Triggers 11
Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide 171
 
You can also adjust the trigger level using the touchscreen. See “Access the 
Trigger Menu, Change the Trigger Mode, and Open the Trigger Level Dialog" on 
page 57.
You can push the Trigger Level knob to set the level of all displayed analog 
channels to the waveform's 50% value. If AC coupling is used, pushing the Trigger 
Level knob sets the trigger level to about 0 V.
When High and Low (dual) trigger levels are used (as with the Rise/Fall Time and 
Runt triggers, for example), pushing the Level knob toggles between high and low 
level adjustment.
The position of the trigger level for the analog channel is indicated by the trigger 
level icon   (if the analog channel is on) at the far left side of the display. The 
value of the analog channel trigger level is displayed in the upper-right corner of 
the display.
The trigger level for a selected digital channel is set using the threshold menu in 
the Digital Channel Menu. Press the [Digital] key on the front panel, then press the 
Thresholds softkey to set the threshold level (TTL, CMOS, ECL, or user defined) for 
the selected digital channel group. The threshold value is displayed in the 
upper-right corner of the display.
The line trigger level is not adjustable. This trigger is synchronized with the power 
line supplied to the oscilloscope.
Forcing a Trigger
The [Force Trigger] key causes a trigger (on anything) and displays the acquisition.
This key is useful in the Normal trigger mode where acquisitions are made only 
when the trigger condition is met. In this mode, if no triggers are occurring (that is, 
the "Trig'd?" indicator is displayed), you can press [Force Trigger] to force a trigger 
and see what the input signals look like.
In the Auto trigger mode, when the trigger condition is not met, triggers are forced 
and the "Auto?" indicator is displayed.
You can also change the trigger level of all channels by pressing [Analyze] > Features and 
then selecting Trigger Levels.