The Sr Flip Flop function block prioritizes the set input if both the inputs are "true". Sr Flip Flop is a one-bit functional block
Sr 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 stands for Set or Reset. With the help of the Reset input, the flip-flop is reset to its original state, and the output is either logic level "1"or logic level "0". It is determined by the flip-Set flop's or Reset state. It can be "FLIPPED" into one logic state or "FLOPPED" back into another.
The basic NAND gate SR Flip Flop circuit is used to store the data and thus provides feedback from both of its outputs back to its inputs. The Sr Flip Flop has three inputs that relate to its current state: Set, Reset, and Out (current output
|
|
Inputs with value "true" or "null" are not evaluated. The output keeps on last value.
Figure 3:SrFlipFlop - Logic Diagram
Truth table
Set |
Reset |
Output |
false |
false |
No change or remains in previous state. |
false |
true |
false |
true |
false |
true |
true |
true |
true |
Table 1:Truth table of RsFlipFlop Function
Input
Description |
|
Set |
This is a Boolean point input slot. It has a priority, if both inputs are "true". |
Reset |
This is a Boolean point input slot. |
Table 2:Inputs of SrFlipFlop Function
Output
Description |
|
Out |
Output = "true" or "false" depending on the input and reset value. |
Table 3:Output of SrFlipFlop 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 4:Parameter of SrFlipFlop Function
Examples
1. Set and Reset are set to "true", Out is set to "true".
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" and Reset = "false", Out = "true".
Figure 6: Set "true"and Reset "false", Out "true".
4. If Set = "false" and Reset = "true", Out = "false".
Figure 7: Set "false"and Reset "true", Out "false".
Refer to General Description for general information about IRMN4 Function Blocks.