Creates channel(s) that use a Wheatstone bridge to measure pressure. Use this instance with sensors whose specifications provide a polynomial to convert electrical values to physical values. When you use this scaling type, NI-DAQmx requires coefficients for a polynomial that converts electrical values to physical values (forward), as well as coefficients for a polynomial that converts physical values to electrical values (reverse). If you only know one set of coefficients, use the DAQmx Compute Reverse Polynomial Coefficients node to generate the other set.
Specify different values for units and physical units if the sensor specifications provide physical values in one unit, but you want NI-DAQmx to scale data to a different unit.
task in specifies the task to which to add the virtual channels this node creates. If you do not specify a task, NI-DAQmx creates a task for you, and adds the virtual channels this node creates to that task.
error in describes error conditions that occur before this node runs. This input provides standard 'error in' functionality.
physical channels specifies the names of the physical channels to use to create virtual channels. The DAQmx physical channel constant lists all physical channels on devices and modules installed in the system.
You can also wire a string that contains a list, or range of physical channels, to this input. If you have an array of physical channels, use the DAQmx Flatten Channel String node to convert the array to a list.
name to assign specifies a name to assign to the virtual channel this node creates. If you do not wire a value to this input, NI-DAQmx uses the physical channel name as the virtual channel name.
If you use this input to provide your own names for the virtual channels, you must use the names when you refer to these channels in other NI-DAQmx nodes, such as the source input of the DAQmx Trigger node.
If you create multiple virtual channels with one DAQmx Create Virtual Channel node, you can specify a comma-separated list of names to assign to the virtual channels. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.
units specifies in which unit to return pressure measurements from the channel.
Pounds per square inch.
|From Custom Scale||
Units a custom scale specifies. If you select this value, you must wire a custom scale name to the custom scale name input.
custom scale name specifies the name of a custom scale for the channel.
measurement range specifies the minimum and maximum values you expect to measure.
maximum value specifies in units the maximum value you expect to measure.
minimum value specifies in units the minimum value you expect to measure.
bridge information specifies information about the bridge configuration and measurement.
bridge configuration specifies the Wheatstone bridge configuration connected to the channel.
Four active sensing elements in the bridge.
Two active sensing elements in the bridge.
One active sensing element in the bridge.
voltage excitation source specifies the source of excitation.
Use an excitation source other than the built-in excitation source of the device. If you select this value, you must use the voltage excitation value input to specify the amount of excitation.
Use the built-in excitation source of the device. If you select this value, you must use the voltage excitation value input to specify the amount of excitation.
Supply no excitation to the channel.
voltage excitation value specifies in volts the amount of excitation supplied to the sensor. Refer to the sensor documentation to determine appropriate excitation values.
nominal bridge resistance specifies in ohms the resistance of the bridge while not under load.
scaling information specifies how to scale electrical values from the sensor to physical units.
forward coeff is an array of coefficients, for the polynomial, that converts electrical values to physical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
reverse coeff is an array of coefficients, for the polynomial, that converts physical values to electrical values. Each element of the array corresponds to a term of the equation. For example, if index three of the array is 9, the fourth term of the equation is 9x^3.
electrical units specifies from which electrical unit to scale data. Select the same unit that the sensor data sheet, or calibration certificate, uses for electrical values.
Volts per volt.
Millivolts per volt.
physical units specifies to which physical unit to scale electrical data. Select the same unit that the sensor data sheet or calibration certificate uses for physical values.
Pounds per square inch.
task out is a reference to the task after this node runs. The task contains any newly created virtual channels. If you did not wire a value to task in, NI-DAQmx automatically creates the task this output refers to.
error out contains error information. If error in indicates that an error occurred before this node ran, error out contains the same error information. Otherwise, error out describes the error status that this node produces.
Where This Node Can Run:
Desktop OS: Windows
FPGA: LabVIEW NXG does not support FPGA devices
Web Server: Not supported in VIs that run in a web application