Source Tab

This tab is used to setup one or more output signals from the acquisition front end hardware to one or more shakers.

WARNING: This option only functions with connected to front end hardware that can receive source signals from the ME'scope Acquisition software.

Source Tab Showing Burst Random Output from Source Channel 1.

To setup a Source signal,

Random & Chirp Signals

Random & Chirp source signals are synthesized over the Frequency Span selected in the Sampling tab, and output to the front end hardware.

Frequency Range

Defines the frequency range of all Source signals as percentages of the Minimum & Maximum percentages of the Frequency Span chosen on the Sampling tab.

Burst Width

Defines the percentage of the sampling window samples over which the synthesized random or chirp signals are non-zero. The remainder of the source samples are output as zeros. Outputting a source signal with zeros in it has the effect of removing all forces from the test article. Hence the acquired structural responses will decay to zero.

A signal that decays within the sampling window is completely contained within the window. Therefore its spectrum is leakage-free and doesn't require special windowing to reduce leakage effects.
The amount of damping in the test article determines how quickly its structural responses will decay to zero within the sampling window

To determine the required burst width,

If the response signals decay essentially to zero within the window (as shown below), the signals are completely contained within the sampling window, and no special time domain windowed is required in order to reduce leakage in their spectra.

Correct Burst Random Output Showing Responses Contained In The Window.