LabView: Any Thoughts?

[olsenn]

Does anyone here have any experience with using LabView? I am thinking of learning how to use to control all my bench instruments, but if it's better to just incorporate native serial port libraries into C code then I'll do that.

As an example of what I'd like to do, to start out with, is make a VI that will use my Rigol DG2041A function generator to produce a AC sweep, and use my DM3058 multimeter to capture the AV voltages over time, graph the resulting waveform, and if it's a low-pass filter for example, tell me what the -3db point is.

[caffeinatedbard]

My two cents...

If those instruments are supported by national instruments in terms of a VI library, then labview should be very easy to get you going.

If all they do is wrap their C libraries and slap a VI to call the .dll, I would stay away from labview.  You could get it working faster using VB or python or something else.

I have had to do a mixture of both and if you have to write a vi to call the function and the pass the parameters in the .dll, you might as well write it in a more standard language than the "visual" or graphic languages... 

[alm]

I would agree with the coffee-addicted bard. I believe you also use Labview drivers from C with LabWindows/CVI, though I have no experience with it. Traditional text-based programming vs. graphical programming is largely down to personal preference and applications. Math and logic tends to suck in Labview in my opinion, for example. Calling a C function is definitely more painful than in a text-based programming language. Parallel execution and easy GUI design are quite nice in Labview, however.

[nanofrog]

Unfortunately, there doesn't appear to be instrument drivers for the DG2041A (checked both Rigol and NI's site), so if you're just wanting to use LabVIEW for instrument control, you'd have to create your own files. Possible, but rather expensive for that IMO, particularly for personal use (~$2500USD for the initial base license and support purchase @ 1year IIRC, but continued support/licensing is cheaper so long as you don't let it expire). If you can use it for other purposes as well however and often, it may still be worth getting.

Rigol has their own software that comes with the unit for math functions, and it may work for instrumentation control if it's other Rigol equipment (it does use NIVISA, but it seems to be proprietary after that). I didn't really dig into this, so you'd need to check that out.

[Neilm]

The cheaper versions of Labview tend to have reduced functionality. Looking at the website, the cheapest has NO signal processing functionality.

Also, it can be a bit of a learning curve if you pick it up having been used to textual input languages - C, C++ etc. Labview code is drawn using symbols and each node can run when all the inputs are ready, not in the order they appear on the screen. I have seen quite good programmers who could not get used to this on the simple program he was writing and he eventually abandoned it.

However, if you can get used to it you can do some quite advanced things with it. For example, many years ago (win 98 SE had only just been released) I wrote a gunnery trainer simulator that drove a laser to draw multiple shots on the screen with dual screen support while compensating for the movement of the turret system it was attached to.

Yours

Neil

[RJSC]

Does anyone know some free / open-source alternatives to labview that you can tell me?

I'm not looking at the signal processing or control  libraries, I'm just after an easy way of creating Graphical User Interfaces by drag&dropping dials, displays, sliders, buttons like labview allows to that just read, display and send values to and from a serial port for example.

Doing a decent GUI is for something like an instrument GUI is a nightmare without it.

Imagine something such as a program to control the PSU Dave is designing, which has sliders to adjust voltage and current, a button tho shut the output down to 0V/0A (power-off) status light to indicate if the current limit is active and digital or analog gage to display the actual current and voltage on the output.

Is there some free software that allows to read values from a serial port and display them on analog gage I drag&dropped to a GUI window and them compile it into an executable file?

[Neilm]

You could use anything that gives you a reasonable GUI - for instance Microsoft Visual studio gives you some GUI stuff. I don't think it gives you graphs, but I think it does have sliders. Labview was originally designed to provide an instrument front end for a PC so it has controls that mimic instrument interfaces.

Neil

[bubucis]

LabView gives you an easy GUI and interface to instruments.  There is nothing better than LabView for instrumentation and test engineering, and making it easy fort the production testing.  It is pricey though as a hobby tool, for production though it is peanuts, custom software is not cheap.  Also check PyVISA for a nice python text interface to instruments.

[willd1971]

LabView needs a certain way of thinking.  If you're from a conventional scripted programming background with GUI experience you will probably find LabView very frustrating.  Sometimes I have to use it at work just because of some fancy NI acquisition hardware we need.  I always find myself spending ages trying to work out how to do what would take moments in VB.  Also, if something doesn't quite work first time or gives problems it's a lot harder to lift the lid to find out what's really going on under the cover!  Maybe I would think differently if it was my daily tool...  I use Visual Studio Express most of the time - it has everything I need for data acquisition and logging - and it's free 

William
www.labtronix.co.uk

[bubucis]

LabView does take some time to get used to it.  But I did have a nice FFT from my Rigol literally within 5 min of starting:)
 

[Antlab]

Hi.
I used Labview several years ago. Actually it was Bridgeview, the version dedicated to Industrial Automation (I think NI skipped the name successively).
The graphic language G has surely limitations for big applications, but for GUI creation with graphical controls Labview is really strong.
Unfortunately I don't know freeware/open source alternatives. But if you prefer other languages, there is the NI Measurement Studio, which seems to offer graphical controls to .NET framework (Visual Basic .NET and Visual C#).

Ciao

A.

[Time]

Labview is awesome for a professional environment - especially for R&D type stuff.  For the hobbyist I wouldnt imagine it would be so great.

[Wim_L]

Labview... Probably made because someone saw the term "spaghetti code" and wanted to make some code that really looked like that. Or maybe someone thought it would be a good idea to combine the complexities if programming with the complexities of schematic design.

I wouldn't say it's any easier just because it's a lot of point and click instead of typing code. Yes, if there's a set of standard components/instrument drivers and you just have to connect them, it's going to be faster than writing a program from scratch. If you have to write a lot of your own logic and math in it, that's a different matter. Its programming model also obscures some things that are obvious in traditional procedural languages, like where the sequence points are. In my opinion, Labview isn't used because it is a good way to write programs, but only because it has so many drivers ready to use.

For a simple programming language that can use the serial ports, you could take a look at Tcl/Tk. Excellent GUI capabilities (though not visual drag and drop, it's done through code, but pretty simple), has serial port support on Windows and Linux at least, and though it's not a speedy language it's designed to integrate easily with C code.

[bubucis]

LabView is dataflow driven so sequencing is driven by the availability of the data.  Built in math, stats and signal processing is pretty comprehensive.  Most of ops are also vectorized, same as in Matlab, etc.  It really is the best thing for the R&D lab and also test and measurement, but it is expensive:(
I also like Python for quick text based stuff, but once you need graphs and GUI LabVIEW is order of magnitude quicker for a typical lab app and more than adequate for manufacturing

SpaceX are using LabView for mission control.  Here is a sample job posting:

Description

Our rapid growth has created opportunities for additional Mission Operations Engineers focused on Mission Control software development to support the launch, orbital operations and recovery of our Falcon 1 and Falcon 9 launch vehicles and our Dragon spacecraft.

Responsibilities

    Help maintain and upgrade the PXI/LabVIEW systems that control launch pad equipment
    Help maintain and upgrade the LabVIEW-based vehicle control system used to command and monitor our Falcon 1 and Falcon 9 launch vehicles
    Assist with developing, maintaining and upgrading the LabVIEW-based Mission Operation system used to command and monitor our Dragon spacecraft
    Design, develop and support new LabVIEW-based applications and utilities as needed
    Maintenance of Mission Control Centers with the help of our IT department


With the exception of the launch pad equipment program, most of our LabVIEW programs do not interact with DAQ hardware. While hardware experience is expected, advanced LabVIEW software skills are more important.

[alm]

LabView is dataflow driven so sequencing is driven by the availability of the data.

Yes, this is nice for parallel processing. It automatically takes care of dependencies between statements.

Built in math, stats and signal processing is pretty comprehensive.

I wouldn't call the stats capability comprehensive, at least compared to other math-oriented languages like MATLAB. Last time I used it, it lacked several stats and math functions that are standard in MATLAB. Cross-correlation is one thing I remember, especially normalized cross-correlation.

It really is the best thing for the R&D lab and also test and measurement, but it is expensive:(

If your R&D lab happens to do applications that align well with Labview. I.e. no complex math or logic expressions. For math, you can get complex combinations of nodes that quickly get hard to decipher. Even something fairly simple like a Gaussian function. You can copy the original formula as comment and hope that the actual code matches the comment, or use formula/expression nodes and lose most of the advantages of G code. The same applies to logic expressions.

SpaceX are using LabView for mission control.  Here is a sample job posting:

Facebook uses PHP for I don't know how many millions of users, this doesn't make PHP the best programming language. Labview has some good and some bad points, I wouldn't call it awesome or the best.

[bubucis]

Spacecraft mission control vs Facebook 

There is Rxx and Rxy in LabVIEW.

Anyways, I am no fanboy, but just pointing out that LabView is rather effective tool if one can afford it.  It is the quickest way to prototype T&M GUIs because it does support most of the instruments and protocols out of the box.