Philip Orr

Hello! I am using LabVIEW Real-Time to analyse samples from a measurement system. The analysis is quite simplistic: FFT on a window of the samples, extract the 50 Hz signal from the FFT array, perform some work with these values (magnitude and phase both required). My problem is that by using the FFT to give me the phasor for the 50 hz signal in the input data, I am generating lots of useless data (the data for all frequencies not 50 Hz) and thus my programme is not exactly efficient... Could someone tell me a smarter, quicker, way to get just the 50 Hz component's information, and not bother having to get all the others. I heard somewhere that correlation with a 50 Hz sinusoid would yield something like this, but I'm not sure really. Any advice appreciated - Thanks.

Thanks for the replies. So, are people in agreement that the reason for no speed increase is because they both call the same function from the same library? How can I implement the speed increase and make my VI use both cores fully - do I need to make two libraries with identical functions, or is there another way? Thanks again. Philip Edit: Success! I configured the Call Lib Function nodes to 'Run in any thread' and now both cores are fully utilized. Many thanks for the advice! I'm very grateful!

Hello! I use a Macbook with 2.4Ghz Intel Core2 Duo. Having recently discovered that LabVIEW will, when possible, assign work to multiple cores, I decided to slightly alter my number-crunching simulation. The majority of processing is done by a for loop that produces an array. I split the for loop in two so that half the processing is performed by each loop, in the hope that LabVIEW would fully utilize both cores. This doesn't seem to be the case, from what I can see, although there is a good chance I am wrongly interpreting the CPU Monitor usage graphs. I have attached a cut-out of the VI showing most of the two main for loops which I hope to execute simultaneously. I've also attached an image of the CPU utilization when the VI is running. As you can see, it shows that only 50% of each core is being used. Also, the time the VI takes to execute is not drastically improved. In fact, it is very difficult to tell the difference in time, and the previous CPU utilization graph (not attached) is very similar although not as 'flat'. Can anyone explain why this is, and whether I am going about things the correct way? Many thanks for any advice! Philip