Short summary

Name	`CTU`
→POU type	→function block
Category	IEC-block, Counter
Conform to →IEC-standard	no restrictions
Graphical interface
Available since	version 1.4.1 (for logi.CAD 3)

Functionality

The block is an up-counter (for INT values).

If there is a positive →edge at input CU, the counter is activated and increments the counter value by 1. If input R is →turned on, the counter value is reset to value 0. Enter a limiting value at input PV. If this limiting value is reached or exceeded, output Q is set to value TRUE (or an equivalent). The incrementing is stopped, if the upper limit of INT (= value 32,767) is reached. Output CV returns the current counter value of the block.

In-/outputs

	Identifier	→Data type	Description
Inputs:	`CU`	`BOOL`	increment in case of positive edge
	`R`	`BOOL`	flag for reset
	`PV`	`INT`	limiting value
Outputs:	`Q`	`BOOL`	flag showing whether limiting value is reached or not
Outputs:	`CV`	`INT`	current counter value

Input EN and output ENO are available when →calling the block. See "Execution control: EN, ENO" for information on input EN and output ENO.

Example for usage within ST-editor

PROGRAM Test
    VAR
        myCTU          : CTU;
        StartCounter   : BOOL;
        RestartCounter : BOOL;
        out            : BOOL;
        counter        : INT;
    END_VAR
 
    myCTU(CU := StartCounter, R := RestartCounter, PV := 10, Q => out, CV => counter);
    (* Instance of block 'CTU' is called: The counter is activated, when 'StartCounter' is 'TRUE'. The value for counting is reset to '0', when 'RestartCounter' is 'TRUE'. *)
    (* The limiting value for counting is '10'. *)
    (* Appropriate variables access the outputs. *)
END_PROGRAM

When creating your application within the ST-editor, enter a call of a block by typing the text as requested by the syntax or use Content Assist.