QKnxControlField Class
The QKnxControlField class represents an 8-bit KNX control field. More...
| Header: | #include <QKnxControlField> |
| qmake: | QT += knx |
Public Types
| class | Builder |
| enum class | Acknowledge { NotRequested, Requested } |
| enum class | Broadcast { System, Domain } |
| enum class | Confirm { NoError, Error } |
| enum class | FrameFormat { Extended, Standard } |
| enum class | Priority { System, Normal, Urgent, Low } |
| enum class | Repeat { Repeat, DoNotRepeat } |
Public Functions
| QKnxControlField(const QKnxByteArray &data) | |
| QKnxControlField(quint8 data) | |
| QKnxControlField() | |
| QKnxControlField::Acknowledge | acknowledge() const |
| QKnxControlField::Broadcast | broadcast() const |
| quint8 | byte() const |
| QKnxByteArray | bytes() const |
| QKnxControlField::Confirm | confirm() const |
| QKnxControlField::FrameFormat | frameFormat() const |
| QKnxControlField::Priority | priority() const |
| QKnxControlField::Repeat | repeat() const |
| void | setAcknowledge(QKnxControlField::Acknowledge ack) |
| void | setBroadcast(QKnxControlField::Broadcast bcst) |
| void | setConfirm(QKnxControlField::Confirm conf) |
| void | setFrameFormat(QKnxControlField::FrameFormat type) |
| void | setPriority(QKnxControlField::Priority priority) |
| void | setRepeat(QKnxControlField::Repeat rep) |
| quint8 | size() const |
| bool | operator!=(const QKnxControlField &other) const |
| bool | operator==(const QKnxControlField &other) const |
Static Public Members
| QKnxControlField::Builder | builder() |
Related Non-Members
| QDebug | operator<<(QDebug debug, const QKnxControlField &field) |
Detailed Description
A KNX frame contains several fields, one of which might be the control field. The control field must specify at least the FrameFormat, the Repeat flag, and the frame Priority. In addition, it may specify how widely the frame is Broadcast, and whether acknowledgment (Acknowledge) or confirmation (Confirm) is requested for the transmission or reception of the frame.
Selecting Frame Format
The control field selects the standard or extended frame format for the data link layer and includes information for the used extended frame type. The standard format should be preferred and the extended format should only be used when the encoding capabilities of the standard format are insufficient.
Selecting Frame Priority
The priority of frames should be selected carefully to ensure fair bus access. The maximum priority that is allowed for run-time communication is normal. The system priority is reserved for system configuration and management procedures.
The urgent priority is only allowed for implementations of datapoints of functional blocks or channels for which this is specified explicitly. In a network, the frame traffic using urgent priority shall not exceed five percent of the total traffic.
See also builder() and QKnxExtendedControlField.
Member Type Documentation
enum class QKnxControlField::Acknowledge
This enum type holds whether a Layer 2 acknowledge is requested for an L_Data.req frame that is used in client-to-server communiction on the KNX data link layer. This is not valid for all media.
| Constant | Value | Description |
|---|---|---|
QKnxControlField::Acknowledge::NotRequested | 0x00 | Acknowledgment is not requested. |
QKnxControlField::Acknowledge::Requested | 0x01 | Acknowledgment is requested. |
See also QKnxLinkLayerFrame::MessageCode.
enum class QKnxControlField::Broadcast
This enum type specifies whether the frame is transmitted using system broadcast communication mode or broadcast communication mode.
| Constant | Value | Description |
|---|---|---|
QKnxControlField::Broadcast::System | 0x00 | The frame is transmitted using system broadcast communication mode. |
QKnxControlField::Broadcast::Domain | 0x01 | The frame is transmitted using broadcast communication mode. |
enum class QKnxControlField::Confirm
This enum type holds whether there is an error in the transmitted frame.
| Constant | Value | Description |
|---|---|---|
QKnxControlField::Confirm::NoError | 0x00 | No errors found. |
QKnxControlField::Confirm::Error | 0x01 | Errors found. |
enum class QKnxControlField::FrameFormat
This enum type selects the standard or extended frame format for the data link layer and includes information for the used extended frame type.
| Constant | Value | Description |
|---|---|---|
QKnxControlField::FrameFormat::Extended | 0x00 | This parameter is mapped to QKnxExtendedControlField::ExtendedFrameFormat. The extended frame format is used and the frame type is selected by the frame type parameter bit. |
QKnxControlField::FrameFormat::Standard | 0x01 | The standard frame format is used. |
enum class QKnxControlField::Priority
This enum type holds the priority used for the transmission or reception of the frame.
| Constant | Value | Description |
|---|---|---|
QKnxControlField::Priority::System | 0x00 | System priority is used. It is reserved for high priority frames, as well as system configuration and management procedures. |
QKnxControlField::Priority::Normal | 0x01 | Normal priority is used. It is the default priority for short frames. |
QKnxControlField::Priority::Urgent | 0x02 | High priority is used. It is reserved for urgent frames. |
QKnxControlField::Priority::Low | 0x03 | Low priority is used. It is mandatory for long frames, burst traffic, and so on. |
enum class QKnxControlField::Repeat
This enum type holds whether the frame transmission is repeated. If one of the addressed bus devices has returned a negative acknowledgment, the repeat flag is set to Repeat.
| Constant | Value | Description |
|---|---|---|
QKnxControlField::Repeat::Repeat | 0x00 | Frame transmission is repeated. |
QKnxControlField::Repeat::DoNotRepeat | 0x01 | Frame transmission is not repeated. |
Member Function Documentation
QKnxControlField::QKnxControlField(const QKnxByteArray &data)
Creates a new control field from the first byte of the data byte array.
Note: The byte array must contain at least one element.
QKnxControlField::QKnxControlField(quint8 data)
Creates a new control field from an 8-bit data value.
QKnxControlField::QKnxControlField()
Creates a KNX control field.
QKnxControlField::Acknowledge QKnxControlField::acknowledge() const
Returns whether a Layer 2 acknowledge is requested for an L_Data.req frame.
See also setAcknowledge() and QKnxLinkLayerFrame::MessageCode.
QKnxControlField::Broadcast QKnxControlField::broadcast() const
Returns whether the frame is transmitted using system broadcast communication mode or broadcast communication mode.
See also setBroadcast().
[static] QKnxControlField::Builder QKnxControlField::builder()
Returns a builder to create a KNX control field object.
quint8 QKnxControlField::byte() const
Returns the control field as single byte.
QKnxByteArray QKnxControlField::bytes() const
Returns the control field as a range of bytes.
QKnxControlField::Confirm QKnxControlField::confirm() const
For an L_Data.con frame, returns true if there is an error in the transmitted frame; otherwise returns false.
See also setConfirm() and QKnxLinkLayerFrame::MessageCode.
QKnxControlField::FrameFormat QKnxControlField::frameFormat() const
Returns the frame format.
See also setFrameFormat().
QKnxControlField::Priority QKnxControlField::priority() const
Returns the priority that is used for the transmission or reception of the frame.
See also setPriority().
QKnxControlField::Repeat QKnxControlField::repeat() const
Returns whether frame transmission is repeated.
See also setRepeat().
void QKnxControlField::setAcknowledge(QKnxControlField::Acknowledge ack)
Sets whether acknowledgment for an L_Data.req frame is requested to ack.
See also acknowledge() and QKnxLinkLayerFrame::MessageCode.
void QKnxControlField::setBroadcast(QKnxControlField::Broadcast bcst)
Sets the broadcast flag to bcst.
See also broadcast().
void QKnxControlField::setConfirm(QKnxControlField::Confirm conf)
Sets the confirm flag to conf.
See also confirm().
void QKnxControlField::setFrameFormat(QKnxControlField::FrameFormat type)
Sets the frame type bit of the the frame format parameter to type.
See also frameFormat().
void QKnxControlField::setPriority(QKnxControlField::Priority priority)
Sets the priority that is used for the transmission or reception of the frame.
See also priority().
void QKnxControlField::setRepeat(QKnxControlField::Repeat rep)
Sets the repetition flag to rep.
See also repeat().
quint8 QKnxControlField::size() const
Returns the number of bytes in the control field.
bool QKnxControlField::operator!=(const QKnxControlField &other) const
Returns true if this object and the given other are not equal; otherwise returns false.
bool QKnxControlField::operator==(const QKnxControlField &other) const
Returns true if this object and the given other are equal; otherwise returns false.
Related Non-Members
QDebug operator<<(QDebug debug, const QKnxControlField &field)
Writes the control field field to the debug stream.
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