Multiple microphone sensitivities in DAQmx Create Virtual Channel

[Mystik]

Hi,

I'm using 1 PXI-4472 and 6 PXI-4462 in a PXI-1042Q chassis to acquire data from 32 microphones. The microphones are Panasonic electrets, connected to a multi-channel custom-built preamplifier, which also powers the mics. In labview I'm using DAQmx Create Virtual Channel AI microphone to set up the devices, but this VI only allows one setting / device for microphone sensitivity, irrespective of how many physical channels you define in the VI. However, the electret microphones each have a different sensitivity (which I measured manually one by one). Is there an easy way how to assign a different sensitivity to each channel on a card? Someone suggested using virtual TEDS, but unfortunately I do not know the detailed specs of each microphone (details on spec sheet have large tolerance).

[RobSims]

Hi Mystik,

Thanks for your post.

The operation of the DAQmx Create Virtual Channel VI does allow only one microphone sensitivity constant. However, it is possible to set the sensitivity of each microphone individually.

Essentially the Create Virtual Channel VI takes in an already existing task and adds in the information you give it. This means that if you feed in constants for a particular channel, and it's settings, into this VI you will add that channel (and its settings) to the task.
You can then repeat this operation over and over to add in information to the task for each channel/device.

You can achieve the above quite easily by nesting the VI in a For loop, and creating an array of constants outside of the loop. This will make your code a) smaller, b) easier to navigate, and c) more streamlined.

I have attached an example VI that demonstrates this architecturing.

I hope this helps. Let me know if I can do anything more for you.

Thanks,

[teitor]

works perfectly!. I grabbed my head trying to measure different DAQmx channels and sensitivities. thank you very much! (9234 and accelerometers)

[teitor]

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