Frequency Sweep Linear / Exponential

Macro: SweepMode

This pair of radio buttons control the shape of the sweep. When Linear is active, the total End minus Start frequency range is simply divided by the duration to give a fixed number of Hz per second (or per sample).

In Exponential mode, the frequency at each sample time is the value of the prior frequency, times a constant. Thus, the higher the frequency, the faster the motion. This gives a fixed number of octaves per second, rather than Hz per second.

This is useful for testing many real-world systems which exhibit an exponential response; it is necessary to move the driving frequency more slowly at lower frequencies to capture response details with the same resolution as a faster sweep at higher frequencies.

Macro Notes:

L.1.SweepMode=Lin sets the Left Stream 1 Sweep Mode to Linear, while Exp sets it to Exponential. Alternatively, you can use numeric values, variables, or expressions equal to 0 and 1 in place of 'Lin' and 'Exp', respectively.

See also Frequency Sweep, Waveform Stream Controls