Language Reference

VTH

VTH

Select slope of detected signal shape that triggers sweep.

Example

Description

 

Item

 

Description

Range

 

6 300

dB

Step Increment

1 major

vertical division during log mode. 1 major vertical division at top

 

 

graticule

line (.915 dB) during linear mode .

Preset

State

VTH 3DB

30 OUTPUT 723;"VTH;"

The VTH command determines the video trigger hysteresis. The hysteresis is the direction and magnitude of change in the detected video-signal level that triggers a sweep during the video trigger mode. Triggering occurs when the following conditions are met:

￿The video-signal level changes by the magnitude speci￿ed by the VTH command.

￿The video-signal level passes the video-trigger level speci￿ed by the VTL command.

When VTH speci￿es a positive value, the sweep triggers on the positive-going edge of the detected signal envelope. A negative value triggers a sweep on the negative-going edge.

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