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3.4.5 Acquisition with Re-Triggering
A digitizer acquires a trace of N samples/channel for a single acquisition. Re-Trigger mode can also
be set to automatically acquire R traces, containing N*R samples/channel of data, without additional
software intervention.
The Re-Trigger setting can be used for Post-Trigger and Delayed- Trigger modes, with different
limitations on the spacing between trigger events in each mode. Trigger events arriving too close to
the previous instance will be ignored by the digitizer.
•
In Post-Trigger mode, the minimum spacing between trigger events is N+8
•
In Delayed-Trigger mode, the minimum spacing between trigger events is (N+D)+8, where D
is the number of the delayed setting
Figure 3-9: Re-Trigger Mode Acquisition
3�4�6 Data Average Mode (Post-Trigger and Delayed- Trigger only)
In normal post-trigger mode acquisition, N samples/channel data are generated for a single trigger
event. In Re-trigger mode (See “Acquisition with Re-Triggering” on page 17.), a total of N * R sam-
ples/channel data is generated for R trigger events, that is, R traces (A trace contains N samples/
channel). In Data Average Mode, only N samples/channel data are generated for R trigger events.
The single trace data (N samples/channel) is the average of the R traces sample by sample.
The output data format is 16-bit or 32-bit signed integer, software selectable. When higher
measurement accuracy is desired, data average mode with 32 bit data output can improve the
resolution. According to oversampling practice, the retrigger times R required to get n bits of
additional resolution is R = 4^n. Please note that in order for data average mode to work properly,
components of signal of interest, such as period and magnitude, should be consistent during
conversion.
