9802 Save to SD Card

[-_ALEX_-]

Hi all, i tried to save acquired Data from a NI 9234 to a SD card. To extend the range, the value from the module is multiplied by 100000000. To ensure that all Data are valid (unsigned int) I add 900000000.  

The "Daten anguggn.vi" is to check the result.

Unfortunately, it doesn’t look like expected. It suppose to be a Sinus (Just rename the zip to .BIN).

Can somebody help me ??

Thanks 

Message Edited by -_ALEX_- on 02-13-2009 01:42 PM

Message Edited by -_ALEX_- on 02-13-2009 01:46 PM

[EgonS]

Hi Alex,

you should check in which format the SD card function writes your data to the file (Little endian, Big Endian). Use the "Read from binary File" to select the format. Which waveform do you expect?

Egon

[-_ALEX_-]

Hi Egon, The Data are binary data in big-endian format to the open file specified by FileRefIn.With the "Read from binary File" nothing changed.The waveform should look like a sine.

Could you give me an Example ??

Thanks

[EgonS]

Hi Alex,

maybe like this.

Egon

[-_ALEX_-]

Could you see a sine look like waveform, with the CRIO-X15.zip ??

Alex

[-_ALEX_-]

In the FPGA I wired a constant to the Data Input for the NI9802, and as expected the value appeared on the "Daten anguggn.vi"Do you have any Ideas why it wont work with the Data coming from NI9234 ?? Thanks 

[EgonS]

Hi Alex,

has the constant the same Fixedpoint settigs as provided by the modul?

Egon

[-_ALEX_-]

Yes, 

It has 24 Bit Word Lengths and 4 Bit Integer word Lengths.

I am out of Ideas ...

[EgonS]

Hi Alex,

you should change the fixedpoint format of your number coming from the Mod3 output. I think you have a range overflow after multiply it with your "10 ..." constant.

Egon

[-_ALEX_-]

Hi Egon,

this could be the reason. I am not sure where to change the format. I would try it, but compieling last for 40 min ...

Thanks again !!!!