GW Instek AFG-2225 User Manual - Manual (Page 115)

MODULATION
115
Range Sweep time 1ms ~ 500s
Default time 1s
Marker Frequency
The marker frequency is the frequency at which the marker signal goes low
(The marker signal is high at the start of each sweep). The marker signal is
output from the Trigger OUT terminal on the rear panel. The default is 550
Hz.
Panel Operation 1. Press the SWEEP key.

2. Press F5 (More).
or 
3. Press F4 (Marker)
arkr 
4. Press F2 (ON/OFF) to toggle
the marker on or off.
 
5. Press F1 (Freq) to select the
marker frequency.
rq 
6. The Marker parameter will become highlighted
in the waveform display area.