How can I read programmatically the history of a DAQmx channel calibration?

[gerh]

In the Measurement Explorer a calibrated channel of a DAQmx task contains all the data like calibration values, user name who has calibrated, a comment, some status informations and so on.

Additionally to this data a history of this shape is available:

   10.05.2012   <username removed>   calibrated

   14.04.2013   <username removed>   calibration verified

   12.06.2013   <username removed>   recalibrated

    ...

Acually I can programmatically read out all calibration and validation data attached to a selected channel of a DAQmx task, using property nodes. This works fine except for this history.

How can I get these data?

[Christoph_D]

Hi!

I am sorry but I have not found a possibility to do that programmatically. I have neither found promising properties in the DAQmx class nor have I discovered a functionality in the NI systems configuration API.

The only thing you could do is to manually export the history to a HTML file and then parse through the information programmatically.

Best regards

Christoph

[gerh]

Hi,

If it is possible, I would prefer a direct solution instead of the workaround with the generated report.

The reason is a future proof solution.

What I want to do:

I've got some DAQmx Tasks with calibration. Now I want generate a customized report which conforms to a national standard. For that, I need to extract the calibration data and to re-assamble them into a new report.

For an old calibration, it would suffice to extract the data from a HTML form. But for a recurrent use, it would be a better solution to generate the customized report directly.

Please help me to extract the history data from a DAQmx Task.

[Christoph_D]

Hi!

OK, if the recent calibration data is sufficient then we have the following possibility (see screenshot)

In case that doesnt work: What kind of hardware do you use? LabVIEW/DAQmx Version?

Best regards

Christoph

[gerh]

How explained in the initial post, I'm already this far, but I get stuck with the history data. I'm using LV 2011.

Could it be possible to extract these data from a file somewhere from the MEX without generating a report?

To remember, I'm up to create a customized report, which should contain the history data, but which also will be used in the future. So it's complicated to explain the users they have to generate each report twice - once in the MEX and once in a custom application.

[natasftw]

Do you mean MAX?  What is MEX, if not?

Can you point to the standard you're concerned with?  I'm personally unaware of any that requires the full history of calibration.  If the device fell out of calibration prior, but is currently in calibration, that's usually what people are concerned with.

[Henrik_Volkers]

---

@natasftw wrote:

Can you point to the standard you're concerned with?  I'm personally unaware of any that requires the full history of calibration.  If the device fell out of calibration prior, but is currently in calibration, that's usually what people are concerned with.

---

ISO 17025  is one. 

capter 5.6....  And I want to see the history of the testing/calibration lab standards during audits! However usually it's a collection of calibration certificates and one/some diagrams.

[gerh]

Sorry for the typo. I mean the Measurement & Automation Explorer.

The institute the work is for, is accredited after ÖVE/ÖNORM EN ISO/IEC 17025:2007. So, Henrik Volkers hits the target.

The calibration of a channel in the task contains a history, which is printed on the report. This report should be adapted to a PDF with some additional evaluations, graphs, error calculation and so on. One aspect of this modification is the history. The outline is verry strict. Until now, the report has been written by hand, but in future, it should be generated automatically without any changes in the layout. My job is to makte that possible.

Another aspect, that I will have to deal with, is a possible hardware defect (the PC). So the question should be:

   How can I read / write ...

But it is not necessary to write data into the history, it would be enough to resore it from a backup. So I hoped it is stored in a file, where I can extract the data.

[Christoph_D]

If you want to save the calibration history of the DAQmx Task, you would have to generate a protocoll every time you change the calibration or...

As I wrote before I know of no possiblity to access the history of the DAQmx task, but I included a screenshot on how to access the most recent calibration information. You could that information and save the information in a custom format or check every time if the calibration data differs from the last data and automatically save the calibration data upon change (subVI which has to be called during initialization of the specific/every task). With this you would have your own programmatically readable information.