R_TRIGPLCopen motion icon

Function BlockClosedA function block groups an algorithm and a set of private data. It has inputs and outputs. - Rising pulse detection

Inputs

CLK : BOOL Boolean signal

Outputs

Q   : BOOL TRUE when the input changes from FALSE to TRUE

Truth table

CLK CLK prev Q

0

0

0

0

1

0

1

0

1

1

1

0

Remarks

Although ]P[ and ]N[ contacts can be used in FFLD language, it is recommended to use declared instances of R_TRIG or F_TRIG function blocks in order to avoid contingencies during an Online ChangeClosedApplies to downloading PLC code changes while the applicaiton is running..

ST Language

(* MyTrigger is declared as an instance of R_TRIG function block *)
MyTrigger (CLK);
Q := MyTrigger.Q;

FBD Language

R_Trig FBD

FFLD Language

(* the input signal is the rung - the rung is the output *)
R_Trig FFLD

IL Language:

(* MyTrigger is declared as an instance of R_TRIG function block *)
Op1: CAL MyTrigger (CLK)
FFLD  MyTrigger.Q
ST  Q

See also

F_TRIG