BK Precision 2194 - Trigger Mode

Trigger 39
AC Line
The trigger signal is obtained from the AC power input of the oscilloscope. This kind of signals can be used to display
the relationship between signals (such as illuminating device) and power (power supply device). For example, it is mainly
used in related measurement of the power industry to stably trigger the waveform output from the transformer of a
transformer substation.
Note:
To select stable channel waveform as the trigger source to stabilize the display.
6.2 Trigger Mode
The oscilloscope’s trigger mode includes Auto, Normal, and Single. Trigger mode aects the way in which the oscilloscope
searches for the trigger.
After the oscilloscope starts running, the oscilloscope operates by rst lling the pre-trigger buer. It starts searching
for a trigger after the pre-trigger buer is lled and continues to ow data through this buer while it searches for the
trigger. While searching for the trigger, the oscilloscope overows the pre-trigger buer and the rst data put into the
buer is rst pushed out (First Input First Out, FIFO).
When a trigger is found, the pre- trigger buer contains the events that occurred just before the trigger. Then, the
oscilloscope lls the post- trigger buer and displays the acquisition memory.
To select the trigger mode press the key corresponding to the desired mode.
Auto
If the specied trigger conditions are not found, the triggers are forced and acquisitions are made so that signal activity
is displayed on the oscilloscope.
Auto trigger mode is appropriate when:
• Checking DDC signals or signals with unknown levels or activity.
• When trigger conditions occur often enough that forced triggers are unnecessary.
Normal
Triggers and acquisitions only occur when the specied trigger conditions are found. Otherwise, the oscilloscope holds
the original waveform and waits for the next trigger.
Normal trigger mode is appropriate when:
• Only specic events specied by the trigger settings are to be acquired.
• Triggering on an infrequent signal from a serial bus such as I2C, SPI, CAN, LIN, etc. or another signal that arrives
in bursts.
Note:
Normal trigger mode stabilizes the display by preventing the oscilloscope from auto-triggering.