Scaling Analog Input Point Values

CygNet can scale the value of an Analog Input point. The scaling options are linear or a polynomial curve.

The equation for scaling is:

If you specify the scaling using the linear values, the PNT Editor will convert the linear values to coefficients to fit the equation.

Specifying Data Resolution

For an Analog Input point, you can use the scaling option to define the resolution of a value with or without scaling the value. For example, the remote device returns the value in hundredths and you want it to be stored in tenths, you can use the Set Decimal Places option on the Scaling page to accomplish this.

This is also useful for points for which the value is calculated, such as scripted points.

To define the resolution without scaling the data, you must ensure that there is a 1:1 relationship between the raw values and the engineering units (that is, if raw units are 0-100 then the engineering units must be 0-100). This sets the polynomial equation to X=Y, and thus the data isn’t scaled.

To Set Data Resolution without Scaling

1. Open the point editor.
2. Click on the Scaling page.
3. Click to check Enable Scaling.
4. Click to check Set Decimal Places.
5. Specify the number of decimal places you want used.
6. Set the Raw Low value to 0 and the Raw High value to 1.
7. Set the Eng Units Low value to 0 and the Eng Units High value to 1.
8. Click OK.