Remote Spectrum Monitor™ MS27201A User Guide : Spectrum Monitor Measurements : Setting Sweep Parameters
Setting Sweep Parameters
Sweep parameters are set using the SWEEP Menu.
When the Continuous toggle is clicked, the instrument toggles between single sweep and continuous sweep. In single sweep setting, the instrument waits until SWEEP ONCE is clicked or another setting is selected.
Trace Points
The number of points sets the number of display points in the trace that are generated from the measurement data.
Sweep Limitations
With some spectrum monitors, the user has control over sweep time (the elapsed time of each sweep, also referred to as scan time). A monitor cannot be swept arbitrarily fast while maintaining its specified accuracy, but will have a sweep rate limitation depending upon the resolution bandwidth, video bandwidth, and frequency range selected. The sweep rate is not usually chosen by the user, but is determined by the frequency range swept divided by the sweep time. The limitation on sweep rate comes from the settling or response time of the resolution and video bandwidth filters. If a monitor is swept too quickly, the filters do not have time to respond, and the measurement is inaccurate. Under such conditions, the monitor display tends to have a “smeared” look to it, with the spectral lines being wider than normal and shifted to the right and at a lower amplitude than is correct.
Anritsu Remote Spectrum Monitor is designed to relieve the user from having to calculate the sweep speed or experiment to discover a sweep speed that yields accurate results. When changing the RBW and VBW, the sweep speed automatically changes to the fastest sweep speed that will yield accurate results. The sweep speed will be faster for a wide RBW or VBW and slower for a narrow RBW or VBW. Regardless of the minimum sweep time, the instrument will never sweep faster than the RBW and VBW settings will allow. The instrument is designed to ensure that no uncalibrated measurement conditions will occur.
Toggles between continuous sweep and single sweep. When the toggle is off, the instrument is in single sweep. In single sweep, the results of a sweep are displayed on the screen while the instrument awaits a trigger event to start a new sweep. The current state of the instrument is displayed in the status panel. With average/hold number (in TRACE menu) set to 1, or averaging is off, or no trace in trace average or hold, a single sweep is equivalent to a single measurement. A single sweep is taken after the trigger condition is met and the monitor stops sweeping once that sweep has completed. To take one more sweep without resetting the average count, click the SWEEP ONCE button. This sweep control is also available in the status panel.
The restart function restarts the current sweep or measurement from the start frequency.
When sweep is set to single sweep, SWEEP ONCE triggers a single measurement sweep.
When sweep is set to single sweep and trace type is set to average, rolling average, rolling max hold, or rolling min hold, SWEEP TO N triggers N consecutive measurement sweeps, where N is the number of averages set in the TRACE menu. Each time the button is clicked, it will restart the average count, then sweep N times. This button has no function when the instrument is in continuous sweep.
Sets the number of data points per sweep and displayed in each trace. The current value of points is displayed parenthetically, next to the sweep time in the lower-right corner of the display. Using more points provides greater resolution. Using fewer points compacts the data and decreases the time required to access a trace.
This button is available when the span is set to ZERO SPAN. Sets the sweep time.