An oscilloscope comprises four distinct basic systems: the vertical system, the horizontal system, the trigger system, and the display system. Understanding the meaning of each system will help you use the oscilloscope more effectively to complete specific measurement tasks.
The following is a brief description of the basic system and adjustment controls of analog and digital oscilloscopes. Some controls differ between analog and digital oscilloscopes.
The front panel of an oscilloscope is divided into three main areas, labeled the vertical area, horizontal area, and trigger area. Depending on the mode and type (analog or digital), your oscilloscope may have additional areas. Referring to Figure 22, the following configuration needs to be adjusted to receive input signals when using an oscilloscope:
Signal attenuation and amplification: By controlling the volts per division, the signal amplitude can be adjusted to the desired measurement range. Time base: By controlling the second division, the amount of time represented by each horizontal scale on the display can be determined. Oscilloscope trigger: Using the trigger level, a repetitive signal can be stabilized, or a single event can be triggered.
Vertical systems and control
The vertical position and scale of the waveform are controlled by the vertical control section. The vertical control also allows setting the coupling mode and other signal conditions. General vertical control includes:
Termination device: 1M ohm/50 ohm; Coupling method: DC/AC/GND; Position; Offset; Transpose on/off; Scale; Variable; Programming; Bandwidth limit: 20MHz/250MHz/Full bandwidth;
Yongping System and Control
The oscilloscope's horizontal control system is more directly related to the input signal; sampling rate and record length need to be set here. Horizontal control is used to represent the horizontal position and scale of the waveform. Common horizontal controls include:
Main time base; Delayed time base: XY mode; Scale: Waveform trace differentiation; Record length; Resolution; Sampling rate; Trigger position; Scaling;
Triggering system and control
The oscilloscope's trigger function can synchronously scan horizontally at the correct point of the signal, which is very important for clearly representing signal characteristics. Trigger control can stabilize repetitive waveforms and acquire single-pulse waveforms.
A trigger enables a repetitive waveform to be displayed stably on an oscilloscope screen by continuously displaying the same portion of the input signal. Imagine if each scan started from a different position on the signal; the image on the screen would be chaotic, as shown in Figure 35.
