====== CTUD ======

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

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

CTUD

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

<code st-iec>
PROGRAM CTUD_DEMO
   VAR
     BOOL1,BOOL2,BOOL3,BOOL4,BOOL5,BOOL6: BOOL;
  INT1,INT2: INT;
     FB:CTUD;
   END_VAR
    FB(CU:=BOOL1,CD:=BOOL2,R:=BOOL3,LD:=BOOL4,PV:=INT1,QU=>BOOL5,QD=>BOOL6,CV=>INT2);
END_PROGRAM
</code>

===== Description =====

The block is an up and down counter. If both //r// and //ld// are //true//, //r// has higher priority.

===== Inputs =====

|Input|Type|Description                          |Default value|
|CU   |BOOL|Adds 1 on rising edge                |False        |
|CD   |BOOL|Subtracts 1 on rising edge           |False        |
|R    |BOOL|Reset to zero                        |False        |
|LD   |BOOL|Sets the counter to the maximum value|False        |
|PV   |INT |Maximum counter value                |0            |

===== Outputs =====

|Output|Type|Description                                      |
|QU    |BOOL|Status when the counter reaches its maximum value|
|QD    |BOOL|Status when the counter is zero                  |
|CV    |INT |Current counter value                            |

===== Application example =====

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