Agilent Technologies E4406A, User Manual

Page: 79 / 230

Chapter 3 79
Setting the Mode
Mode Setup
Trigger Keys
The Trigger key accesses the mode setup menu for the following
trigger sources. See
page 79 for an explanation of the trigger sources
listed below, as well as two additional trigger sources.
• RF Burst (Wideband)
• Video (IF Envlp)
•
Ext Front
•
Ext Rear
Pressing one of the trigger source keys will access the mode setup
menu. This menu is used to set the
Delay
,
Level
, and
Slope
for each
trigger source. Note that the actual trigger source is selected separately
for each measurement (under the
Meas Setup
key).
• Delay key. This key is used to set the delay time for trigger sources.
For trigger delay use positive values. For pre-trigger delay use
negative values. The range of the trigger delay is
−
500 ms to
+500 ms.
• Level key. For the
RF Burst (Wideband)
selection the level is relative
to the peak level of the RF signal (for the
RF Burst
trigger you will
enter a peak level value with a key labelled Peak Level, rather than
Level
). For the
Video
selection the level is the value, in dBm at the
RF input, that will cause the trigger. For the
Ext Front
and
Ext Rear
selections, the level range is
−
5 to +5 volts.
• Slope key. This key allows you to trigger off of the positive-going
edge (Pos) or the negative-going edge (
Neg
) of the trigger source
signal.
Other keys accessed under the
Trigger
key:
• Trig Holdoff key. Sets the period of time before the next trigger can
occur.
• Auto Trig key. Acts as a trigger timeout. If no trigger occurs by the
specified time, a trigger is automatically generated. When set to On
the instrument will take data when it receives a signal from the
current trigger source; if no signal is received in the expected time
period, the time period will default to the Free Run trigger default
time period. When set to Off (the default setting) data will only be
taken if a trigger has been set, and the Free Run trigger will not be
automatically activated.