BNC 630 - Manual (Page 26)

21
5.8 Sweep Mode
Introduction
The Sweep mode continuously changes the frequency of a fixed amplitude sinusoid between a specified start frequency and a
specified stop frequency. The user can specify how long it takes for the sweep to reach the stop frequency. The frequency may be
stepped between the start and stop frequency linearly (i.e. the frequency is incremented over time by a constant value) or a
logarithmically (where the frequency is advanced logarithmically over time). A sweep direction (up or down) may also be specified.
The user can specify a Continuous or Triggered type sweep. In the Continuous mode, the sweep is restarted once the stop
frequency is reached. In the Triggered mode, the output waits at the start frequency until a trigger condition happens (Triggers can
come from a front panel keypress, a rising edge on the EXT Trigger connector, or an ASCII "T" on the terminal port). Once a
trigger occurs, the output frequency is swept to the stop frequency and the sweep is then reset to the start frequency. The unit then
awaits another trigger condition. For downward sweeps, the output frequency begins at the stop frequency and ends at the start
frequency.
Sweep Mode Parameters
The Sweep mode has the following front panel display:
Figure 5.8-1: Sweep mode display
1. Start Frequency
In this field enter the starting frequency for the sweep. You may enter from 0 Hz (DC) to 21.5000000 MHz in .01 Hz steps.
NOTE: You are not allowed to enter a start frequency that is greater than the stop frequency.
2. Stop Frequency
In this field enter the ending frequency for the sweep. You may enter from 0 Hz to 21.5000000 MHz in .01 Hz steps.
NOTE: You are not allowed to enter a stop frequency that is less than the start frequency.
3. Linear / Log sweep
In this field select how the sweep frequency is incremented during the sweep. A linear sweep means that the frequency is
incremented by a constant amount for a given amount of time. A log sweep means that the frequency is adjusted logarithmically
between the start and stop frequencies as the sweep progresses.
To set Linear type sweep, press 1 . To set Log type sweep, press 0 . Pressing any arrow key or rotating the wheel will toggle the
sweep type between Linear and Log.
St: 1,000,000.00 Hz Stp: 20,000,000.00 Hz
Linear | Cont | Up | Time: 60,000 mS -10.0 dBm
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