User`s guide

165
Using the Oscilloscope
The Scope Trigger Menu
Edge trigger mode
In the edge trigger mode, the oscilloscope triggers at a specified
voltage level on a rising or falling edge of one of the input channels. In
this mode you can specify which input is the trigger source, set a
trigger level voltage, and specify which edge to trigger on.
When you select edge trigger mode, additional fields appear for Source,
Level, Slope, Count, and Auto-Trig. These fields are discussed in the
following sections.
Pattern
Pattern trigger mode allows you to trigger the oscilloscope upon
entering or exiting a specified pattern of the trigger channels or by
specifying a pattern duration time or range. Each entry in the pattern
shown in the Pattern row shows the trigger condition of the input
above it in the Channel row.
You must set the trigger voltage level for each input you want to use in
the pattern. To set the voltage level, first set the Mode to Edge, then
set the level for each channel used in the Pattern. You can then return
to Pattern mode. The trigger level marker does not appear when
Pattern mode triggering is selected.
The pattern for each input may be specified as high (H), low (L), or
"don't care" (X). H, L, and X conditions are as follows:
• H-the voltage value of this input channel must be greater than the edge
trigger level of this input.
• L-the voltage level of this input channel must be less than the edge trigger
level of this input.
• X-is a "don't care" condition. The "don't care" means the associated input
channel will not be used in the pattern for the trigger qualifier. It does not
equate to "trigger on anything."