I have this plan to script an automated test setup. I want to check the behaviour of GaN power FETs.
I'll need to control the input signals that drive the FETs, the load that the FETs see, and the measurement instruments.
To make this possible, I bought a license for LabVIEW Home Edition.
I will go through the tutorials to learn LabVIEW. But I couldn't restrain myself to try things out first.
So I checked if I could control my oscilloscope and LaunchPad with it. tl;dr yes
Control Rigol DS1052E via USB and SCPI
In a distant past, I have controlled my oscilloscope with Rigol's UltraSigma program and SCPI commands. And that works.
I have some knowledge of the commands, what they do and how to use them. That's why I selected this as a first step.
You can download the NI driver for the DS1000 family. It comes with an example project*.
I launched a design that aquires the waveform on channel A and shows that on screen. It works perfectly.
In my FET test script, this info will be written to a spreadsheet.
I also tried my first own scipt. Just a small utility that releases the remote control of the oscilloscope.
This script cancels automated control and will make the buttons on the oscilloscope active again.
It's so simple that it's the right one for a Baby Steps blog.
Control a LaunchPad via USB Serial
Here I did a small check to see if I could engage in a conversation with the UART module of a Hercules LaunchPad.
The LaunchPad will be my FET signal generator. It's going to create two related PWM signals.
I'll control frequency, duty cycle and deadband via LabVIEW.
I'll need to define a handshake mechanism between LabView and controller. I think I'll write a SCPI parser/controller.
That way I have the same control language accross the setup. Choosing SCPI relieves me from having to invent something from scratch.
For today, the Baby Step day, it's enough to check if I can engage in a conversation.
I first registered the LaunchPad's serial port as a device in the Measurement & Automation Explorer.
I loaded the UART example firmware to the LaunchPad, and tested if I could connect the LabVIEW serial port monitor program.
Also success .
I still don't know much of LabVIEW. But I did get a first impression. My next steps are to do the learning trail,
sniff into all the examples that are installed, and try to fully control the scope and LaunchPad.
And to submit a good application for the programmable load.
* There's a more recent example included in the LabVIEW installation for the DS1052E. I tried that too and it works.
I don't use that in today's blog because you have to make changes to that project to make it work with your scope.
Not hard. But not a baby step.
|LabVIEW Baby Steps|
|LabVIEW Test Automation - Part 1: Hardware Setup|
|Build a Programmable Instrument|
|Create a Programmable Instrument with SCPI - Part 1: Parser Library|