The Sync Source Event - Agilent Technologies 3458A User Manual

Figure 31. Sub-sampling example
Figure 32. Composite waveform
The Sync Source
In the preceding sub-sampling example, it was assumed that the multimeter
could somehow synchronize itself to the periods of the input waveform. This
Event
is the function of the sync source event. You can use either the EXT event
or the LEVEL event as the sync source event. The EXT sync source event
(specified by the SSRC EXT command) occurs on the negative-edge
transition on the multimeter's Ext Trig connector. This requires an external
pulse that is synchronous with the input signal. Figure 33 shows a typical
input signal and the required synchronizing signal. Notice in Figure 33 that
the synchronizing signal does not necessarily have to occur once for every
period of the input signal. It does, however, have to be synchronized in time
with the input signal.
Chapter 5 Digitizing 141