How can I include an array (resulted from a multiplication of two signals from a DAQmx USB 63-56) into a TDMS file that is already open?

[alf21]

Hi.

I’m trying to calculate the power from two signals acquired from a NI USB-6365 DAQmx.  Currently, I can save both signals (voltage and current; represented by the two channels) in the TDMS format.  Nevertheless, I can’t save the resulted mathematical calculation (power; an array) in the same TDMS files were the other two signals are.  I will like to have the three signals in the same files.

Thanks.

[Julio9]

Hi alf21

I look at your VI and I make a few changes, I hope it helps you to add the third signal to your file. I use the VI's for TDMS Files, so you can add it.

Best Regards

Julio Mena

[alf21]

Hi Julio9,

Thanks for the solution.  

However, data from the third channel (double type) is not written to the TDMS file in the same rate as the other two.  For example, for every 1000 samples written from the first two channels, there is 1 sample written from the third (the one resulted from the multiplication).  

Is there any way to solve this problem?

Thanks in advanced for any advice!

[Julio9 · Accepted solution]

Hi alf21

I use a For Loop to create an arrary, here is my solutionm, I haven't tested cause a I don't have the hardware, with mi logic I think this could help you.

Regards

Julio Mena

[alf21]

Thanks Julio!  It works fine now.

Regards.