# Error handling

Fieldbus Access automatically sets up system signals during its initialization
face. These signals are accessed for various error information in your
application.

## CAN bus error

The system signal `fieldbusAccess_CANBusError_CAN#` receives CAN-Bus info,
warning and errors from the SocetCAN driver as follows:

* WarningLimitSet
* WarningLimitReset
* ErrorPassiveSet
* ErrorPassiveReset
* BusOff
* Overrun
* StuffError
* FormError
* AckError
* CrcError
* RxBuffHighOverrun
* RxBuffLowOverrun
* BusOffReset
* FirstBusContact

## J1939

J1939 errors and CAN bus errors are available on the following signals:

* [fieldbusAccess_J1939Error_CAN#](#j1939-error)
* [fieldbusAccess_CANBusError_CAN#](#can-bus-error)

### J1939 error

With the LinX Manager plugin configured applications will have generated files
injected. These files helps with Data Engine connection and communication.
System signal `fieldbusAccess_J1939Error_CAN#` receives listed error codes from
the J1939 stack.

Following information is available for each received error message.

| Info        | Description                                                    |
|-------------|----------------------------------------------------------------|
| Bus         | CAN bus interface #                                            |
| Level       | [Error level](appendix/j1939errors.html#error-level)           |
| Code        | [Error Codes](appendix/j1939errors.html#error-codes)           |
| Identifier  | [Error identifier](appendix/j1939errors.html#error-identifier) |
| AddInfo     | Additional info if available, like PGN concerned               |
| Description | Descripton of the error in clear text                          |
| Started     | Time when error was received                                   |
| Ended       | Time when the error was cleared (if possible)                  |
| Exists      | True if error still active                                     |

#### J1939 error example

For a table showing received errors, use `fieldbusAccessErrorModel` and add
following to main.qml:

```qml
ListView {
    id: errorListView
    width: view.width - exitButton.width
    height: view.height / 1.5
    model: fieldbusAccessErrorModel
    delegate: Rectangle {
        id: listComponent
        width: view.width - exitButton.width
        height: 20
        color: "#333"
        border {
            width: 1
            color: "#777"
        }

        property color textColor: level == 'OK' ? "#fff" : "#f33"

        Row {
            spacing: 25
            topPadding: 2
            Text {
                text: Number.fromLocaleString(addInfo).toString(16).toUpperCase()
                color: listComponent.textColor
            }
            Text {
                text: level
                color: listComponent.textColor
            }
            Text {
                text: description
                color: listComponent.textColor
            }
            Text {
                text: started
                color: listComponent.textColor
            }
        }
    }
}
```

**Output:**

Info | Level | Description                                        | Received
-----|-------|----------------------------------------------------|------------------------
FEEE | Error | A registered message wasn't received in given time | 2021-03-18T13:43:09.974
FF71 | Error | A registered message wasn't received in given time | 2021-03-18T13:43:09.974
FEEE | Error | A registered message wasn't received in given time | 2021-03-18T13:43:10.524

For a description of received error codes, please see [J1939 Error
description](appendix/j1939errors)

## CANopen

Stack errors, NMT state and bus errors will be available as Data Engine signals:

* [fieldbusAccess_CANopenError_CAN#](#canopen-error)
* [fieldbusAccess_CANopenStatus_CAN#](#canopen-status)
* [fieldbusAccess_CANBusError_CAN#](#can-bus-error)

If loosing connection to Data Engine, the node will go to pre-operational. This
behaviour is configurable.

### CANopen error

With the LinX Manager plugin configured applications will have generated files
injected. These files helps with Data Engine connection and communication. The
system signal `fieldbusAccess_CANopenError_CAN#` receives CANopen stack specific
errors.

For a description of received error codes, please see [CANopen Error
description](appendix/canopenerrors)

#### CANopen error example

For a table showing received errors, use `canopenStatusModel` and add
following to main.qml:

```qml
ListView {
    id: listView
    anchors {
        left: parent.left
        right: parent.right
        top: parent.top
        margins: 10
    }
    width: view.width - exitButton.width
    height: view.height / 1.5
    model: canopenStatusModel

    delegate: Rectangle {
        id: listDelegate
        implicitWidth: listView.width - exitButton.width
        implicitHeight: 30
        color: "#000"
        border {
            width: 1
            color: "#ccc"
        }
        Row {
            anchors.fill: parent
            anchors.leftMargin: 10
            spacing: 5

            Text {
                anchors.verticalCenter: parent.verticalCenter
                color: "#fff"
                text: bus
            }
            Text {
                anchors.verticalCenter: parent.verticalCenter
                color: "#fff"
                text: type
            }
            Text {
                anchors.verticalCenter: parent.verticalCenter
                color: "#fff"
                text: message
            }
            Text {
                anchors.verticalCenter: parent.verticalCenter
                color: "#fff"
                text: received
            }
        }
    }
}
```

**Output:**

CAN-bus | Level  | Description     | Received
--------|--------|-----------------|------------------------
0       | Error  | Successful      | 2021-03-18T14:54:20.549
0       | Status | Pre-operational | 2021-03-18T14:54:20.549

### CANopen status

The system signal `fieldbusAccess_CANopenStatus_CAN#` receives stack state
specific information from the Network Management (NMT).

State           | Code (hex)
----------------|-----------
Initialisation  | 0x00
Pre-Operational | 0x04
Operational     | 0x05
Stopped         | 0x7F

#### CANopen status example

To show information about received status, add following to main.qml.

```qml
Text {
    anchors.right: parent.right
    anchors.bottom: parent.bottom
    color: "#C00"
    font.pixelSize: 32;
    text: (dataEngine.fieldbusAccess_CANopenStatus_CAN0.value === FieldbusAccessCANopenStatusModel.NodeStateInitialisation) ? "Initialisation" :
            (dataEngine.fieldbusAccess_CANopenStatus_CAN0.value === FieldbusAccessCANopenStatusModel.NodeStateStopped) ? "Stopped" :
            (dataEngine.fieldbusAccess_CANopenStatus_CAN0.value === FieldbusAccessCANopenStatusModel.NodeStateOperational) ? "Operational" :
            (dataEngine.fieldbusAccess_CANopenStatus_CAN0.value === FieldbusAccessCANopenStatusModel.NodeStatePreOperational) ? "Pre Operational" : "N/A";
}
```

**Output:**

| Description     |
| ----------------|
| Pre Operational |