Function Blocks
Function Block Reference Guide
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2.70 TAHD Function Block
Description
The TAHD label stands for
Track and Hold
.
This block is part of the
Auxiliary
category. It looks like this
graphically on the Control Builder.
Function
Provides an output that tracks the value of the input (X), when a digital input signal (TC) is On; or when TC
is OFF, holds output at last value of X.
•
If TC = ON, then: OUT = X (TRACK)
•
If TC = OFF, then: OUT = Last value of X. (HOLD)
Input
TC = Track command signal, when turned ON.
X = Value to be tracked.
Output
OUT = track and hold value of 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.
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