The Curve Fit Object not functioning in MNB / MNL controllers. Its output always reads ‘NA’ regardless of the input.

Issue

The Curve Fit Object not functioning in MNB / MNL controllers.  Its output always reads ‘NA’ regardless of the input.

Product Line

TAC I/A Series

Environment

MNB controllers (all versions), MNL controllers (all versions)

Cause

N/A

Resolution

1. Open the Curve Fit object’s properties in WorkPlace Tech

2. Change Data Point values “X1’ and “Y1” from “0” to “1”

3. Compile and download the application to the controller

4. Reopen the Curve Fit object’s properties in WorkPlace Tech

5. Change Data Point values “X1’ and “Y1” from “1” back to “0”

6. Recompile and download application to the controller again

An additional alternative is to use non-zero values for Data Points "X1" and "Y1" (e.g. 0.01).

The curve fit object should function correctly now.