User`s guide

Chapter 3 91

Basic Digital Operation

Using Waveform Markers

Close-up of averaging

The ALC samples the waveform when the marker signal goes

high, and uses the average of the sampled waveform to set the

ALC circuitry.

Here the ALC samples during the on marker points (positive

polarity).

Marker

Example of Correct Use

Waveform: 1022 points

Marker range: 95-97

Marker polarity: Positive

This example shows a marker set to sample the waveform’s area of

highest amplitude. Note that the marker is set well before the

waveform’s area of lowest amplitude. This takes into account the

response difference between the marker and the waveform signal.

Pulse Unleveled

Example of Incorrect Use

Waveform: 1022 points

Marker range: 110-1022

Marker polarity: Positive

This example shows a marker set to sample the low part of the

same waveform, which sets the ALC modulator circuitry for

that level; this usually results in an unleveled condition for the

signal generator when it encounters the high amplitude of the

pulse.

MarkerMarker