Function Blocks
Function Block Reference Guide
3/99
208
2.71 TGFF Function Block
Description
The
TGFF
label stands for
Toggle Flip-Flop
.
This block is part of the
Logic
and
Fast Logic
categories. It
looks like this graphically on the Control Builder.
OR
Fast Logic
Function
Provides an ON state output when a digital input goes from OFF to ON and the previous state of the output
was OFF, and an OFF state output when the digital input goes from OFF to ON and the previous state of the
output was ON.
•
OUT = ON when ^TOG changes from OFF to ON and the previous state of OUT was OFF.
•
OUT = OFF when ^TOG changes from OFF to ON and the previous state of OUT was ON.
•
Reset sets output to OFF, regardless of current state.
Input
^TOG = Digital Input
RESET = Digital input ON
Input = OFF output
Output
OUT = Digital Output
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 2-75 shows a Function Block Diagram using a TGFF function block and how to tag the output.
Figure 2-75 TGFF Function Block Example