The QKnxNetIpTunnelingAcknowledgeProxy class provides the means to read a tunneling acknowledgment from the generic QKnxNetIpFrame class and to create a KNXnet/IP frame based on the information. More...
|qmake:||QT += knx|
|QKnxNetIpTunnelingAcknowledgeProxy(const QKnxNetIpFrame &frame)|
Tunneling means that Engineering Tool Software (ETS) sends a single KNX frame in a KNXnet/IP frame and waits until the response arrives or a time-out is reached.
A tunneling request is sent by a KNXnet/IP client to establish a data connection to the endpoint of a KNXnet/IP server for sending a KNX frame. When a KNXnet/IP server receives a tunneling request, it immediately sends a tunneling acknowledgment to the KNXnet/IP client to confirm the reception of the request and then processes the received KNX frame.
A tunneling acknowledgment frame contains the ID and status of the communication channel between a KNXnet/IP client and server, as well as the sequence number of a tunneling request frame.
The server only processes frames with the expected sequence number or one less the expected sequence number. It discards frames with other sequence numbers and does not send a tunneling acknowledgment upon receiving them.
Note: When using QKnxNetIpTunnelingAcknowledgeProxy, care must be taken to ensure that the referenced KNXnet/IP frame outlives the proxy on all code paths, lest the proxy ends up referencing deleted data.
The following code sample illustrates how to read the tunneling acknowledgment information sent by a KNXnet/IP client:
auto netIpFrame = QKnxNetIpFrame::fromBytes(...); const QKnxNetIpTunnelingAcknowledgeProxy proxy(netIpFrame); if (!proxy.isValid()) return; auto chanId = proxy.channelId(); auto seqNum = proxy.sequenceNumber(); auto tunnelStatus = proxy.status();
Member Function Documentation
QKnxNetIpTunnelingAcknowledgeProxy::QKnxNetIpTunnelingAcknowledgeProxy(const QKnxNetIpFrame &frame)
Constructs a proxy object to read the tunneling acknowledgment information carried by the specified KNXnet/IP frame frame.
[static] QKnxNetIpTunnelingAcknowledgeProxy::Builder QKnxNetIpTunnelingAcknowledgeProxy::builder()
Returns a builder object to create a KNXnet/IP tunneling acknowledgment frame.
quint8 QKnxNetIpTunnelingAcknowledgeProxy::channelId() const
Returns the ID of the communication channel between a KNXnet/IP client and server.
true if the frame contains initialized values and is in itself valid, otherwise returns
false. A valid KNXnet/IP frame consists of at least a valid header and a size in bytes corresponding to the total size of the KNXnet/IP frame header.
See also QKnxNetIpFrameHeader::totalSize().
quint8 QKnxNetIpTunnelingAcknowledgeProxy::sequenceNumber() const
Returns the sequence number of a tunneling acknowledgment frame.
Returns the status of the communication channel between a KNXnet/IP client and server.
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