Moved from LabVIEW 2009 (on NI 9104 cRIO) to LabVIEW 2012 SP1 (on NI 9082 cRIO)

[Yawei7]

Hi there,

I've been stuck on this reaally weird problem ever since I've tried moving my system from a NI 9104 cRIO developed on LabVIEW 2009 to a new NI 9082 cRIO developed on LabVIEW 2012 SP1.

Essentially, what I implemented on the old NI 9104 is reading in an error signal from a mic (through NI 9233 Module) and subtracting a Sine Wave signal (generated by a sinewave generator in FPGA vi) from the error signal. 

The sine wave is a 500 Hz tone that is played through a speaker (NI 9263 module) and is picked up by the mic that picks up the error signal. Thus the mic sees "error signal + tone" and the subtract function should perform "(error signal + tone) -  sine wave" and output a approximate 'error signal' which I am minimising.

In short, everything is the same except I'm developing in LV 2012 SP1 instead of 2009, and NI 9081 local development with Win7 instead of NI 9104. Old system works so it can't be the physical set up or physical connection problems.

But, somewhere in the FPGA vi from the sine wave generator sending a tone through a mathematical model (unchanged) to where it gets subtracted from the error signal by the subtract function- the answer of which gets sent to the host via a DMA FIFO and displayed on a graph; the old cRIO shows the expected "error signal - tone" whereas the new cRIO shows something has been ADDED onto the error tone.. I have confirmed the sine tone entering the subtract function has not been inverted in any weird way or form. 

Can anyone think of ANYTHING that might be causing this problem from the transaction from one cRIO and development platform to another? Because I am out of ideas =[ Thanks so much and if I haven't been very clear feel free to ask for clarification thank you!

Regards,

Ya-Wei.

[WishKebab]

Hi Yawei7, 

Could you post some plots of the behavior you are seeing, and the behavior you expect, from both systems?  It is a bit difficult to visualize the differences you are seeing.  One of the significant changes between the two systems is that your OS communicating with the FPGA has changed from a LabVIEW Real-time OS to a Windows non-deterministic OS.  I'm not sure if this could be causing the differences in signals, but it is certainly possible.  What was the RT controller you were using with your 9104 FPGA chassis?