Function Blocks 
4ADD Function Block 
12    HC900 Hybrid Control Designer Function Block Reference Guide  Revision 11 
  2/07 
4ADD Function Block 
Description 
The 4ADD label stands for Addition Mathematical Operation (4 Inputs). 
 
 
 
This block is part of the Math category. 
Function 
Add FOUR inputs (X, Y1, Y2, and Y3) to get an output. 
•  OUT = X+ Y1+ Y2 + Y3 
Input 
X =First Analog Input 
Y1 = Second Analog Input 
Y2 = Third Analog Input 
Y3 = Fourth Analog Input 
 
 
ATTENTION 
All 4 inputs must be connected or unused inputs inverted. If only 3 inputs are used, the 4
th
 
value should be inverted or connected to a constant value of 1.0. 
 
Output 
OUT = Sum of the analog values 
4ADD example 
HFigure 3 shows a Function Block diagram using a 4ADD function block to find the total Flow rate as the 
sum of Flow 1, Flow 2, Flow 3, and Flow 4. 
 
 
 
Figure 3  4ADD function block example