User manual

5-18 Return to Section Topics 3390-900-01 Rev. C / January 2009
Section 5: Waveform Output Operations Model 3390 Arbitrary Waveform Generator User’s Manual
discrete frequency points is calculated by the waveform generator according to the sweep time
specified. The default sweep time is 1 second, and the range is from 1 ms to 500 s.
Marker frequency
Marker frequency controls the sync signal that is output from the front panel Sync connector. The
default marker frequency is 500 Hz and the range of the marker frequency is dependent on stop
frequency setting or frequency span setting. The marker frequency must be less than or equal to
the maximum output frequency.
Performing a sweep with an enabled marker frequency (selected in Hz), starts the sync signal
at transistor-transistor logic (TTL) "high" at the beginning of the sweep and turns it to "low" at the
marker frequency. For sweeps with Marker Off, the Sync signal is a square waveform with a 50%
duty cycle. The Sync signal is at TTL "high" at the beginning of a sweep and turns to "low" at
the midpoint of the sweep. The frequency of the Sync signal is the reciprocal of the specified
sweep time.
Trigger source
The waveform generator outputs a single sweep when it receives a trigger signal, and it continues
delivering the same type of waveform with the start frequency before it receives the next trigger
and sends another sweep.
Trigger source can be internal, external, or manual. The default is internal.
The trigger sources perform as follows:
• Internal trigger source: The waveform generator continuously delivers sweeps at the
specified sweep time.
• External trigger source: The trigger signal is a TTL pulse with specified polarity applied to
the Trig In/Out connector on the rear panel. The trigger period cannot be less than 1 ms plus
the specified sweep time.
• Manual trigger source: The waveform generator sends out a sweep each time the Trigger
key on the front panel is pressed.
Trigger out signal
A trigger out signal is delivered at the Trig In/Out, FSK / Burst connector on the rear panel.
Trigger out signals perform as follows:
• Internal trigger source: A square waveform with 50% duty cycle is delivered at the Trig Out
connector with the sweep output.
• Manual trigger source: A pulse is delivered (with pulse width > 1 μs) at the Trig Out
connector at the beginning of each sweep.
To set up frequency sweep:
1. Select the carrier waveform (Sine, Square, Ramp, or Arb). Follow the instructions for
setting up that specific waveform as given in this publication. Refer to Section 4, Setup
Basics for assistance.
2. Press the Sweep key to access the sweep menu.
3. Press the soft key under Linear / Log to choose between linear or logarithmic mode
(Figure 5-16).