Overlapping digital signals with analog signals in the Trending control (WFTrending3)
In order to display both digital and analog signals in the same graph view of the Trending control (WFTrending3), the user must configure the Trending control like following:
In the Change Settings window of the Trending control (at run time), the analog (ex. Frequency 1) and digital (ex. Square 1) signals must be loaded. The digital signal will not be marked as digital in the Trending Settings window, as we need to represent the signal in the same graph view as the analog one.
In order to represent the digital signal in the analog graph view in the same way the Trending control would interpret it in the digital graph view, we need to change the Interpolation method to Differential for the digital signal, while leaving the Straight Line Interpolation method for the analog signal.
As our digital signal will have values between -1 and 0 and will be represented using the Differential interpolation method, the Trending will display the following graph (red: digital, yellow: analog).
In order to make the digital signal's representation more accurate, create a new Y axis, set the Fixed Range from 0 to 1 and place the digital signal on the new Y axis.
The Trending control will display the analog signal as usual, along with the digital signal which will be placed at the bottom of the analog graph view:
The digital signal represented by the red line at the bottom of the graph