Description
You can use the "Reset/set flip-flop" instruction to reset or set the bit of a specified operand based on the signal state of the inputs R and S1. If the signal state is "1" at input R and "0" at input S1, the specified operand will be reset to "0". If the signal state is "0" at input R and "1" at input S1, the specified operand is set to "1".
Input S1 takes priority over input R. When the signal state is "1" at both inputs R and S1, the signal state of the specified operand is set to "1".
The instruction is not executed if the signal state at the two inputs R and S1 is "0". The signal state of the operand then remains unchanged.
The current signal state of the operand is transferred to output Q and can be queried there.
Parameters
The following table shows the parameters of the "Reset/set flip-flop" instruction:
|
Parameters |
Declaration |
Data type |
Memory area |
Description |
|
|---|---|---|---|---|---|
|
S7-1200 |
S7-1500 |
||||
|
R |
Input |
BOOL |
I, Q, M, D, L or constant |
I, Q, M, D, L, T, C or constant |
Enable resetting |
|
S1 |
Input |
BOOL |
I, Q, M, D, L or constant |
I, Q, M, D, L, T, C or constant |
Enable setting |
|
<Operand> |
InOut |
BOOL |
I, Q, M, D, L |
I, Q, M, D, L |
Operand that is reset or set. |
|
Q |
Output |
BOOL |
I, Q, M, D, L |
I, Q, M, D, L |
Signal state of the operand |
Example
The following example shows how the instruction works:
The operands "TagRS" and "TagOut" are reset when the following conditions are fulfilled:
-
The operand "TagIn_1" has the signal state "1".
-
The operand "TagIn_2" has the signal state "0".
The operands "TagRS" and "TagOut" are set when the following conditions are fulfilled:
-
The operand "TagIn_1" has signal state "0" and the operand "TagIn_2" has signal state "1".
-
The operands "TagIn_1" and "TagIn_2" have signal state "1".