Re: NI MIO "auxiliary" channel (i.e. on-board temperarure sensor)

On Wednesday 19 July 2006 03:30 pm, David MacMahon wrote:
>
> Bummer.  This means that AREF_OTHER is more versatile than
> CR_ALT_SOURCE.  For example, I can use comedilib's cmd program with
> AREF_OTHER to sample my PXI-6031E's ground and 5V calibration sources...

It's not more versatile, it just maps more directly on to the peculiarities 
of the e-series hardware.  This is no accident, as the e-series and 
related boards were the first boards to have calibration support added.  
Once you start trying to calibrate boards with separate adc converters for 
each channel, where each channel reads the calibration sources 
independently, you realize selecting a channel and selecting a calibration 
source are orthogonal choices in the more general case.  Also, choosing 
between reading an external or internal source has little to do with the 
meanings of the AREF_* flags.

Probably to do what you want would require generalizing the chanspec, 
something like

struct chanspec
{
	unsigned channel;
	unsigned range;
	enum Aref aref;
	unsigned flags;
	unsigned alt_source;
};

Unfortunately, we really don't have the developer resources to be doing 
that kind of unstable API development.  Maybe if we had the equivalent of 
a few FTEs, but we don't.

-- 
Frank