Agilent Technologies 42A ユーザーズマニュアル
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Triggering the Oscilloscope
To select trigger Coupling
To select trigger Coupling
1 Press the
Mode/Coupling
key.
2 Press the
Coupling
softkey, then select
DC, AC,
or
LF Reject
coupling.
•
DC coupling allows dc and ac signals into the trigger path.
•
AC coupling places a high-pass filter (3.5 Hz for 54620-series analog channels,
10 Hz for 54640-series analog channels, and 3.5 Hz for all External trigger
inputs) in the trigger path removing any DC offset voltage from the trigger
waveform. Use AC coupling to get a stable edge trigger when your waveform
has a large DC offset.
10 Hz for 54640-series analog channels, and 3.5 Hz for all External trigger
inputs) in the trigger path removing any DC offset voltage from the trigger
waveform. Use AC coupling to get a stable edge trigger when your waveform
has a large DC offset.
•
LF (low frequency) Reject coupling places a 50-kHz high-pass filter in series
with the trigger waveform. Low frequency reject removes any unwanted low
frequency components from a trigger waveform, such as power line
frequencies, that can interfere with proper triggering. Use this coupling to
get a stable edge trigger when your waveform has low frequency noise.
with the trigger waveform. Low frequency reject removes any unwanted low
frequency components from a trigger waveform, such as power line
frequencies, that can interfere with proper triggering. Use this coupling to
get a stable edge trigger when your waveform has low frequency noise.
•
TV coupling is normally grayed-out, but is automatically selected when TV
trigger is enabled in the Trigger More menu.
trigger is enabled in the Trigger More menu.
To select Noise Reject and HF Reject
1 Press the
Mode/Coupling
key.
2 Press the
Noise Rej
softkey to select noise reject or press the
HF Reject
softkey to select high frequency reject.
•
Noise Rej adds additional hysteresis to the trigger circuitry. When noise reject
is on, the trigger circuitry is less sensitive to noise but may require a greater
amplitude waveform to trigger the oscilloscope.
is on, the trigger circuitry is less sensitive to noise but may require a greater
amplitude waveform to trigger the oscilloscope.
•
HF Reject adds a 50 kHz low-pass filter in the trigger path to remove high
frequency components from the trigger waveform. You can use HF Reject to
remove high-frequency noise, such as AM or FM broadcast stations or from
fast system clocks, from the trigger path.
frequency components from the trigger waveform. You can use HF Reject to
remove high-frequency noise, such as AM or FM broadcast stations or from
fast system clocks, from the trigger path.