Converting NI 9239 binary data

[Dedy]

Hi there,

on page 15 of  the operating instructions for NI 9229/9239, I found the following statement: "Analog input C series modules in the system return uncalibrated binary data when used in a CompactRIO chassis. For these modules, you can apply calibration coefficients and convert the data to engineering units in software. Refer to the software documentation for information about converting data".

Can you direct me where exactly I can find the information? I cannot find it anywhere.

Thanks,

Dedy 

[preston_johnson]

Look in the LabVIEW/examples/compactrio/shared directory for the "binary to nominal" vi.  This takes the calibration constants which you read and transfer from FPGA and then the binary values transfered from FPGA. 

You can also look at the module specific examples and find the 9239 example.  this example implements the above. 

[Dedy]

Hi,

thank you so much. I found some examples which implements this. They can be found in the Find Example under Help. I have implemented one of them. It is called Analog Input (FPGA).vi. Having specified the sampling rates to 500000 us,  I run this VI. I obtained the callibration coefficients etc. Unfortunately, the indicator of the channels do not show any change. The values shown by these indicators stay at zero. Do you have any idea what went wrong?

Dedy

[Ian Colman]

Hi Dedy,

Firstly, make sure that you are presenting valid signals on the analogue inputs that you wish to measure. Secondly, how are you running the VI? Is it being run from within a project such as the "Analog Input - cRIO.lvproj" example?

Regards,

Ian Colman
Applications Engineer
National Instruments UK & Ireland