are not compatible with your hardware or other settings in your task. To determine if all of the settings for a Task are valid, you must verify the task by starting the task, either with Start or by reading from or writing to the task, or by calling Control(TaskAction) with Verify.