3 Using the Scope Functions  
46 Agilent U1602B/U1604B User’s and Service Guide 
• Slope
Press F3 on page 1/2 to select rising edge  or falling edge  . 
The selected slope is displayed at the trigger status line at the right 
of the display.
•Coupling
Press F2 on page 2/2 to select trigger coupling:
• DC  coupling allows DC and AC signals to pass through the trigger 
path.
• AC  coupling allows AC signals to pass through the trigger path 
and filter DC offset voltage from the trigger waveform. The 
coupling cutoff frequency is less than 1 Hz. The AC coupling is 
useful to get a stable edge trigger when the waveform has a large 
DC offset.
• HF Rejection coupling places a 50 kHz low- pass filter in the 
trigger path to remove high frequency components from the trigger 
waveform. The HF- Rej is useful to observe low frequency signals 
while getting rid of high frequency noise from trigger path.
• LF Rejection coupling places a 30 kHz high- pass filter in series 
with the trigger waveform to remove any unwanted low frequency 
components from the trigger waveform. This LF- Rej is useful to 
obtain a stable edge trigger when your waveform contains low 
frequency noise.
• Noise Rejection coupling is three times the DC coupled limits. The 
Noise- Rej provides additional hysteresis to the trigger circuitry.
• Level 
Press F3 on page 2/2 to select the types of trigger level adjustment. 
• Manual trigger level allows you to change the trigger level by 
turning the rotary switch. The value of the trigger level is 
displayed under the Level column.
• TTL trigger level sets the trigger level to recognize the High/Low 
condition in a TTL signal automatically.