Keysight E6640A, Руководство пользователя и программиста по приложениям измерений

Страница: 1574 / 2870

11 Occupied Bandwidth Measurement
Sweep/Control
Video (IF Envelope)
Pressing this key, when it is not selected, selects the video signal as the trigger. The Video trigger condition
is met when the video signal (the filtered and detected version of the input signal, including both RBW and
VBW filtering) crosses the video trigger level.
When the detector selected for all active traces is the average detector, the video signal for triggering
does not include any VBW filtering.
The video trigger level is shown as a labeled line on the display. The line is displayed as long as video is the
selected trigger source.
Pressing this key, when it is already selected, accesses the video trigger setup functions.
Key Path
Trigger
Example TRIG:SOUR VID Swept SA measurement
TRIG:<meas>:SOUR VID Measurements other than Swept SA
Notes Log Plot and Spot Frequency measurements do not support Video Trigger
Dependencies Video trigger is allowed in average detector mode.
State Saved Saved in instrument state
Status Bits/OPC
dependencies
The Status Operation Register bit 5 "Waiting for Trigger" is set at the same time as the Sweeping or
Measuring bit is set. It is cleared when the trigger actually occurs (that is, after the trigger event
occurs and all the applicable trigger criteria have been met). A corresponding pop-up message
("Waiting for trigger") is generated if no trigger signal appears after approximately 2 sec. This
message goes away when a trigger signal appears.
Backwards Compatibility
Notes In the past, the Average detector was not available when Video triggering was on, and consequently,
functions that set the detector to average (such as Marker Noise or Band/Intvl Power) were not
available when the video trigger was on. Similarly, Video triggering was not available when the
detector was Average. In the X-Series, these restrictions are removed.
Initial S/W Revision Prior to A.02.00
Trigger Level
Sets a level for the video signal trigger. When the video signal crosses this level, with the chosen slope,
the trigger occurs. This level is displayed with a horizontal line only if Video is the selected trigger source.
Key Path
Trigger, Video
Remote Command :TRIGger[:SEQuence]:VIDeo:LEVel <ampl>
:TRIGger[:SEQuence]:VIDeo:LEVel?
Example TRIG:VID:LEV –40 dBm
Notes When sweep type = FFT, the video trigger uses the amplitude envelope in a bandwidth wider than the
FFT width as a trigger source. This might often be useful, but does not have the same relationship
between the displayed trace and the trigger level as in swept triggering.
Amplitude Corrections are not taken into account by the Video Trig Level. For example, if you have
given yourself effective gain with an amplitude correction factor, the Video Trigger will not fire until
1574 W-CDMA & HSPA Measurement Applications Reference