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

Frank Mori Hess wrote:
> On Tuesday 18 July 2006 03:01 am, David MacMahon wrote:
> 
>>It looks like AREF_OTHER can be used by the NI MIO driver (i.e.
> 
> 
> Choosing calibration sources with AREF_OTHER is just kept around for 
> compatibility with old code.  CR_ALT_SOURCE and INSN_CONFIG_ALT_SOURCE are 
> used to select alternate voltage sources for reading by the adc.

Thanks, Frank.  Using the current ni_mio_common.c as my reference, I can 
see how to use this to include one calibration source in a cmd's 
chanlist by preconfiguring with INSN_CONFIG_ALT_SOURCE and then 
including one channel in the that has the CR_ALT_SOURCE flag.  I don't 
know whether this is a limitation of just the NI drivers, my 
understanding of how to use this, or the design, but I can't see how to 
include two different CR_ALT_SOURCE channels in a cmd's chanlist.

Furthermore, at least on the E series NI MIO boards, the on-board 
temperature monitor lives in a different "channel space" ("auxiliary" is 
the word that NI uses) from the calibration sources.  There appears to 
be no way to get the NI driver to select the temperature monitor as an 
input using CR_ALT_SOURCE/INSN_CONFIG_ALT_SOURCE.

Ideally, I'd like to include the ground and 5V calibration sources and 
the temperature monitor in my scans (along with my analog inputs).  How 
can I do this with CR_ALT_SOURCE and INSN_CONFIG_ALT_SOURCE?  What I'd 
really like is an AREF_CAL and AREF_AUX option, but that's probably not 
generic enough for general consumption. :-(

Thanks for any thoughts,
Dave

Received on 2006-07-19Z04:35:10