This entry is written to show you how much the technologies of digital oscilloscopes have progressed. If your acquaintances say: I better use an analog (old-school) oscilloscope, invite him to read this. I guarantee – he will radically change his mind!
All technologies mentioned below, at this moment, are already available in part of entry-level oscilloscopes (price range from 299+ EUR). At the same time, the market is saturated with even more expensive oscilloscopes built based on the aged platform. Differences between the oscilloscopes of the same price range and from different manufacturers could be so huge that it is even hard to compare them. So, before buying the oscilloscope, I call you to read this entry and explore if all the mentioned features are available for your potential purchase. If even one feature is not available – I suggest not wasting money.
Basic features, which are “must-have” for even entry-level (299+ EUR) oscilloscope.
1.Memory. Name of the parameter: Memory depth. Minimal size: 1M points. Recommended size: 10+M points.
More regarding the significance of the memory depth read here and here.
In one sentence – the memory of the appropriate size is critically necessary for solving sporadic problems.
2. The equivalent refresh rate of the image. Name of the parameter: waveforms/sec. Minimal size: 10.000 waveforms/sec; optimal: 50.000+ waveforms/sec.
This technology works as following – the deadtime of the oscilloscope is reduced to a minimum; when looking at the received signal’s fragments, the oscilloscope software recognizes the difference of the exact fragment from the “usual” form and immediately outputs to the screen. Even if the oscilloscope receives thousands of signal fragments and only one of them is different, the oscilloscope’s task – put the accent to this different – “damaged” fragment.
Here, one of the videos, how this technology work:
3. Infi view, Persistance mode, etc., each manufacturer calls this feature in different ways, but the performance is identical. This feature imitates the screen “memory” with a changeable length. The user can set a short memory time (one second, two seconds, three seconds, etc.), longer (5 .. 10+ seconds), or even infinite presence. Everything that was shown on the screen will be stored in case of infinite presence memory. As if someone would draw it with a pencil on the paper. So – it is not necessary for you to carefully watch the screen of the oscilloscope worrying, that you can miss something. If there was a glitch at some point in time – the [roof will not disappear!
Example.
Video 1. Infi view is turned off; for the technician to better notice the signal (it is fed for a concise moment – approximately a hundred part of the second), the signal on the screen is saved for around 2 seconds. Excellent, it is hard to miss!
Video 2. Infi view set on 5 seconds; as you see, after the first 2 seconds, the image becomes duller (partly transparent) and is saved for 5 more seconds. All for the convenience of the user! For this oscilloscope, the time limit can be set in the range of 1 .. 30 seconds.
Video 3. Infi view set on “infinity”. After 2 seconds of a full brightness mode, the signal becomes dull and partly transparent, so it is saved for an infinite time. Here – everything, what is necessary for not to miss a glitch!
4. Zoom, mega-zoom. Different manufacturers call this feature by different names, but the aim is to relieve the work with the (large) memory of the oscilloscope.
For example – data, stored in the oscilloscope on one screen look like this:
The memory of the current oscilloscope is huge: 140M points. It means – 140 million (!) of signal values! How to see them more conveniently?
Here, how the Zoom/MegaZoom function is realized in Siglent/Agilent oscilloscopes. On the top part of the screen, the amount of memory is indicated, and the zoomed image of it is seen on the bottom part of the screen. At one time, the technician sees all the huge amount of information and details the chosen fragment. Convenient!
Of course, in addition to this method, usually, the check-up of the memory by the frames/screens (both scrolling manually or in slideshow mode) also is available.
5. Brightness gradation, typically: 256
Using different brightness of trace, the oscilloscope indicates which curve is “more popular”, which one – glitch. This feature gives an analog look to the image.
Of course, these are only several from a hundred valuable features, which are introduced in modern oscilloscopes. But – this is a basic of the basics. If I have to find a glitch (sporadic defect) in some sensor or actuator mechanism’s performance, I will connect the oscilloscope, and exactly these 5 basic features will be used as the first ones.
If the oscilloscope does not have the functionality mentioned above, do not waste money by purchasing it; after purchase, it is time to see the events, which the oscilloscope has not been recorded.
