A 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 Change.
ST Language
(* MyTrigger is declared as an instance of R_TRIG function block *)
MyTrigger (CLK);
Q := MyTrigger.Q;
FBD Language
FFLD Language
(* the input signal is the rung - the rung is the output *)
IL Language:
(* MyTrigger is declared as an instance of R_TRIG function block *)
Op1: CAL MyTrigger (CLK)
FFLD MyTrigger.Q
ST Q
See also
