Teledyne LabMaster 10 Zi Series Operator's Manual page 112

With DC coupling, all of the signal's frequency components are
coupled to the trigger circuit for high-frequency bursts.
4.
Touch inside the trigger Slope control and choose the direction of
the trigger voltage transition used for generating a particular
trigger event.
The selection is then shown to the right of the dialog as follows
for a Positive Slope selection on an Edge Trigger.
Edge trigger works on the selected edge at the chosen level. The slope
(positive or negative) is specified on the Trigger label permanently
shown to the lower-right of the grid.
5.
Level defines the source voltage at which the trigger circuit
generates an event (a change in the input signal that satisfies the
trigger conditions). The selected trigger level is associated with
the chosen trigger source. Note that the trigger level is specified
in volts and normally remains unchanged when the vertical gain
or offset is modified.
The Amplitude and Range of the trigger level have limits as
detailed in the datasheet specifications regularly maintained at
www.teledynelecroy.com.
Touch inside the Level data entry control and provide a value
using your preferred input control method. Additional
LM10Zi-GSM-E Rev A
Getting Started Guide
105