FPGA output different to emulator

[Tentotheminus9]

I've written a simple vi that outputs a sine wave using the FPGA sine generator. This passes through a half-wave rectifier setup (via a SCB-68 connector block) and back into the FPGA. When I set the execution target to the FPGA emulator the vi works perfectly. A full sine wave is displayed on one wave-chart, and a half wave on other. However, when I target the FPGA device and compile and download the vi, the output turns into what appears to be random noise. Both wave-charts show nothing like a sine wave. Whats going on?

Cheers,

Rob.

[Bharathi]

From your query, I can understand that you are using the analog output function for a particular channel for producing a sinewave and getting the halfwave through analog input function. Hope I am right, it will be better if you can send the vi

thanks
bharathi

[Tentotheminus9]

Yes thats correct. Please find attached my vi. Cheers

[Tentotheminus9]

Actually i've just found the following in a help file, i'll give it a go...

Sine Generator Details
If you target an FPGA device emulator, the Sine Generator VI outputs every point of the generated sine wave, regardless of the rate at which LabVIEW calls the VI. To produce the same data while targeting an FPGA device emulator as when targeting an FPGA device, change phase increment to take into account the rate at which the FPGA VI calls the Sine Generator VI. The following equation determines the correction for using an FPGA device emulator.

phase increment (emulation) = phase increment (FPGA) * FPGA loop time (ticks)