Scale coefficients in DAQmxReadBinaryI16

[chensy]

Hi, I'm currently using USB 6210. I'm using DAQmxReadBinaryI16 to read data and save it into a file. I try to retrieve the data using scaling coefficient.
The scaling coefficient were

    scaleCoef[3]=0.000;   
    scaleCoef[2]=-0.000;
    scaleCoef[1]=0.000328723044231;
    scaleCoef[0]=0.180407148323421;

I have tried the scale coefficients in my other programs and it worked properly. Are scale coefficients return by DAQmxGetChanAttribute always the same if I use the same DAQmxReadBinaryI16 function?? Thanks for your helps.

Regards,
Chew

[samantham]

Hello,

Yes, the DAQmxGetChanAttribute will return the same scaling coefficients that you have previously specified.  There are help files in the LabWindows/CVI Help titled DAQmxGetChanAttribute and List of Channel Properties, which is a list of attributes that are available for a value check. 

Please note that the DAQmxReadBinaryI16 reads unscaled data, thus your scaling would have to happen after this function call.  Please use the DAQmxGetChanAttribute to get the DAQmx_AI_DevScalingCoeff inorder to determine what scale coefficients are needed to scale the unscaled data to a voltage.  What actual issue are you seeing?  Please describe the problem in further detail.

[chensy]

Hi,

Thanks for your reply. I just want to comfirm the values of the coefficients when I called the function DAQmxReadBinaryI16 everytime.

My problem was I need to use the coefficients without create any task. So I have to set the coefficients value to constant values.

I would like to set the coefficients as constant values since everytime i called DAQmxReadBinaryI16 will get the same values. Thanks.

Regards,

Chew