DAQmxCreateAIStrainGageChan
int32 DAQmxCreateAIStrainGageChan (TaskHandle taskHandle, const char physicalChannel[], const char nameToAssignToChannel[], float64 minVal, float64 maxVal, int32 units, int32 strainConfig, int32 voltageExcitSource, float64 voltageExcitVal, float64 gageFactor, float64 initialBridgeVoltage, float64 nominalGageResistance, float64 poissonRatio, float64 leadWireResistance, const char customScaleName[]);
Purpose
Creates channel(s) to measure strain 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
|
const char []
|
The names of the physical channels to use to create virtual channels. You can specify a list or range of physical channels. |
|
nameToAssignToChannel
|
const char []
|
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. |
|
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.
| Name |
|
Description |
|
DAQmx_Val_Strain
|
|
Strain |
|
DAQmx_Val_FromCustomScale
|
|
Units specified by a custom scale. Use customScaleName to specify a custom scale. |
|
|
strainConfig
|
int32 |
The strain gage bridge configuration.
| Value |
|
Description |
|
DAQmx_Val_FullBridgeI
|
|
Four active gages with two pairs subjected to equal and opposite strains. |
|
DAQmx_Val_FullBridgeII
|
|
Four active gages with two aligned with maximum principal strain and two Poisson gages in adjacent arms. |
|
DAQmx_Val_FullBridgeIII
|
|
Four active gages with two aligned with maximum principal strain and two Poisson gages in opposite arms. |
|
DAQmx_Val_HalfBridgeI
|
|
Two active gages with one aligned with maximum principal strain and one Poisson gage. |
|
DAQmx_Val_HalfBridgeII
|
|
Two active gages with equal and opposite strains. |
|
DAQmx_Val_QuarterBridgeI
|
|
Single active gage. |
|
DAQmx_Val_QuarterBridgeII
|
|
Single active gage and one dummy gage. |
|
|
voltageExcitSource
|
int32 |
The source of excitation.
| Value |
|
Description |
|
DAQmx_Val_Internal
|
|
Use the built-in excitation source of the device. You must use voltageExcitVal to specify the amount of excitation. |
|
DAQmx_Val_External
|
|
Use an excitation source other than the built-in excitation source of the device. You must use voltageExcitVal to specify the amount of excitation. |
|
DAQmx_Val_None
|
|
Supply no excitation to the channel. You cannot use this value if the sensor requires excitation. |
|
|
voltageExcitVal
|
float64 |
The amount of excitation, in volts, that the sensor requires. |
|
gageFactor
|
float64 |
The sensitivity of the strain gages and relates the change in electrical resistance to the change in strain. Each gage in the bridge must have the same gage factor. Refer to the sensor documentation to determine this value. |
|
initialBridgeVoltage
|
float64 |
The bridge output voltage in the unloaded condition. NI-DAQmx subtracts this value from any measurements before applying scaling equations. Perform a voltage measurement on the bridge with no strain applied to determine this value. |
|
nominalGageResistance
|
float64 |
The resistance, in ohms, of the gages in an unstrained position. Each gage in the bridge must have the same nominal gage resistance. The resistance across arms of the bridge that do not have strain gages must also be the same as the nominal gage resistance. Refer to the sensor documentation to determine this value. |
|
poissonRatio
|
float64 |
The ratio of lateral strain to axial strain in the material in which you measure strain. |
|
leadWireResistance
|
float64 |
The amount, in ohms, of resistance in the lead wires. Ideally, this value is the same for all leads. |
|
customScaleName
|
const char []
|
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. |