CEMB USA N500 - Manual (Page 40)

6 - 8 FFT analyzer mode
When the trigger is enabled, the following settings become visible in the TRIGGER
SETUP page:
–
Channel
–
Threshold
2. Channel
This indicates on which channel (Ch1 or Ch2) to make the comparison between the signal
value and the threshold value in order to activate the acquisition.
N.B.
If just one of the two measuring channels is enabled, obviously choice of the trigger
channel is obligatory, hence it is forced automatically.
3. Threshold
This is the level which the signal must exceed (in a leading edge of the waveform) in order
for the acquisition to be started automatically. The selection of a suitable value is normally
one of the most delicate operations, but by using the N500 instrument it is considerably
simplified. The graph at the bottom of the page shows in real time the signal of the trigger
channel (in continuous line) and the current threshold (broken line). Hence the effect of
different values can be assessed immediately, thus making it easier to make a rapid choice
of the value considered most appropriate.