Finds the first level-crossing location in a signal.
The edge or slope in which the node detects the trigger.
This input accepts a ring or a 1D array of rings. This input accepts a 1D array of rings when signal is a 1D array of waveforms or a 2D array of double-precision, floating-point numbers.
Name | Value | Description |
---|---|---|
falling | 0 | Detects a trigger on the falling edge, or negative slope. |
rising | 1 | Detects a trigger on the rising edge, or positive slope. |
Default: rising
A Boolean specifying whether the history, or internal state, of the node has to be reset.
True | Resets the internal state of the node. |
False | Does not reset the internal state of the node. |
This input accepts a Boolean or a 1D array of Booleans. This input accepts a 1D array of Booleans when signal is a 1D array of waveforms or a 2D array of double-precision, floating-point numbers.
The internal state contains the final state of the input signal. This node uses this as the initial state the next time this node is called.
Default: False
The threshold value that the input signal must cross before a trigger is detected.
This input accepts a double-precision, floating-point number or a 1D array of double-precision, floating-point numbers. This input accepts a 1D array of double-precision, floating-point numbers when signal is a 1D array of waveforms or a 2D array of double-precision, floating-point numbers.
Default: 0
Amount above or below the threshold level through which the input signal must pass before a trigger level crossing is detected.
This input accepts a double-precision, floating-point number or a 1D array of double-precision, floating-point numbers. This input accepts a 1D array of double-precision, floating-point numbers when signal is a 1D array of waveforms or a 2D array of double-precision, floating-point numbers.
Using Hysteresis to Detect A Trigger Level Crossing
Trigger hysteresis is used to prevent noise from causing a false trigger. For a rising edge trigger slope, the signal must pass below level - hysteresis before this node detects a trigger level crossing. For a falling edge trigger slope, the signal must pass above level + hysteresis before this node detects a trigger level crossing.
Default: 0
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Default: No error
Sample period of the time-domain signal in seconds.
Set this input to 1/fs, where fs is the sampling frequency of the time-domain signal.
This input is available only if you wire a 1D array of double-precision, floating-point numbers or a 2D array of double-precision, floating-point numbers to signal.
Default: 1
Mode in which to retrieve the trigger location.
This input accepts a ring or a 1D array of rings. This input accepts a 1D array of rings when signal is a 1D array of waveforms or a 2D array of double-precision, floating-point numbers.
Name | Value | Description |
---|---|---|
Index | 0 | Retrieves the trigger locations as array indexes. |
Time | 1 | Retrieves the trigger locations as time in seconds. |
Algorithm for Calculating the Trigger Location by Time
This node computes Time by the following equation:
Time = Index * dt
When the input signal is a waveform or a 1D array of waveforms, dt is contained in the input signal.
Default: Index
The index or time of the detected trigger.
This output can return a double-precision, floating-point number or a 1D array of double-precision, floating-point numbers.
Error information.
The node produces this output according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Where This Node Can Run:
Desktop OS: Windows
FPGA: Not supported
Web Server: Not supported in VIs that run in a web application