Flip-flop
- Block name
- ST call
- Library
- Version
- Description
- Inputs
- Outputs
- Function
- Application example

Flip-flop

Block name

BD52_FLIPFLOP

ST call

PROGRAM TESTST
 VAR
 BOOL1, BOOL2, BOOL3, BOOL4, BOOL5 :BOOL;
    FB : LIB.CORE.V1_0.BD52_FLIPFLOP;
   END_VAR
 FB(IN:=BOOL1,INF:=BOOL2,IND:=BOOL3,INFD:=BOOL4,OUT =>BOOL5); 
END_PROGRAM

Library

LIB\CORE

Version

V1.0

Description

The block controls its output value based on inputs, which read rising or faling edge, and thus set or reset the output.

Inputs

Input	Type	Description	Default value
IN	BOOL	Rising edge sets out=true	False
INF	BOOL	Falling edge sets out=true	False
IND	BOOL	Rising edge sets out=false	False
INFD	BOOL	Falling edge sets out=false	False

Outputs

Output	Type	Description
OUT	BOOL	Output value
OUTN	BOOL	Negation of the output value

Function

The block is a simple logical memory. Any rising edge at in and any falling edge at inf sets out=true. Any rising edge at ind and any falling edge at infd sets out=false. With more edges at the same time, out=false is preferred, see figure below. The output outn is negated out signal.

BD52 Flip-flop circuit – to keep it simple, inf=infd=false. Note that if more edges come at the same time, out=false is prioritized.

Application example

BD52 - Rising edge at the in input sets the output to true. May be used for aggregate / lights control using pushbuttons, or event-controlled switching.

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