An engineering friend asked me when Syscomp would have an instrument with a built-in screen, the self-contained scope. Well, never say never, but as it is, we like the having a separate instrument box – a tethered scope – using a laptop (or desktop) for the display. Why? Two reasons: display resolution and operating convenience.
For example, the display of a handheld scope with built in screen might be 320×240 pixels. A typical laptop computer (eg, Toshiba Satellite L500D) has a screen resolution of 1366×768 pixels. A desktop display might be 1920×1080 or higher. Detail – such as the complexity in our network analyser display shown below – is much clearer on the laptop and desktop displays, and the screens can contain much more readout information without being cluttered.
The display is much more versatile – you can separate and hide various components of the display, and for classroom use, you can output the display to a projector.
How about operating convenience? The mechanical controls of a vintage oscilloscope were very convenient to operate. Need to change the timebase? Twist the knob. Change the trigger setting? Press on a button.
But those mechanical controls are really expensive, really big, and a major source of unreliable operation. So replacing them by a software equivalent is very attractive.
How do you provide these controls on a self-contained handheld scope? Typically, with a few pushbutton cursor controls and a heirarchy of menus. This is fine for occasional operation, but it becomes really tedious if you need to switch back and forth between setting the amplitude sensitivity, changing the trigger settings and the adjusting the timebase, for example.
On the larger screen of a tethered scope, you can operate the controls with a mouse or trackpad. Point and click, or point and drag. It’s as convenient as using mechanical controls.
Incidentally, should you be inclined to tinker with the software, it’s easy to do on this tethered scope – just modify the source code with a text editor and rerun the program.
If you need to take waveform measurements while at the end of a ladder or inside a confined space, it may make sense to use a self-contained scope – especially if you don’t have to adjust the settings frequently. But for circuit development and testing work in a lab, a tethered scope – like the popular CGR-101 and CGM-101 – are our preference for the quality of the display and the operating convenience.
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