Input ranges: a question

[Frank]

Still it is not clear to me input limits and input ranges.

NI-DAQmx help says that "input limits are the maximum and
minimum values you expect to measure".

USB-6008's documentation says that input range of this
card in differential is: ±20 V, ±10 V, ±5 V, ±4 V,
±2.5 V, ±2 V, ±1.25 V, ±1 V.

So I can use as input/maximum values only the above value?

This is related with PGA gains?

[StefanK]

Hi Frank,

I just stumbled about your posting from Nov. 2005. It even got a long beard

The input range is software- setable. Depending on what input limits you tell the NI-DAQmx driver it sets the input range. E.g. in DAQ Assistant you have the possibility to set the expected minimum and maximum - these setting are used to set the gain of the amplifier and therefore define the input range.
The input limits can be found in the specs manual of the specific device and tell you the maximum voltage, that can be applied without damaging your hardware. (see page 23 for the input limits of the USB-6008 http://www.ni.com/pdf/manuals/371303e.pdf)

BTW, take a look into the great Field Wiring and Noise Considerations Manual (it's free): http://zone.ni.com/devzone/conceptd.nsf/webmain/01f147e156a1be15862568650057df15

Hope this helps,

Good luck for programming,

Stefan