find time shift between two signal from measurement file to find velocity

[khalid.elserfy]

i have two voltage signal with time of two laser photodiodes  placed 2 mm apart (from measurement file) , i want to find the time delay between the two signals so i can find the particle velocity between the two lasers; laser 1 ,and  laser 2

[khalid.elserfy]

i have two voltage signal with time of two laser photodiodes  placed 2 mm apart (from measurement file) , i want to find the time delay between the two signals so i can find the particle velocity between the two lasers; laser 1 ,and  laser 2

[GerdW]

Hi khalid,

the "standard" answer is: use the cross correlation of both signals…

[khalid.elserfy]

i have tried this vi as shown in the image , but the problem that i usually get the peak of Rxy at 6 sec which is the time for the whole signal is that is Correct or there is something wrong

[GerdW]

Please share your data file to get substantial help…

Which delay/displacement do you expect from your experiment?

[khalid.elserfy]

i have posted the data file and labview file , they are data for two laser places 2 mm from each other , i want to know the time to calculate the particle velocity between the two lasers

https://www.dropbox.com/s/0dy1eolqg92vibw/SV003%20pos%202%20%20%2070%20lpm.lvm?dl=0

data file is uploaded in drop dox

[GerdW]

Hi khalid,

Dropbox is prohibit from my companies network.

This is one of the reasons why you should ALWAYS attach files directly here in the forum!

(Use ZIP to compress your LVM file.)

[khalid.elserfy]

i have attached both of them again as the previous one has some modification, i tried to upload it again in zip format ,but it does not work also

[daveTW]

Hello Khalid,

then there is the possibility to create an indicator at the output of the "read from measurement file" express vi. After having startet your VI again, the signal values should appear in that indicator. Then right-click on it and select "Data Operations / Make Current Value Default". After this you can delete the express vi and turn your indicator into a control, containing the data.

Save the VI and post it again. It should be significantly bigger than before.

[khalid.elserfy]

hi Dave

i tried this method , but it does not work , i attached pic of the problem ,also i attached the labview file, they can not be connected as shown in  pic

thanks

khalid