CTU / CTUr

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Function Block - Up counter.

Inputs

Input	Data Type	Description
CU	BOOL	Enable counting. Counter is increased on each call when CU is TRUE.
PV	DINT	Programmed maximum value.
RESET	BOOL	Reset command. Counter is reset to 0 when called with RESET to TRUE.

Input

Data Type

Range

Unit

Default

Description

BOOL

Enable counting.

Counter is increased on each call when CU is TRUE.

DINT

Programmed maximum value.

RESET

BOOL

Reset command.

Counter is reset to 0 when called with RESET to TRUE.

Outputs

Output	Data Type	Range	Unit	Description
CV	DINT			Current value of the counter.
Q	BOOL			TRUE when counter is full (i.e., when CV = PV).

Remarks

The counter is empty (CV = 0) when the application starts.
The counter does not include a pulse detection for CU input.
Use the f_trig or r_trig function blocks for counting pulses of CU input signal.
CTDr, CTUr, and CTUDr function blocks operate exactly as other counters.
- Exception: All Boolean inputs (CU, CD, RESET, LOAD) have an implicit rising edge detection included.

FBD Language Example

FFLD Language Example

In the FFLD Language, CU is the input rung.
- The output rung is the Q output.

IL Language Example

(* MyCounter is a declared instance of CTU function block. *)
Op1: CAL    MyCounter (CU, RESET, PV)
FFLD     MyCounter.Q
ST     Q
FFLD     MyCounter.CV
ST     CV

ST Language Example

(* MyCounter is a declared instance of CTU function block. *)
MyCounter (CU, RESET, PV);
Q := MyCounter.Q;
CV := MyCounter.CV;