Trigger Setting - Contec DIG-100M1002-PCI User Manual

4. Functions
Probe attenuation rate
There are attenuation rates such as 1:1, 10:1, 100:1 and 1000:1 for a probe, and the passive voltage
probe of 10:1 is most commonly used.
The attenuation rate of 10:1 means that the measured voltage enters the digitizer after being attenuated
to 1/10 by the probe.
When the attenuation rate is changed by a probe, it is necessary to correct the attenuation on the
digitizer side and make the converted data 10 times.
Auto limit range
The auto limit range is a function to set whether change the input range to +/-20V automatically when
the overrange (Input signal exceeds the upper bound/lower bound of the input range of the digitizer)
occurs.
When overvoltage is input into the digitizer board, the malfunction and deterioration of the board parts
are protected by automatically changing the input range to +/-20V.

Trigger Setting

Pre-trigger/Post-trigger
The trigger signal is a signal to control the acquisition operation of the digitizer such as signal
acquisition start/stop and state switch.
There are pre-trigger and post-trigger, two kinds of trigger signals for the trigger of the digitizer.
The pre-trigger is a signal only significative when the digitizer is used in data logger mode, and when
the pre-trigger is satisfied, it starts data acquisition as data logger.
The pre-trigger occurs automatically in the digitizer inside for operational modes other than data logger
mode.
The post-trigger is merely called a trigger, and it is a particularly important function for the
oscilloscope.
In order to observe periodic signal on the screen, it is necessary to perform the acquisition that the
waveform of each record data has the same shape (Otherwise, the signal cannot be confirmed visually
with the scattered screen).
The trigger signal is used for that purpose, the usual method is to specify the level and the direction of
the voltage, and set trigger conditions for channels that input signals.
For example, set the level to +3V and the trigger to rising direction for the sine-wave signal of 1MHz
with a amplitude of 10V and an offset of 0V.
By doing so, data before and after the generation of this trigger are respectively digitized as pre-trigger
sample and post-trigger sample, and plural record waves consist of sample data with the same shape.
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DIG-100M1002-PCI