The main purpose of an oscilloscope is to measure and display voltage versus time. The oscilloscope is one of the earliest electronic test and measurement instruments. It is widely used in electrical/electronic design, test, and debugging almost anything that runs in electricity and if they’re only one piece of test equipment in a lab most of the time is the scope. The scope shows voltage versus time for periodic or repeating waveforms but modern digital oscilloscopes can also easily display and hold non periodic waveforms in addition to the basic voltage versus time display modern oscilloscopes often have many additional functions, for example, Automatic measurement i.e peak to peak voltage or frequency. The ability to look at serial buses both as bits at higher layers as well as the ability to do frequency domain analysis of signals.
Basic oscilloscope system has four primarily “systems”
-
vertical system, horizontal system, trigger system, and display system.
1.Vertical system
vertical axis shows the voltage as a function of time. It is used to scale and position waveform vertically. Most scope displays have 10 vertical divisions and to scale the waveform, use the volts per division control which controls the amplification or attenuation of the input signal. If we increase volts per division our waveform shrinks and if we decrease voltages per division our waveform increase. We use the position control to move the waveform up and down on the screen.
2.Horizontal system
Waveform display controls horizontal systems are related to the horizontal axis which corresponds to time. We use this to scale the waveform and/or change the horizontal position .similar to volts per division in the vertical system seconds per division changes the duration of each division and thus we see many cycles on the screen and the use of position control moves the waveform right or left on the screen
3.Trigger system
It is one of the most important systems. Triggering is needed for most all oscilloscope measurements essentially a trigger defines the conditions that have to be met before the scope begins an acquisition or begins takings samples. Triggering can do two different things first it can stabilize a repeating or periodic signal such as a sine wave by causing each sweep to start at a given point on the signal and the second one is to capture non-periodic single events like a single pulse burst etc. There are many types of triggers and they can be both analog and digital. Modern scopes can trigger on things like pulse, widths, glitch, etc. and most of the common trigger is called edge trigger. In edge triggering the user defines a voltage and the trigger occurs when that threshold is crossed either on the rising edge or the falling edge of a waveform.
4.Display system
In the old days of analog scopes the display system was little more than a cathode ray tube showing a glowing green trace analyzing or measuring signals often meant counting divisions on the display. Modern scopes have many display/ measurement functions such as zooming in or out of the signal and using cursors or markers to make manual measurements. large numbers of waveform parameters can be automatically measured or calculated like peak or peak to peak voltage, frequency, rise/ fall times, etc.