determining precision of DAC in bits from Labview

[cwierzynski]

Dear Forums,

Is there a way in Labview to determine the precision in bits of a DAC? I am writing a data acquisition VI that I'd like to run in different hardware setups. In one case, the devices are PXI-4472, in which case I get 24-bit samples, and in another case it's a PXI-6289, where I get 18-bit samples.

I'm reading raw samples as I32's, but I'd like to know which bits out of the 32 are significant so that no matter what hardware I use I can extract the right bits.

I noticed that there are DAQmx properties like RawSampleWidth but these just telll me that the samples are 32 bits. Duh, I know that.

Failing that, maybe someone can tell me which bits would be significant in the case of the M series PXI-6289. Are the raw samples left-aligned (like the 4472), right aligned, or something else?

Thanks!
Casimir

[Dennis_Knutson]

You can get the number of bits of resolution with a DAQmx Channel property node. Select Analog Input>General Properties>Digitizer/ADC>Resolution Value. There is also a justification property.