A function block groups an algorithm and a set of private data. It has inputs and outputs. - Set dominant bistable.
Inputs
SET1 : BOOL Condition for forcing to TRUE (highest priority command)
RESET : BOOL Condition for forcing to FALSE
Outputs
Q1 : BOOL Output to be forced
Truth table
| SET1 | RESET | Q1 prev | Q1 |
|---|---|---|---|
|
0 |
0 |
0 |
0 |
|
0 |
0 |
1 |
1 |
|
0 |
1 |
0 |
0 |
|
0 |
1 |
1 |
0 |
|
1 |
0 |
0 |
1 |
|
1 |
0 |
1 |
1 |
|
1 |
1 |
0 |
1 |
|
1 |
1 |
1 |
1 |
Remarks
The output is unchanged when both inputs are FALSE. When both inputs are TRUE, the output is forced to TRUE (set dominant).
ST Language
(* MySR is declared as an instance of SR function block *)
MySR (SET1, RESET);
Q1 := MySR.Q1;
FBD Language
FFLD Language
(* the SET1 command is the rung - the rung is the output *)
IL Language:
(* MySR is declared as an instance of SR function block *)
Op1: CAL MySR (SET1, RESET)
FFLD MySR.Q1
ST Q1
See also
