Keysight Technologies N5171B EXG, User Manual

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110 Keysight EXG and MXG X-Series Signal Generators User’s Guide
Optimize Performance
Using Free Run, Step Dwell, and Timer Trigger
Using Free Run, Step Dwell, and Timer Trigger
Free Run , Step Dwell (time), and Timer Trigger can be used to adjust the time spent at any point in
a Step Sweep or a List Sweep. There are two possible measurement combinations:
Free Run with Step Dwell time ( Figure 4-27 on page 111 ) the signal generator waits for the signal
to settle and then waits for the Step Dwell time, then it jumps to the next frequency point. In
addition, the time to complete the entire sweep can vary. There is always a minimum value of Step
Dwell for each frequency point. The minimum Step Dwell timing for any point is fixed at a value of
100 us. The time between frequency points is the sum of the settling time, plus the Step Dwell time.
The settling time is dependent on frequency, amplitude, band crossings, and other factors, so the
time between frequency points can vary.
Timer Trigger instead of Free Run ( Figure 4-27 on page 111 ) the signal generator generates
equally spaced triggers, and it moves to the next point at each trigger. This has the advantage that
the time between points is consistent and the overall sweep time is consistent. But, if the trigger is
too fast, the signal may not have time to settle before jumping to the next point.
Understanding Free Run, Step Dwell, and Timer Trigger Setup
If the signal is to be settled for a minimum specific time at each point and it is not important if the
point to point time is consistent, use Free Run and Set Dwell time.
If the signal’s point to point time requires consistency but the specific settling time at each point
can vary, then use the Timer Trigger. Avoid using too fast of a sweep which does not allow the
signal generator to settle.
If the signal needs to be settled for a specific minimum time
and consistent point to point time is
required, then you should set the Timer Trigger to be the sum of the switching time (900 us or 5 ms,
depending on options) plus the minimum settled time that is needed to make the measurement.
If the measurement requires external equipment synchronization, consider using hardware triggers.