The Rs Flip Flop function block prioritizes the reset input if both the inputs are "true". Rs Flip Flop has a one-bit functional block.
Rs Flip Flop function block has two inputs:
Set: Sets the device Out = "1" and is labeled "S"
Reset: Resets the device (Out = "0") labeled as "R".
The RS abbreviation stands for Set or Reset. The flip-flop is reset to its original state using the Reset input, and the output is either logic level "1" or logic level "0". It is determined by the flip-Set flop's or Reset condition. The term "flip flop" refers to the ability to be "FLIPPED" into one logic state and "FLOPPED" back into another.
The basic NOR gate and RS Flip Flop circuit are used to store the data and thus provide feedback from both of its outputs again back to its inputs.
The RSFlipFlop has three inputs Set, Reset, and Out (current output ) that relate to its current state.
|
|
Inputs with value "false" or "null" are not evaluated. The output keeps on last value.
Figure 3: RsFlipFlop - Logic Diagram
Input
Description |
|
Set |
This is a boolean point input slot. |
Reset |
This is a boolean point input slot. If both inputs are "true", it has a priority. |
Table 1:Inputs of RsFlipFlop Function
Output
Description |
|
Out |
Output = "true" or "false" based on the input and reset value. |
Table 2:Output of RsFlipFlop Function
Parameter
Description |
|
Out Save |
Master Sync Enabled : If you set it to "true" the last output will be set as output for one cycle after the controller restarts. The application can use it to return to the same state before the controller restart. Out: To enable or disable the Out feature. |
Table 3:Parameter of RsFlipFlop Function
Truth table
Set |
Reset |
Output |
false |
false |
No change or remains in previous state. |
false |
true |
false |
true |
false |
true |
true |
true |
false |
Table 4:Truth table of RsFlipFlop Function
Example
All the five conditions.
1. If Set and Reset are "true", Out is "false".
Figure 4: Set and Reset "true", Out "false".
2. Set and Reset are set to "false", Out will be retained the last state.
Figure 5: Set and Reset "false", Out last state.
3. If Set = "true"; Reset = "false", Out = "true".
Figure 6: Set "true", Reset "false" and Out = "false".
4. If Set = "false" and Reset = "true", Out = "false".
Figure 7: Set "false", Reset "true" and Out "false".
Refer to General Description for general information about IRMN4 Function Blocks.