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# Button4
## `Button4` (FB)
FUNCTION\_BLOCK Button4
### Short description
> Switching element with four control inputs and four switching outputs.\
> Additionally, an overall output is available.
### Representation
### Interfaces
#### Inputs
| Name | Data type | Value range | Initial value | Function |
| ------------ | --------- | ----------- | ------------- | ----------------------------------------- |
| *xButton1* | BOOL | | | Input control button 1 |
| *xButton2* | BOOL | | | Input control button 2 |
| *xButton3* | BOOL | | | Input control button 3 |
| *xButton4* | BOOL | | | Input control button 4 |
| *xButtonOff* | BOOL | | | Input central deactivation of all outputs |
#### Outputs
| Name | Data type | Value range | Initial value | Function |
| ----- | --------- | ----------- | ------------- | ------------------ |
| *xQ1* | BOOL | | | Switching output 1 |
| *xQ2* | BOOL | | | Switching output 2 |
| *xQ3* | BOOL | | | Switching output 3 |
| *xQ4* | BOOL | | | Switching output 4 |
| *xQ* | BOOL | | | Overall output |
#### Setpoints / parameters
| Name | Data type | Value range | Initial value | Function |
| ------------------ | --------- | ----------- | ------------- | -------------------------- |
| **xButton1Visu** | BOOL | | FALSE | Function like *xButton1* |
| **xButton2Visu** | BOOL | | FALSE | Function like *xButton2* |
| **xButton3Visu** | BOOL | | FALSE | Function like *xButton3* |
| **xButton4Visu** | BOOL | | FALSE | Function like *xButton4* |
| **xButtonOffVisu** | BOOL | | FALSE | Function like *xButtonOff* |
### Function description
#### General
The five inputs for the control buttons and the five visual buttons are continuously monitored for rising edges (= button pressed).\
The switching outputs and the overall output are set depending on which input a rising edge was detected on.\
The input *xButton1* has the highest priority, the input *xButton2* the second highest priority, etc.\
If no rising edge is detected on any of the four inputs, the states of the outputs do not change.
#### Overall output *xQ*
The overall output is activated (*xQ* = TRUE) if at least one of the four switching outputs is active.\
It is not active (*xQ* = FALSE) if none of the four switching outputs is active.
| *xButton1* | *xButton2* | *xButton3* | *xButton4* | *xQ1* | *xQ2* | *xQ3* | *xQ4* | Note |
| ---------------- | ---------------- | ---------------- | ---------- | ----- | ----- | ----- | ----- | -------------------- |
| L/H | X | X | X | TRUE | FALSE | FALSE | FALSE | Actuation - Button 1 |
| FALSE, TRUE, H/L | L/H | X | X | FALSE | TRUE | FALSE | FALSE | Actuation - Button 2 |
| FALSE, TRUE, H/L | FALSE, TRUE, H/L | L/H | X | FALSE | FALSE | TRUE | FALSE | Actuation - Button 3 |
| FALSE, TRUE, H/L | FALSE, TRUE, H/L | FALSE, TRUE, H/L | L/H | FALSE | FALSE | FALSE | TRUE | Actuation - Button 4 |
Legend: X … not relevant, L/H … rising edge, H/L … falling edge
#### Central deactivation of all outputs *xButtonOff* or **xButtonOffVisu**
The outputs *xQ1* to *xQ4* are deactivated (= FALSE) if a rising edge is detected at input *xButtonOff* or at setpoint / parameter **xButtonOffVisu** (regardless of the current states at the control inputs) *xButton1* to *xButton4*).
### CODESYS
InOut:
| Scope | Name | Type | Initial |
| ----------- | ---------------- | ------ | ------- |
| Input | `xButton1` | `BOOL` | |
| Input | `xButton2` | `BOOL` | |
| Input | `xButton3` | `BOOL` | |
| Input | `xButton4` | `BOOL` | |
| Input | `xButtonOff` | `BOOL` | |
| Input Const | `xButtonOffVisu` | `BOOL` | FALSE |
| Input Const | `xButton4Visu` | `BOOL` | FALSE |
| Input Const | `xButton3Visu` | `BOOL` | FALSE |
| Input Const | `xButton2Visu` | `BOOL` | FALSE |
| Input Const | `xButton1Visu` | `BOOL` | FALSE |
| Output | `xQ1` | `BOOL` | |
| Output | `xQ2` | `BOOL` | |
| Output | `xQ3` | `BOOL` | |
| Output | `xQ4` | `BOOL` | |
| Output | `xQ` | `BOOL` | |
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