SCXI-1112 Calibration Constants - Same for NI-DAQ and NI-DAQmx?

[RickyB]

I am trying to perform an external calibration for the SCXI-1112 and have searched the NI website for related topics.  I have found 2 that are relevant (SCXI Calibration Tutorial: External Calibration with DAQmx 8.0 and Later- ) and (Performing Two-Point Calibration on an SCXI-1112).  My question relates to storing the calibration constants in the EEPROM using Traditional NI-DAQ vs. NI-DAQmx.  When using the SCXI Calibrate.vi in Traditional NI-DAQ or using the DAQmxAdjustXXXXCal + Commit to EEPROM, are the values stored in the same EEPROM area or is there a separate area for NI-DAQ and NI-DAQmx?

I would like to use Traditional NI-DAQ to calibrate the SCXI-1112 because I seem to have better control of the calibration process.  However, I would also like to be able to read my thermocouple readings with NI-DAQmx.  It is not very clear in the (SCXI Calibration Tutorial: External Calibration with DAQmx 8.0 and Later- ) how it routes the internal voltage reference on the SCXI-1112 to the rear connector using the new calibration VIs for NI-DAQmx.  This would allow me to take my voltage measurement using a DMM.  If anyone has a simplified process for calibrating the SCXI-1112, that would help too!

Regards,

RickyB

[BrowningG]

Hello RickyB,

The Calibrate SCXI VIs and functions for DAQmx are designed to make calibration of the SCXI-1112 an easy process.  For the most part, they perform the same steps as the Traditional DAQ functions.  The tutorial you mentioned is a great method for calibrating each of the channels of the SCXI-1112 individually using an external reference.  Also, with the SCXI-1112 and DAQmx you have the option to self-calibrate the device.  This self-calibration mechanism uses the onboard 5V reference for the SCXI-1112 to calibrate each channel.  As a result, the Traditional DAQ and DAQmx calibration procedures can perform the same operations up to this point. 

The VI Setup SCXI Calibration 1102.vi requires you to pick a channel to calibrate.  This function causes the output of this channel to be output on the rear connector of the SCXI module.  This is how the signal would be rerouted to the terminals on the connector block in figure 1 of the above tutorial. 

The 5V reference also has an option to be calibrated to compensate for offset drift and temperature variations on this reference.  This reference is highly stable and does not require calibration very often.  However, if you would like to calibrate this reference you will need to use the Traditional DAQ functions.  The external calibration data for the SCXI-1112 is the same whether you externally calibrate in DAQmx or Traditional DAQ so you can calibrate in Traditional DAQ and use the module in DAQmx without issue.  This was reported to R&D (#123272) for further investigation.  Post back if you have any questions.