Analog / TC Multi Point Calibration

Has anyone had the need to use or design “Multi-point Calibration Logic” for Analog I/O general. But specifically for thermocouple’s (t/c). I know all the AI modules/points have the ‘2 point calibration’ that can be accessed using PAC Manager and possibly be written to in Strategy. But has this been expanded upon in Strategy code. We are designing a system using the EPIC where in the old system (not Opto) an Analog point (t/c) could have up to a 5 point calibration.

Thanks for feedback.

To do this, I would setup a calibration float table with the five entries (create one of these tables for each input). Then create a subroutine with parameters for: the calibration table, the analog input, and a result float that computes the value (using linear interpolation or whatever method that is needed).

Edit: You would probably want 10 entries in the calibration table if the calibration points are to be configurable.

There wouldn’t happen to be any ‘sample/example’ code in any of Opto’s folders. If not, I may inquire of ‘support’, they are always a good resource.


Just searched “linear interpolation” in the search box and found this:

Thanks, I’ll look at it

The zip file contains ‘LI9_3 basic.cxf’ file, is this Chart Import file?

Yes. That is the chart you should import (going by the extension - I have not unzipped the file).

I am trying to Import this chart to see the specifics, but it was created in version R9.3b and am assuming Basic, thus the name of the cxf file ‘LI9_3 Basic’. We have various versions of PAC Control Basic, but not R9.3. Is it possible to convert this chart back to R9.0 or up to R9.6? I can open it in HexEdit and see the raw code. Is there a bit that you can change to convert the cxf file.
Thanks Dave

I don’t think the version matters, I just imported it fine into my alpha build of 10.3 that I am running.
What error are you getting?

I think I got it, I was thinking I had to match the version. I imported it into Basic vR9.6 and it imported. We’ll see if it will fit our needs