Impulse Response with Microphone problem

[HammerTimer]

Hello all,

I am a new beginner of LabVIEW and to this forum.

I am using a modal hammer(ai0) to strike a material being investigated. The response in the material is measured by a geophone (ai1) and a microphone (connected to the laptop by usb).

Aside from the microphone which is directly connected to the laptop by USB, the instrumented hammer and the geophone is connected to the NI 9233 which is connected to the NI USB-9162 which finally connects to the laptop.

This hardware doesn't support analog triggering therefore software triggering is used.

I am using a vi example from http://www.ni.com/example/28438/en/ 

This examples is great, however, I would like to include a microphone into this vi but I am getting errors. 

Error -1931 occured at SVFA Frequency Response (1 x1) (Mag-Phase.vi:1)

I have included the microphone into the vi so that the microphone begins recording when the software triggering has been triggered. (The microphone and the geophone would start and end measurements at the same time.)

In addition, I have tried writing my measurement files but I am getting errors. How do I write the data files of each channel and the results of frequency response measurements?

Please advise.

[HammerTimer]

Does anybody have any advice regarding this?

[Justin.]

Hey HammerTimer,
I took a quick look at your VI, and noticed the error you are receiving occurs in the "SVFA Frequency Response (Mag-Phase).vi" as you correctly identified. I put some probes on the waveform wires feeding into it and noticed that there is no input to response signal Y. There is a wire feeding in, but no data on that wire. Admittedly I don't have your equipment, but I have simulated it in MAX. I appreciate I'm not sure what data you are meant to be working with either, but I would recommend double checking that you have identified the correct data you want to input to that subVI. I think you may have just miswired and actually want the data from n=0 and n=1 of your data array. I hope this helps out! 

[HammerTimer]

Hi Justin,

You were right that there was no input to the response signal Y.

Once I rewired to include an input to the response signal Y, it worked again!

Thank you very much for your help!