====== Flip-flop ======

{{:en:mervis-ide:35-help:bd52.png}}

===== Block name =====

BD52_FLIPFLOP

===== ST call =====

<code pascal>
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
</code>

===== Library =====

LIB\CORE

===== Version =====

V1.0

===== Description =====

The block controls its output value based on inputs, which read rising or falling 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.\\

{{:en:mervis-ide:35-help:bd52_1.png}}

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 =====

{{:en:mervis-ide:35-help:bd52_example.png}}

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.