Function Block
A function block groups an algorithm and a set of private data.
It has inputs and outputs. - Rising pulse When the step gets activated, the action is activated for a single execution, and possibly once again when the step is deactivated. detection.
Inputs
|
Input |
Data Type |
Range |
Unit |
Default |
Description |
|---|---|---|---|---|---|
|
CLK |
BOOL |
|
|
|
Boolean signal. |
Outputs
|
Output |
Data Type |
Range |
Unit |
Description |
|---|---|---|---|---|
|
Q |
BOOL |
|
|
TRUE when the input changes from FALSE to TRUE. |
Remarks
- It is recommended to use declared instances of R_TRIG or F_TRIG function A function calculates a result according to the current value of its inputs.
A function has no internal data and is not linked to declared instances. blocks.
- This is to avoid contingencies during an Online Change Applies to downloading PLC code changes while the applicaiton is running..
- This is to avoid contingencies during an Online Change
Truth Table
|
CLK |
CCLK (prev) |
Q |
|---|---|---|
|
0 |
0 |
0 |
|
0 |
1 |
0 |
|
1 |
0 |
1 |
|
1 |
1 |
0 |
FBD Language Example
FFLD Language Example
- In the FFLD Language, ]P[ and ]N[ contacts can be used.
- The input signal is the rung.
- The rung is the output.
IL Language Example
(* MyTrigger is declared as an instance of R_TRIG function block *)
Op1: CAL MyTrigger (CLK)
FFLD MyTrigger.Q
ST Q
ST Language Example
(* MyTrigger is declared as an instance of R_TRIG function block *)
MyTrigger (CLK);
Q := MyTrigger.Q;
See Also
