Phase difference

Phase difference
The Phase difference I/O determines the phase difference between its two input signals. The two input signals must have the same frequency and must have a large enough amplitude to be able to determine the phase.

The Phase difference I/O looks for the locations of all rising slopes in both input signals. It then determines the phase differences between corresponding rising slopes. The Phase difference I/O returns one value, which is the average phase difference between the measured signals. The Phase difference is determined with respect to the first connected signal and returned in degrees or in radians.

Properties and actions

To control the behavior of the Phase difference I/O, several properties are available. These can be accessed through a popup menu which is shown when the I/O is right clicked in the Object Tree. The properties can also be accessed through its settings window which is shown when the I/O is double clicked in the Object Tree. To open the Object tree, click the Show object tree Show object tree button.

Phase difference control

Swap inputs

The phase difference is determined with respect to the first connected signal (A). If the phase needs to be determined with respsect to the other signal (B), clicking the Swap inputs button will swap the two input signals and the phase will be determined with respect to the other signal.


The Status indicates the status of the phase difference determination. When the phase difference can be determined, the status will show the determined value. When the phase difference cannot be determined, the status shows the reason why not. This happens e.g. when the frequencies of the two input signals differ too much.

Levels A and B

The Phase difference I/O locates the rising slopes in the signal, around the mid level of the signal. This mid level can be set manually for both input signals (A and B) individually using Level A and Level B.

Hystereses A and B

To determine whether a slope is rising or falling, a hysteresis is used. This hysteresis determines how much the signal, with respect to the Level, must become larger in order to detect an edge. With a larger hysteresis, the detection is less sensitive for e.g. noise on the signal. If the hysteresis is too large, edges might be missed. This hysteresis can be set manually for both input signals (A and B) individually using Hysteresis A and Hysteresis B.

Auto detect levels / hystereses

When Auto detect levels / hystereses is enabled, the I/O tries to determine the the mid levels and a suitable hysteresis for both signals automatically.


The Unit determines whether the phase difference is given in degrees (°), in radians, in π radians or as cos(phi).

Common properties and actions

Related information

Duty cycle

The Duty cycle I/O determines the duty cycle of a signal.


The RMS I/O determines the True Root Mean Square value of a signal.


The FFT I/O is used for spectral analysis of a signal using a Fast Fourier Transformation


The EMI I/O creates an environment that can be used for EMI pre-compliance testing.