Function Blocks
Function Block Reference Guide
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2.66 SUB Function Block
Description
The
SUB
label stands for the
Subtraction mathematical operation (2 Inputs)
.
This block is part of the
Math
category. It looks like this graphically on the Control Builder.
Function
Subtracts one input (X) from another (Y) to obtain an output.
•
OUT = X–Y.
Input
X
= First analog value
Y
= Second analog value
Output
OUT
= Calculated Value
Block Properties
Double click on the function block to access the function block properties dialog box.
Block Order (Read Only)
You can change the assigned execution order number by selecting “Execution Order” in the “Configure”
menu and arrange the order to suit your control strategy.
Example
Figure 2-70 shows a Function Block Diagram using a SUB function block.
Figure 2-70
SUB Function Block Example