CTU / CTUr

 Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Up counter.

Inputs

Input	Data Type	Range	Unit	Default	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.

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 A rising edge is the transition of a digital signal from low to high. It is also called positive edge detection included.

FBD Language Example

FFLD Language Example

• In the FFLD "Free Form Ladder Diagram" 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;

See Also

• CTD / CTDr
• CTUD / CTUDr