Function Blocks
Function Block Reference Guide
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2.32 LSEL Function Block
Description
The
LSEL
label stands for
Low
Selector
.
This block is part of the
Signal Selectors
category. It looks like
this graphically on the Control Builder.
Function
Selects lower of two analog input values (X & Y) for output.
Indicates when Y is lower than X.
• If X < or = Y, then:
OUT = X; YLO = OFF.
• If X > Y, then:
OUT = Y; YLO = ON.
Input
X = Analog value.
Y = Analog value
Output
OUT = Lower analog value.
YLO = Digital signal. (ON when Y<X.)
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 2-29 shows a Function Block Diagram using an LSEL function block to monitor two analog inputs
to activate an alarm signal tag.
Figure 2-29
LSEL Function Block Example