oscillioscope and function generator

[kenypatel]

Hello,

How difficult is it too create a virtual oscillioscope and a function generator that outputs through ethernet or usb to some NI module (Chassis, analog, digital etc) that will send signals to a circuit? So, basically instead of having an oscillioscope or a function generator, you create a virtual one on labview and can send signals to the circuit in the real world. Is that even possible? And if it is how hard do you think the task would be? 

Thanks in advance for all the input!

[crossrulz]

Sounds like a Data Acquisition (DAQ) card to me.  Look up examples of DAQmx.  Sounds like you will want an Analog Input and an Analog Output.

[Dennis_Knutson]

The software is not that difficult and you can find examples for both. Keep in mind the hardware differences between the typical daq device and a scope. Many of the daq devices have multiple channels but they are muxed while the far fewer channels of a scope are simultaneously sampled. There are other things such as input coupling and selectable input impedance of a scope that might not be available on a daq device. You should also know that NI sells digitizers and function generators that can be used instead of traditional instruments. That is an easy route to take with performance equivalent to traditional instruments. They are not inexpensive but much cheaper usually than the bench type.

[Sam_Sharp]

If you're buying hardware - you might want to look at the VirtualBench - it's a scope, multimeter, power supply and function generator all built into one instrument. In addition to using it with a PC/iPad, you can also control it with LabVIEW.

[Henrik_Volkers]

Well, the PCI/PXI Scope and generator cards (resp. the NI-Scope and FGEN Driver)  already come with simple virtual instruments.

Called NI [FGEN,SCOPE] soft front panel

http://sine.ni.com/nips/cds/view/p/lang/de/nid/13629

It's not even possible, it's already there.

I'm shure the online help files for these virtual instruments (vi 🙂 ) can be found on the ni web.

[kenypatel]

The idea is to save cost. That is why I wanted to create a virtual oscilliscope and a function generator. That way I would have minimal cost (Yes the national instrument modules would probably be the most expensive item). The virtual function generator would send signals via digltal/analog output modules to the circuit. 

The virtual oscilloscope would recieve signals from the circuit where I could interpret the signal using some GUI on LabVIEW and have it display on a nice graph on labVIEW GUI.

So, I looked into the virtualbench and it looks great! I might consider it. So, if someone could possible help me weigh on the pros and cons of each option.

Option one being the virtual function generator and virtual oscilloscope

Option two being virtual bench.

Also I'm not exactly sure how the virtual bench works so if someone could explain that too me. Like is it just something you buy and then hook up to the circuit?

I appreciate all your feedback! It is helping me tremendously!

[crossrulz]

What is you plan for how these should be used?  If you are just trying to replace a bench oscilloscope and function generator for manual tests, just go with the Virtual Bench.  It requires no development to get it working.  If you are going for an automated system, get a PXI chassis and the PXI digitizer and function generator.

[kenypatel]

The application is for testing remotely 

Basically do everything you can currently do when testing, but be able to do it remotely

[crossrulz]

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@kenypatel wrote:

The application is for testing remotely 

Basically do everything you can currently do when testing, but be able to do it remotely

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What exactly do you mean by "remotely"?  Remote Desktop into a computer that is sitting on a bench with the equipment?  Sending commands to an RT system that is sitting inside of a controlled room?  Sending Death Rays from the International Space Station to cause bits to flip in an FPGA?

[Hooovahh]

So I happen to have a myDAQ at home and I thought I would try to use it as a scope.  Checkout this video after a 1:30 for a demo of some of this software.  The software it comes with has all the test panels for various instruments for scopes, DMM, function generator, aritrary waveform generator and several others.  The hardware also appears as a normal DAQmx device if you so choose to write your own software.

Honestly it isn't half bad.  Maybe it's because the software mirrors normal scope functionality but I was able to see my signal and understand it, when I had no other hardware that was capable.  It won't replace a desktop scope but it's what I had on hand.