Function Blocks
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Function Block Reference Guide
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2.82 XOR Function Block
Description
The
XOR
label stands for the
Exclusive OR
Boolean operation.
This block is part of the
Logic
and
Fast
Logic
categories. It looks like this graphically on the Control Builder.
OR
Fast Logic
Function
Turns a digital output signal (OUT) ON if only one of two digital input signals (X, Y) is ON. Otherwise, the
output is OFF.
•
If X = OFF and Y = ON, then:
OUT = ON.
•
If X = ON and Y = OFF, then:
OUT = ON.
•
If X = ON and Y = ON, or X = OFF and Y = OFF, then
OUT = OFF.
Input
X = First Digital Signal
Y = Second Digital Signal
Output
OUT = resultant digital signal
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 2-86 shows a Function Block Diagram using a XOR function block. In the example, if pressure
inputn or 2 are high or low, flow is disabled. If only one pressure input is ON, flow is enabled.
Figure 2-86
XOR Function Block Example