Optimizing Dataflow in LabVIEW: In place element structures

I finally finished my project based on FBG technology!! I’m an engineer with Honors and I started an improvement of the Lightbox software for Airbus Company.

Even finished the project there is a lot of possible improvements to get a more efficient application. But is necessary to improve the less efficient part of the project first to get the best improve. LabVIEW is software developed for data flow and instrumentation control, but there is a big problem with it. Always you pass data into a VI or in a for loop the software do a copy of all data. This operation takes a lot of time and if your data flow is fast or big this can cause a slow down in the process.

I search in LabVIEW some solutions to this problem, and I’m glad to discover some structures that can solve my problem.

LabVIEW 2009 includes a structure called In place element that is included also in LabVIEW 8.5, but with a little big difference: The Data value reference. THIS IS A BIG IMPROVE. The concept of a pointer does not exist in LabVIEW an in C or other lenguajes since this, and it can be very useful.

Let’s do an example: We can do a process like the shown in the next image, there is an array of 1000 elements that is incremented 500 times. This process is repeated in a continued execution during some time.

The only change made in next image is to create two subVI for every way only for use the Profile Performance and Memory tool in a simple test. Then I execute this process some times.

The results of this example is true interesting, let’s see:

Normal VI (the vi that contains the normal for loop) consumes about 3 more time in CPU than the in place structure. But not only improves the execution time. The memory used by Normal VI is 5 times bigger!!!

Well, this results speaks very well about my next step in develop of Lightbox. I post the result here soon.

The entire example is done in an Intel i5, 4GB of ram, windows 7 and LabVIEW 2009 sp1.

Lightbox

Six years have passed since I start my degree in telecommunication engineering. But today I see the end, the last effort.

My End-of-degree project is titled: Development of an application in LabVIEW for data acquisition and treatment on MicronOptics instruments, sm125 and sm130. As you can read I developed an application in, I think, the most powerful environment for instrumentation and data work: LabVIEW.

The capabilities of MicronOptics devices are based on the fiber Bragg grating (FBG) technology. It can measure strain or temperatures or even acceleration only with one optic fiber that can be of hundreds of kilometers length. The reduced cost of this technology for some purposes and the advantages of the light to measure without noise is the cause of some companies are investing in these devices.

My work consisted in develop Lightbox for these devices: Lightbox is an application that can retrieve data by an TCP/IP connection with the sm125 &sm130 devices and process it to get adjusted information. Next it can write it into memory or you can see the information in a panel of graphs.

All developed with LabVIEW 2009. In two months of work you can have a complete software running, the time saved and the reduced cost of developing is the most attractive characteristic of LabVIEW software.

In conclusion: This project let me know LabVIEW deeper and I’m so satisfied with the result.

In the future I will post some entries to analyze the high degree of complexity of this software. 

Impossible is adjective

Impossible is adjective. Adjective is accidental, secondary, non-essential. Like an adjective is not attached to nothing, because is only a word to define the human capacity. Only oneself defines the impossible, but only someone can see this truth.
I like to start this blog with this warning today:
“Only, if you think you can, you can”