[New Product Suggestion] USB controlled arbitrary signal generator

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Ben321
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[New Product Suggestion] USB controlled arbitrary signal generator

Post by Ben321 »

Instead of the arbitrary waveform generator (something already built into most of the Picoscopes) that is designed to output an arbitrary waveform repetitively (even the API for controlling it lets you set the waveform's frequency), I'm suggesting something more like an ultra-fast soundcard line-out. I mean a signal generator that doesn't repeat a stored waveform, but instead after it sends each buffer to the output, requests a new buffer from the software controlling it via a callback function. This allows the software to generate a completely new set of data to send to the signal generator, each time the arbitrary signal generator asks for new data. As for sample rate and bit depth, I'm thinking of something around 10MS/Sec, and 10bits per sample (padded to a 16bit boundary, to make it easier to use in software). Software could select whether its output is DC coupled or AC coupled.

At that sample rate and bit depth, it could (in conjunction with custom software) output an NTSC composite video signal, who's output could be connected via BNC cable or RCA cable, directly to the composite video input of a TV. I'm sure it would have many other applications than this, but even within this application there's so many different test patterns that could be generated, as well as experimenting with different sync pulse widths, and seeing how it affected the TV's ability to display the picture. This could be used to test a TV's ability to display a picture with various non-standard analog video signal formats. Unlike a composite video output card for a computer that generates its own sync pulses, and only lets you customize the content of the image (letting your TV act as a computer monitor), if you were to use a USB controlled arbitrary signal generator for TV signal generating purposes, it would let you control everything about the TV signal from the software (assuming the software was written for this purpose), including sync and blanking levels and sync pulse widths and even chroma carrier phase and frequency.

And I'm sure there's even more applications than TV testing, for a USB controlled arbitrary signal generator like this, but this is one I happened to be thinking about at the moment. But really there's no limit to the types of applications that a device like this could be used for.

Gerry
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Re: [New Product Suggestion] USB controlled arbitrary signal generator

Post by Gerry »

Hi Ben,

It appears that you have 2 suggestions here.

The first is a Signal Generator with a refresh of it's contents after every completion of a generation cycle, which does indeed sound like it could be a tool with a lot of potential uses. However, as a company we're focused on Test and Measurement applications, so acquiring data to measure, and analyse is where we are spending our time. We do have tools that will generate data, but that's only secondary to what we're focussed on, i.e. their purpose is only to create an output that can then be captured and analysed (so, for instance, the Signal Generators in our Scopes are simply add-on tools for indirectly helping you to collect data).
Also, the Sig Gen is in the hardware that we design and have control over. A soundcard based Sig Gen would mean having to rely on very specific third party equipment, which has a whole host of problems, or designing our own soundcards, which takes us even further away from our focus area.

Your second suggestion is a piece of equipment focussed in the application area of video signals. Unfortunately, this is is also not an area of immediate focus for us (for instance there is some complex triggering required for specific video formats that none of our Scopes have, so far, been designed to handle).

So, as we have a limited number of already stretched resources and a limited amount of time for meeting our development goals, at this moment in time, this would not be a good thing for us to look into. Perhaps this may change in the future, and we certainly appreciate and welcome suggestions such as yours, so thanks for taking the time and trouble to put down your thoughts.

Regards,

Gerry
Gerry
Technical Specialist

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