Xor Function Block; Figure 2-86 Xor Function Block Example - Honeywell UMC800 Reference Manual

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.
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.
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OR

Figure 2-86 XOR Function Block Example

Function Block Reference Guide
Fast Logic
Function Blocks
243