3- 6
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.
•
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.
•
TV
coupling is normally grayed-out, but is automatically selected when TV
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.
•
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.
Summary of Contents for 54621A
Page 4: ...iv ...
Page 10: ...Contents 6 ...
Page 11: ...1 Getting Started ...
Page 38: ...1 28 ...
Page 39: ...2 Front Panel Overview ...
Page 63: ...3 Triggering the Oscilloscope ...
Page 117: ...4 MegaZoom Concepts and Oscilloscope Operation ...
Page 171: ...5 Making Measurements ...
Page 222: ...5 52 Making Measurements Making overshoot and preshoot measurements ...
Page 223: ...6 Utilities ...
Page 239: ...7 Performance Characteristics ...
Page 250: ...7 12 Performance Characteristics Agilent 54620 series Performance Characteristics ...
Page 260: ...7 22 ...