Triggering
Trigger Input Signal
This rear-panel connector is used in the following modes:
l
Triggered Sweep Mode: Press Trigger Setup softkey, then Source Ext, or execute
(sweep must be
enabled). When TTL edge of correct polarity is received on the Ext Trig connector, instrument outputs a single
sweep.
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Externally-Modulated FSK Mode: Press
Source
softkey or execute
(FSK must be enabled). When a
logic low level is present, carrier frequency is output. When a logic high level is present, hop frequency is output.
Maximum external FSK rate is 100 kHz.
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Triggered Burst Mode: Press
Trigger Setup
, then
Source Ext
, or execute
(burst must be ena-
bled). The instrument outputs a waveform with specified number of cycles (burst count) each time a trigger is
received from the specified trigger source.
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External Gated Burst Mode: Press
Gated
softkey or execute
with burst enabled. When external
gate signal is true, instrument outputs a continuous waveform. When external gate signal goes false, the current
waveform cycle completes and then instrument stops while remaining at voltage level corresponding to starting
burst phase. For noise, output stops as soon as the gate signal goes false.
Trigger Output Signal
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A "trigger out" signal is provided on the rear-panel
Ext Trig
connector (used with burst and sweep only). When
enabled, a TTL-compatible pulse with either a rising edge (default) or falling edge is output from this connector at
the beginning of the sweep or burst.
l
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Internal (immediate) or Timer trigger source:
instrument outputs a square wave with a 50% duty cycle
from the
Ext Trig
connector at the beginning of the sweep or burst. Waveform period equals specified sweep time
or burst period.
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External trigger source:
instrument disables "trigger out" signal. The rear-panel
Ext Trig
connector cannot be
used for both operations simultaneously (an externally-triggered waveform uses the same connector to trigger
sweep or burst).
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Bus (software) or manual trigger source:
instrument outputs a pulse (>1 μs pulse width) from
Ext Trig
con-
nector at beginning of each sweep or burst.
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Front Panel:
Enable sweep or burst. Then:
Agilent 33500 Series Operating and Service Guide
105