Can you specify the allowable values for vertical range and offset for the NI 5112 PCI Digitizer?

[stingrayRF]

The NI 5112 manual indicates that the vertical range can be set from +/- 25mV to +/-25V in 10% steps. Can you explain exactly what this means? (For example, could you give me a series of allowable values.)

Also, what are the allowable values for voltage offset?

The reason for my question is: I am specifying the vertical configuration using the niScope_ConfigureVertical() function. The observed raw (8 bit) sampling does not appear to change at all for small changes in voltage range and offset. I would like to know where the hardware breakpoints are, so that I can apply correct scaling from bits to voltage.

In addition, I have tried to use the niScope_CheckAt
tributeViReal64() function to "check" a value before applying it to NISCOPE_ATTR_VERTICAL_RANGE or NISCOPE_ATTR_VERTICAL_OFFSET, but it fails in the linking step in Microsoft Dev. Studio. (niScope.lib & niscope_32.lib do not seem to contain any of the CheckAttribute functions that are listed in the NI-Scope function reference.)

Thank you for your response.

[stingrayRF]

There is a nice reference at:
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/38f18d418e2433ed8625690e006bbe94?OpenDocument

which explains that allowable voltage ranges can be expressed by the equation:
next_range_value = range_value * 1.1 starting at +/- 25 mV.

When a range is specified that does not match this series, the device driver rounds UP to the next value.