|Product Performed to Expectations:||10|
|Specifications were sufficient to design with:||10|
|Demo Software was of good quality:||10|
|Product was easy to use:||10|
|Support materials were available:||10|
|The price to performance ratio was good:||10|
|TotalScore:||60 / 60|
I have the exciting privilege of road testing the Rohde and Schwarz RTB2004 digital oscilloscope. This instrument is much more than a powerful oscilloscope - it includes a very capable function generator, spectrum analysis, serial bus decoding and 16 channel logic analyzer capabilities. There are so many features, I expect this road test is going to take quite a few sessions to cover them all. As I go through my exploration of the various capabilities I will be learning how to take advantage of all the clever little features that add power and productivity to the system. Initially when focusing on a particular aspect I may not be exploiting all the related features that would make the task easier or better, but I hope to cover most of them at some point during the road test. I want to publish my exploration sessions as I do them, so they are fresh in my mind and you don't need to wait for all of them to be complete before seeing progress. Be sure to check the test plan below to see if the blog is complete or still growing.
Road Test Plan
The RTB2004 user manual has 16 chapters which will form a rough structure of topics for this road test, so there will be at least 14 exploration sessions for this aspect of the road test.
Additionally I want to blog about specific uses of this instrument in real projects where I will show it in action troubleshooting real circuits and real problems - I have lots of those. Some of them have been sitting around for a while because I just didn't have enough instrumentation to make it worthwhile trying to troubleshoot further, but with the RTB2004 that has now changed.
A few real circuirts that come to mind are:
Pulse Induction Metal Detector
BBC micro:bit I2C
I do lots of projects with piezo-electric sensors and actuators. Some of these projects push the technology in new directions and I need to look at transient response as well as frequency response and resonances. I want to use the RTB2004 to help analyze these signals, including making use of its FFT capabilities.
I will probably think of more as I dig through old project and definitely will come across excellent uses in the future while developing new designs.
Before delving into the test plan, I wanted to start with a an appetizer that showcases the cool capabilities of this scope to plot X-Y data.
If you have a scope like this, you can play the stereo audio sample I embedded to display the same image.
This instrument is over the top gorgeous. The more I use it, the more I like it and the luckier I feel that I was chosen to be a road tester. The display is simply spectacular, and I haven't even beamed it onto a big screen yet (but I will). For me this instrument represents a paradigm shift in how I troubleshoot, it combines so much powerful functionality in one instrument and streamlines the tasks so efficiently that it will get used far more than my previous instruments. Features like the deep storage memory, the high resolution A/D, the 4 channels plus logic probes, and the FFT capability allow troubleshooting problems I couldn't even tackle before.
So far I have been using the scope without reading the manual to see how intuitive the operation is for my level of competence. It probably shows in my rudimentary use of the features, but I am finding it easy to navigate and the amount of information on the screen is outstanding. It is not intuitive for me to make scope adjustments with a touch screen, but as soon as I try it, it starts to become second nature and I expect it will get harder to go back to the old knob twiddling instruments. This instrument is obviously so capable and so versatile that every electronics developer would benefit greatly from having one available.
Exploring the Function Generator
The function generator includes a wide variety of built-in waveforms with great versatility and programmability. It can take basic waveforms and add offsets, sweep functions, modulations and noise. And they can all be adjusted with digital precision.
Complex waveforms are easily programmed. The responsive touch screen and intuitive menu structure really help make this complex capability into a highly useful feature.
Saving Captured Data
Saving waveforms has been simplified down to a single button. A lot of effort has obviously been spent on making complex functionality as simple and intuitive as possible.
Remote Viewing and Control Operation
Remote viewing and control is seamlessly built-in to this instrument, adding very impressive dimensions to its applications. I have not yet explored the true power of connecting to a remote computer for automated test applications, but that is clearly something this instrument was intended to be able to handle.
I found the remote connection facilities to be surprisingly easy to set up, very responsive and spectacularly impressive. I'm now looking for an excuse to bring it to work and run it on the giant screens in our conference rooms.
Measuring Frequency, Period and Voltage of a Servo Signal
Comprehensive measurement capabilities are very easy to use, including a one-touch intelligent multi-measurement button, and the screen is so large, lots of information can be displayed without obscuring the signal.
Power Supply Noise Investigation
The next section is a bit of a detour - I noticed my videos have some hum in the audio signal, so I decided to use the scope to have a look at the problem:
Here is a picture showing the noise when the power supply is under load:
This image shows all 4 channels in use - all displaying at 20mV/div.
The other signals are mainly to show that the noise is not everywhere - it is mainly on the camera power supply. The noise is a few hundred millivolts, which can be handled by many devices that have their own regulators and many low-quality power supplies have noise in this range. In fact the camera works okay off this noisy supply, however it does cause audible noise in the microphone circuit, so I need to clean it up. It was kind of nice to get to use the scope to improve the audio in its own road test blog.
Incidentally, the image above shows that this scope can display a spectacular amount of detail - far more than most other scopes.
Fast Fourier Transform Capability
Another whole instrument capability built into this scope is the ability to perform spectrum analysis using fast Fourier transforms. It is often hard to justify buying an expensive spectrum analyzer, but this powerful capability can be extremely useful when measuring bandwidth or performance in the frequency domain.
Here is a quick look at how this scope displays the spectrum of some common waveforms:
Don suggested I show the effects of a filter on a noisy signal:
Having both a traditional oscilloscope and a spectrum analyzer in the same instrument is a natural and even more useful combination.
Serial Bus Decoding
The RTB2004 has an outstanding ability to decode serial data. It can handle I2C, SPI, UART, CAN and LIN busses and display the decoded data as binary, octal, decimal, haxadecimal or ASCII.
There are numerous methods to trigger on frames, bit patterns, byte count, etc. It and capture different word sizes, frames and packets, and it can decode both transmit and receive at the same time on different decode channels.
Its deep memory allows large amounts of data to be captured. This is a quick example of decoding SPI data sent from a BBC micro:bit to a Nokia 5110 LCD:
The ability to capture, decode and save these long GPS NMEA messages is a real time saver in collecting data for analysis. It avoids having to get hardware and software working just to get a look at the data. Trying to do this with a normal scope is very tedious and error prone, even assuming the scope has enough memory to capture a complete message. This scope makes it seamlessly easy - storing the decoded data in spreadsheet compatible files.
Acoustic Resonance Measurement
Another interesting application for this instrument is acoustic resonance measurement. I happen to need this capability in the IoT On Wheels Design Challenge. This oscilloscope is such a complete instrument, it allows exploration of my application without me having to build anything. This is a spectacular time saver and it is such a fortuitous circumstance that I have access to this amazing instrument precisely when I need it. You can see a quick video blog about it here:
I had to split the video to get it to upload...
Here I started using the FFT capability to look at resonances.
Here I explore using a surface speaker exciter to create resonant frequencies:
Pulse Induction Metal Detector Analysis
This scope is absolutely great for analyzing and tuning this pulse induction metal detector. This particular circuit has four timing circuits that need to be adjusted relative to each other and a measured signal.
I designed this circuit long before I had an RTB2004 and it was always extremely difficult to see what was going on with the timing and tune the circuit properly. With this scope everything is very clear and all relationships are easy to analyze.
Here is a video of the antenna and circuit detecting all sorts of coins from around the world:
Here is a link to the blog about the metal detector:
The more things I try to use this scope for, the more I love it.
I'm hoping to get a look at a BBC micro:bit next....