150 Keysight InfiniiVision 2000 X-Series Oscilloscopes User's Guide
11 Trigger Mode/Coupling
2 In the Trigger Mode and Coupling Menu, press the Coupling softkey; then, turn
the Entry knob to select:
• DC coupling — allows DC and AC signals into the trigger path.
• AC coupling — places a 10 Hz high-pass filter in the trigger path removing
any DC offset voltage from the trigger waveform.
The high-pass filter in the External Trigger input path is 50 Hz for all models.
Use AC coupling to get a stable edge trigger when your waveform has a
large DC offset.
• LF (low frequency) Reject coupling — adds a high-pass filter with the 3-dB
point at 50 kHz in series with the trigger waveform.
Low frequency reject removes any unwanted low frequency components
from a trigger waveform, such as power line frequencies, etc., that can
interfere with proper triggering.
Use LF Reject 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 Menu.
Note that Trigger Coupling is independent of Channel Coupling (see “To specify
channel coupling" on page 65).
Pass
Band
50 kHz
0 dB
3 dB down point
DC