194ConceptsTrigger ConceptsTrigger ConceptsNOTE The trigger functions let you select the trigger settings for a sweep or measurement.When using a trigger source other than Free Run, the analyzer will begin a sweeponly with the selected trigger conditions are met. A trigger event is defined as thepoint at which your trigger source signal meets the specified trigger level andpolarity requirements (if any). In FFT measurements, the trigger controls when thedata is acquired for FFT conversion.Selecting a trigger1. Free Run TriggeringPressing this key, when it is not selected, selects free-run triggering. Free runtriggering occurs immediately after the sweep/measurement is initiated.Press Trigger, Free Run2. Video TriggeringThe Video trigger condition is met when the video signal (the filtered anddetected version of the input signal, including both RBW and VBW filtering)crosses the video trigger level. Video triggering triggers the measurement at thepoint at which the rising signal crosses the video trigger horizontal green line onthe display:Press Trigger, Video, Video, Trigger Level, −30, dBm. (If Video trigger has notalready been selected, you need to press Video a second time to get to the TriggerLevel function.)3. External TriggeringIn the event that you have an external trigger available that can be used tosynchronize with the burst of interest, connect the trigger signal to the rear of theanalyzer using either the Trigger 1 In or Trigger 2 In input connector. Itmight be necessary to adjust the trigger level by rotating the front panel knob orby entering the numeric value on the keypad.Press Trigger, External 1 or External 2, Trigger Level, and adjust as necessary.4. RF Burst Wideband TriggeringRF burst triggering occurs in the IF circuitry chain, as opposed to after the videodetection circuitry with video triggering. In the event video triggering is used, thedetection filters are limited to the maximum width of the resolution bandwidthfilters. Set the analyzer in RF burst trigger mode.Press Trigger, RF Burst.5. Line Triggering
