Triggering 4
InfiniiVision Oscilloscopes User’s Guide 171
As you press the D+
or D– softkey (or rotate the Entry knob), the D+ and D– label for
the source channel is automatically set and the channel you select is shown in the
upper-right corner of the display next to “USB”.
If you have connected the oscilloscope’s analog source channels to the D+ and D-
signals: Adjust the trigger level for each connected analog channel to the middle of
the waveform by pressing the D+ or D- softkey, then turning the Trigger Level knob.
If you have connected the oscilloscope’s digital source channels to the D+ and D-
signals (this applies to MSO model oscilloscopes only): Press the [D15-D0] key and
select Thresholds to set an appropriate threshold level for the digital channels.
The value of the trigger level or digital threshold is displayed in the upper-right corner
of the display.
7 Press the Trigger: softkey to select where the USB trigger will occur:
• SOP (Start of Packet) — triggers at the Sync bit at the beginning of the packet.
• EOP (End of Packet) — triggers at the end of the SE0 portion of the EOP.
• RC (Reset Complete) — triggers when SE0 is > 10 ms.
• Suspend (Enter Suspend) — triggers when the bus is idle > 3 ms.
• Exit Sus (Exit Suspend) — triggers when exiting an idle state > 10 ms. This is used
to see the suspend/resume transition.
Bus Idle
SOP
SE0 portion of EOP
End of packet trigger