Previously, an article mentioned "Why oscilloscope manufacturers never mention the refresh rate", tells the market status of the oscilloscope manufacturers on the refresh rate parameters. Many oscilloscope users are concerned about the oscilloscope's refresh rate index. Recently, when our FAE communicated with customers, many customers are interested in the ZDS2022 oscilloscope with a high refresh rate of 330,000 frames per second. What is the high refresh rate? What did you do? The waveform refresh rate, also called the waveform capture rate, refers to the number of waveform refreshes per second, expressed as the number of waveforms per second (wfms/s). In fact, the process by which an oscilloscope displays a signal waveform from the acquisition of a signal to the screen is composed of several capture cycles. A capture cycle includes sampling time and dead time. The analog signal is converted into a digital signal by ADC sampling and stored simultaneously. The time of the entire sample storage process is called the sampling time. The oscilloscope must perform processing such as measurement and display on the stored data to start the next sampling. This time is called the dead time. During the dead time, the oscilloscope did not perform waveform acquisition. When one capture cycle is completed, it will enter the next capture cycle. The reciprocal of the capture period is the waveform refresh rate, as shown in Figure 1.1, with a waveform refresh rate = 1/(Tacq+Tdeat). Figure 1.1 Schematic diagram of oscilloscope sampling process Sampling time and dead time As shown in Figure 1.1, the waveform refresh rate is the reciprocal of Tacq (sampling time) and Tdeat (dead time), where the sampling time is determined by the sampling pane of the oscilloscope screen, and the horizontal time base is multiplied by the horizontal direction. When the horizontal time base is determined, the sampling time is fixed. The dead time is determined by the processing power of the oscilloscope. When the oscilloscope has insufficient data processing capability, the collected big data cannot be processed in time, the dead time will become longer, and the refresh rate will decrease. When the processing power of the data is strong, the dead time will be shorter and the corresponding refresh rate will be high. Therefore, dead time is an important factor affecting the refresh rate. Trigger holdoff time Increasing the trigger holdoff time is equivalent to increasing the dead time in disguise, because during the holdoff period, the trigger circuit is closed and the trigger function is suspended. Even if there is a signal waveform that meets the trigger condition, the oscilloscope will not trigger, so it will also affect the refresh rate. . However, the trigger holdoff time does not refer to the dead time. When triggering a large-cycle repeating waveform, since there are many waveform points in the waveform that satisfy the trigger condition, the trigger waveform is unstable. In order to obtain a stable trigger waveform, we can set the trigger hold-off time so that the waveform is the same every time. A point trigger triggers the stable display of the waveform. As shown in Figure 1.2, the holdoff time can be set to "200ns but a value of 600ns. Figure 1.2 Trigger holdoff time DC Capacitor For Electric Furnace DC Capacitor for Electric Furnace DC Capacitor For Electric Furnace,DCMJ DC Filter Capacitors,DCMJ Pulse Capacitors,DCMJ DC Support Capacitors YANGZHOU POSITIONING TECH CO., LTD , https://www.yzpstcc.com