# Callback

```{index} single: Callback
```

Message Callback

## Interface

### Event Inputs

| Name | Comment | With |
| :--- | :--- | :--- |
| REQ | Request from Socket | |

### Event Outputs

| Name | Comment | With |
| :--- | :--- | :--- |
| CNF | Confirmation from Plug | DO1 |

### Output Vars

| Name | Type | Comment |
| :--- | :--- | :--- |
| DO1 | isobus::pgn::CAN_MSG | |