NI USB-9221 Specifications

[stefano_m]

Hi, I'm evaluating the purchase of the new NI USB-9221 product and I have a doubt, while reading the manual online.

In this document I read this sentence:

The NI 9201/9221 returns uncalibrated, binary data that you

can calibrate and scale in software. Refer to your software

documentation for information about converting and calibrating

NI 9201/9221 data.

Is there someone can explain me, in few words, the meaning of this information?

 

Thank you very much for your help.

 

Stefano

 

[AlessioD]

Hi,

the comments you are referring to are trying to explain what is happening at low level when an acquisition is started.

Basically, it is true that the USB-9221 transfers raw and uncalibrated data back to the PC. On the PC side there will be the NI-DAQmx driver functions that will be taking care of scaling and calibrating the raw data coming from the hardware. This should be transparent to the user. Actually, when programming the USB device from C, LabVIEW etc (or the Logging software provided with the driver) you are going to specify the range for your signal to be acquired and the driver will return scaled data appropriately.

Regards,

AlessioD

[stefano_m]

Thank you, Alessio, now it's clear.

Best Regards

Stefano