10-28
IM 701310-01E
Explanation
There are three statistical processing types: normal, cycle, and history.
The DL9000 calculates statistics on the same measurement items as those of automated
measurement of waveform parameters described in section 10.2. The DL9000 calculates
and displays the following statistics on the selected automatically measured items. For
example, if you select CH1 P-P for the automatically measured item, statistics such as
the maximum, minimum, mean, and standard deviation values as well as the number of
measured values used to calculate the statistics appear at the bottom of the screen.
Max
Maximum value
Min
Minimum Value
Mean
Mean value
σ
Standard deviation
Cnt
The number of measured values that statistics were calculated for
The DL9000 can display the statistical results of two automatically measured items. If
three or more automatically measured items are selected, the DL9000 displays the first
two items in ascending order by channel number and in the order that the items appear
in the automatic measurement item selection dialog box (Max, Min, ...,
Δ
T, Delay).
Example 1: If CH1: Max, High, CH2: Max, Min, CH3: Max, and Min are selected, the DL9000
displays CH1: Max and CH1: High
Example 2: If CH1: Max, CH2: Max, Min, CH3: Max, and Min are selected, the DL9000 displays
CH1: Max and CH2: Max
You can view the statistics of other items in the following way.
• Load the items into a PC using the communication function.
• Save the statistics as automatically measured waveform items (see section 13.10)
and load the data into a PC.
Normal Statistical Processing
While acquiring signals, the DL9000 calculates statistics on the signals that it has
acquired so far. The number of measured values that statistics were calculated for,
expressed as Cnt, corresponds to the number of signals that the DL9000 has acquired
up to that point. If you add an automatically measured item to the statistical calculation,
the Cnt value is reset to 1 regardless of whether or not the DL9000 is acquiring signals.
Cycle Statistical Processing
In cycle statistical processing, the DL9000 determines periods in order from the oldest
data of the displayed waveform, measures the selected automatically measured items
on the data within each period, and calculates statistics. The method of determining
the period is the same as the method for determining the normal waveform period. The
period of the specified signal is applied to all measurement source waveforms.
The following parameters cannot be selected.
Freq (average frequency) 1/Freq (average period), Count (edge count),
Δ
T, and Delay
Statistical Processing on History Data
In history statistical processing, the DL9000 measures automatically measured items
on the waveform acquired using the history memory function. The DL9000 calculates
statistics from the oldest waveform. Statistics are calculated on the waveforms displayed
in ShowMap.
Notes about Statistical Processing
All soft keys except the Abort soft key are disabled while statistical processing is in
progress. The
START/STOP
key can be used for normal statistical processing.
10.3 Calculating Statistics on the Measured Waveform Parameter Values
