FPGA CRIO LabView - Why No Signal or Low signal?

[craige]

I'm programming LabView 8.2/RealTime 8.2 on a CRIO-9002 equipt with a 9102 chassis. I have a some 4-20mA modules, +-10v modules and last but MOST IMPORTANTLY a 9233 +-5v module.

I've programmed the FPGA and realtime and have been able to acquire and scale appropriatly for all modules except the 9233. The 9233 is hooked up to a VibraMetrics 7002 accerlometer. (http://www.vibrametrics.com/downloads/specsheets/Model%207002.pdf)

When run and an acceleration is applied I only see very low voltage on my display. Why is my 9233 is being unresponsive?

Test run at 3.5 Gvms of acceleration: (please excuse the mess)

Once again, the power spectrum should not be showing levels so low.

Thanks for your help in advance,

Craig

[Spex]

Have you checked the signal level from the accelerometer with any other measurement devices to verify that the 9233 is measuring incorrectly?  Is the voltage/current excitation for the accelerometer correct?  I am assuming you are using the binary to nominal VI for converting the binary data to the real voltage.  Make sure you are using the correct module type for the conversion. 

I am attempting to use the binary to nominal VI on the values I see on your front panel, but things are not adding up.  I used the 4th LSB Weight and Offset (656368 and -6548405)and the 4th 9233 unscaled Binary value (-7261) and converted it with the Binary to Nominal VI for the 9233 and got 0.00178252 for a nominal value while your VI appears to display 0.0067847.  I'm not sure what you are doing different than me.

The low valued power spectrum makes sense because the analog input values are low.  If we fix the analog input issue, the spectrum should take care of itself.

Without seeing your code or setup, these suggestions are obviously hypothetical.  Your screenshots show the FPGA code ok, but we have no idea how you are handling data on the host side.  In the future I would avoid embedding giant screen shots in your post, attachments are just fine.  Embedded screen shots are more effective if they only contain a small snippet of code.

Cheers,