When the asynchronous signal is exported with a custom export rate, the values get adjusted the following way.
For example, we want to export the green signal with an adjusted export rate of 1 Hz, which means that we get a sample value every second.
1.)old HOLD method: The method outputs the value of the last stored sample. For a timestamp of 2 s, the value of a selected sample is exported.
2. new HOLD method: the new HOLD method within the resampler got adjusted with additional approximation error:
e = 1/exportRate * 10^-3
Meaning that the new HOLD method also checks the samples in the range of the error. For a timestamp of 2 s, the value of a selected sample is exported.
3.) Linear type: With the new resampler option additional more complex and accurate method can be used, like linear interpolation. The method performs a linear interpolation between two nearest samples to the time stamp. For a timestamp of 2 s, the interpolated value is exported.
4.) Alias-free method: The most complex method and the one which produces the most accurate results is the Alias-free method. It resamples the data by filtering it with an anti-aliasing filter. The properties of the filter used can be set in the Options -> Settings -> Advanced -> Export. This method can only be used to export data from Synchronous Scalar channels.