ADC range utilised by 0 to 10 v input

[Nick_H]

Hi

I am using a SCXI-1520 multiplexd into a PXI-6070E with inputs configured as custom voltage with excitation (daqmx). I am expecting an input voltage range of 0 to 10V.

If I use AI.Rng.High and AI.Rng.Low to set the input range to 0 to 10V does this mean that the whole range of the 6070 a to d (12 bits) will be used to measure the 0 to 10 V signal or will just the upper half of a +/-10V a to d converter be used resulting in only 11 bits of resolution.

Any help appreciated

Regards

Nick

(not sure if this shold be under signal conditioning or multifunction daq)

[AdamB]

Hi Nick,

When you set the range to 0-10 volts. The PGIA is set to 0 - 10V so....

You will get all 12 bits of accuracy back.  However if you were to reduce the range further than you will start losing accuracy.

Thanx

AdamB

National Instruments

Message Edited by AdamB on 09-29-2005 06:26 AM

[AdamB]

Sorry people,

Got my wires crossed.

On it's own the DAQ card will work at 12 bits of accuracy with 0-10V.

However with the SCXI bolted on. it will always default to bipoler input. Therefore you will only have 11 bits of accuracy.

Sory about that.

AdamB