User manual

21
Horizontal System
mum amount of data. Each column in the signal window
displays up to 40 detected data values (limited by proces-
sor performance). How much data is currently displayed
depends on the displayed time window and the current
sampling rate. If peak detection is activated, each co-
lumn displays up to 20 pairs of min/max values. The me-
mory depth always corresponds to the maximum acquisi-
tion memory. The displayed sampling rate is identical with
the current sampling rate. Peak detection is used if the dis-
played time window contains more data than 40 * signal
window columns in the acquisition memory or min/max
data in the acquisition memory.
5.3.8.3 AUTOMATIC
This function is the default setting and offers the best
compromise between maximum repeat rate and maximum
sampling rate (selection of memory depth). Each column in
the signal window displays up to 10 captured data values.
How much data is currently displayed depends on the dis-
played time window and the current sampling rate. When
peak detection is activated, each column displays up to
5 pairs of min/max values. The memory depth is at least
twice as much as the storage capacity set for the maxi-
mum repeat rate (limited by the maximum acquisition me-
The entire oscilloscope memory can only be read out in STOP
mode if the maximum sampling rate has been activated.
mory). The displayed sampling rate corresponds to the cur-
rent sampling rate divided by the amount of data skipped
while loading from the acquisition memory. If peak detec-
tion is activated, the displayed sampling rate corresponds
to the current sampling rate.
All settings apply the identical current sampling rate (sam-
pling rate used to write to the acquisition memory). In
STOP mode it is also possible to change menu items.
This does not impact the current memory depth but the
amount of displayed data will be adjusted. Peak detec-
tion is also activated in STOP mode (time base in micro-
seconds). In time bases displaying each sampling point,
all three settings behave identically (except used memory
depth and signal update rate). Table 5.1 displays advanta-
ges and disadvantages of each setting. Finally, it needs to
be mentioned that this menu replaces the adjustable me-
mory depth, a standard for other manufacturers. An adjus-
table memory depth is intended to allow users to under-
stand the relation between memory depth, time base and
sampling rate and to evaluate advantages and disadvanta-
ges. With this option, the oscilloscope always captures si-
gnals with the maximum sampling rate. This allows users
in STOP mode to zoom in retrospectively, even at the ma-
ximum repeat rate. It is also possible to zoom out at the
maximum repeat rate if the STOP mode was run at fast
Tab. 5.1: Advantages and disadvantages of each setting
Fig.5.3: AM modulated signal with maximum sampling rate
Fig. 5.4: AM modulated signal with automatic setting
Setting Advantages Disadvantages Application
Max. Waveform Rate ı Many captures in one image
ı Rare events can be detected more
quickly in connection with per-
sistence
ı Quick response to Operation or
change in signal
ı Low noise band
ı High aliasing risk
ı Low accuracy of details
ı Low accuracy of measurements
due to reduced amount of data
ı Search for rare events
ı Displaying modulated signals
Maximum Sampling Rate ı Maximum accuracy of details
ı Lowest aliasing risk
ı High accuracy of measurements
ı Slow response to operation or
change in signal
ı Low signal update rate
ı Higher visibility of noise
ı For signals with high frequency
parts
ı Assessment of small signal
details
Automatic: ı Average signal update rate
ı Reasonably smooth operation
ı Good accuracy of measurements
ı Low noise band
ı Possible aliasing ı Default application