7.2.2 CTU_INT

Function

CTU_INT is called an up counter, used to accumulate the number of input pulses (0->1 or 1->0) at the input end.

LD graphics

Parameter description

Interface variables	Declaration	Data type	Description
CU	Var_Input	BOOL	Up counter input
PV	Var_Input	INT	Preset value
R	Var_Input	BOOL	Reset input, CV cleared
Q	Var_Output	BOOL	Counter status, output bit
CV	Var_Output	INT	The value of the current count

Corresponding syntax

• Counting range: -32768~32767
• If the current value is greater than or equal to the preset value, the counter bit is turned on
• Whenever CU changes from FALSE to TRUE, CV increases by 1;
• When CV is equal to PV, Q outputs TRUE. After that, whenever CU changes from FALSE to TRUE, Q keeps outputting TRUE, and CV continues to increase to 1 until it reaches the maximum value of the integer type specified by the counter;
• At any time, as long as R is TRUE, Q outputs FALSE, and CV immediately stops counting and returns to 0

warning

Function block usage requires global declaration of an instance

Example

• LD example is shown in the following animation:

• ST example is shown in the following code:

CTU_INT_1(
    CU:=UP,
    R:=RESET,
    PV:=1,
    Q=>OUT,
    CV=>cVar
);
IF OUT THEN
    iVar:=1;
    ELSE
        iVar:=0;
END_IF;