User`s guide

Chapter 3 105
Basic Digital Operation
Triggering Waveforms
Setting the Polarity of an External Trigger
Gated Mode
The selections available with the gate active parameter refer to the low and high states of an external
trigger signal. For example, when you select High, the active state occurs during the high of the
trigger signal.
ARB Formats When the active state occurs, the PSG stops the waveform file playback at the last
played sample point, and restarts the playback at the next sample point when the
inactive state occurs.
Real- Time Custom When the active state occurs, the PSG transmits the data pattern. When the
inactive state occurs, the transmission stops at the last transmitted symbol, and
restarts at the next symbol when the active state occurs.
Continuous, Single, or Segment Advance Modes
The
Ext Polarity Neg Pos softkey selections refer to the low (negative) and high (positive) states of an
external trigger. With Neg selected (the default), the PSG responds during the low state of the trigger
signal.
Using Gated Triggering
Gated triggering enables you to define the on (playback) and off states of a modulating waveform.
This example uses the factory supplied segment, SINE_TEST_WFM.
1. Connect the output of a function generator to the signal generator’s rear- panel PATTERN TRIG
IN, as shown in the following figure.
This connection is applicable to all external triggering methods. The optional oscilloscope
connection enables you to see the effect that the trigger signal has on the RF output.
2. Preset the signal generator.