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Where does shunt cal and offset nulling data get stored in NI MAX and when using a cRIO with DAQmx



I am developing an application for 8 cRIO-9056 units, for a structural health monitoring application.  We plan to use LabVIEW RT and DAQmx.  Prior to developing the software, my client used NI MAX to install a base of LabVIEW RT 19.5, and then used NI MAX to create a DAQmx task on every cRIO, and create scales and perform calibration of each strain channel.  We used the Device --> Strain Calibration feature to perform offset nulling and shunt calibration on each channel (as shown in image below). This task was repeated for all 8 cRIOs.


meas and cal.png


The issue is however, is that this calibration process was performed on one PC that we don't have access to, and we now are trying to access the cRIOs from a different PC.  So we need to understand the calibration status of the cRIOs and the channels.


This poses the following questions regarding using NI MAX / DAQmx / cRIO:

1) When you use NI MAX to create tasks/channels/scales/calibration data (ie Device Calibration such as offset nulling and shunt calibration) and then save these configurations for a cRIO, where does this data get stored on the cRIO?  I presume it gets uploaded to the cRIO and stored somewhere?  What format does it get stored on the cRIO as?  An "nce" file? How can I find/access this data?

2) If I then try to access the cRIO from a different PC, can I pull down the aforementioned configuration directly from the cRIO into NI MAX on the different PC? Or is the only way to do this by first - on the original PC - exporting to an nce file, and then on the 2nd PC - importing the nce file back into NI MAX?

3) When using the Strain Calibration feature (for strain input devices like the NI 9237), you can perform offset nulling and shunt calibration.  Does this data get stored as part of the DAQmx task inside NI MAX?  And if you export it, will it get stored in the nce file?

4) How can one export the shunt calibration and offset nulling calculated data?  Is the only way by exporting to an nce type file? You can export other calibration data, but not the shunt cal and offset nulling as far as I can see.  Any reason for this?

5) Is there a document that describes the correct process to follow for this?


Thanks in advance for any guidance/tips you can share!


I also posted this in the Multifunction DAQ forum:


Christopher Farmer

Certified LabVIEW Architect
DQMH Trusted Advisor

I'm Speaking at the GLA Summit!

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And a sixth question:

6) When I open NI MAX and look at a cRIO, I can see there are some DAQmx tasks setup on this cRIO. However I have LabVIEW 19 SP1 installed on my Windows machine, and I can't see the contents of the DAQmx task, because the cRIO's software base is currently LabVIEW 19 RT.  I want to move the cRIO to 19 SP1 (via NI MAX).  By doing this, will I lose the existing DAQmx tasks (and therefore calibration data), or will this be sustained?

Christopher Farmer

Certified LabVIEW Architect
DQMH Trusted Advisor

I'm Speaking at the GLA Summit!

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Message 2 of 2