Modes of Triggering in Oscilloscope - CRO
Dec 6th, 2009 by admin
Before we discussed about the different triggering modes in oscilloscope, let me remind you why we need triggering function in oscilloscope. Well, triggering is done in oscilloscope in order to display a stable waveform in the screen when there is repetitive signal running continuously in the screen.
There are different modes of triggering an oscilloscope:
1. Normal
2. Auto
3. Auto Level
4. Single Sequence
5. Video line
6. Video Field
The normal mode and the auto mode are the two commonest modes of oscilloscope triggering. In normal mode the oscilloscope sweeps only when the input signal satisfies the condition of triggering otherwise there will be not triggering and in case of analog oscilloscope there will not be any display of signal. In case of digital oscilloscope, there won’t be new display but frozen on the last acquired waveform.
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In auto mode of triggering, there will be sweep even if the input signal does not meet the requirement of the triggering. There will be less setting in the auto mode of triggering and when there is no signal, a timer in the oscilloscope triggers the sweep.
The source of the triggering signal can be any of the following signals:
1. Channel 1 (Ch1)
2. Channel 2 (Ch2)
3. Line
4. Ext
5. Add
6. Vert
The types of triggering are another important aspect of triggering a signal in oscilloscope. Edge, video, pulse and logic are some of the types of triggering but edge triggering is the most basic and common type of triggering. In edge triggering, the voltage level of the triggering signal and the condition of triggering (positive edge triggering or negative edge triggering) are important.