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CTU

  • Library:
  • CTU block

Description

The CTU block implements the CTU ladder instruction. When the rung conditions are true, the block counts upwards.

Ports

Input

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Controls the execution of the block. EnableIn reflects the rung state preceding the block. If the rung state preceding the block is false, EnableIn is false, the block does not execute and the outputs are not updated.

Output

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The count up enable output contains the rung-in condition when the instruction was last executed. By default, CU follows the state of EnableIn. If the EnableIn input to the block is false, the logic implemented by the block is not executed and CU signal is set to false.

Parameters

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Specify the counter parameters in the format of tags. In Ladder Diagrams, tags (variables) are used for representing all inputs, outputs, and internal memory with attributes such as Data Type, Initial Value, and size. To change the attributes of the Operand Tag, open the Program Variables table within the Ladder Diagram Program block. The Data Type of the timer tag is of the Bus:COUNTER type with its initial value specified as a structure containing the following fields:

FieldDescriptionDefault Value
PRE

The preset value specifies the value which the accumulated value must reach before the instruction indicates it is done

0
ACC

The accumulated value specifies the number of transitions the instruction has counted.

0
CU

The count up enable contains rung-condition-in when the instruction was last executed.

1
CD

Count down enabled.

1
DN

The done bit when set indicates the counting operation is complete

0
OV

The overflow bit when set indicates the counter incremented past the upper limit of 2,147,483,647

0
UN

The underflow when set indicates the counter decremented past the lower limit of -2,147,483,648.

0

Programmatic Use

Block Parameter: PLCOperandTag
Type: character vector
Value: character vector
Default: 'T'

See Also

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Introduced in R2019a