internal static bool ProcessCemi(KnxDatagram datagram, byte[] cemi)
{
try
{
// CEMI
// --------+--------+--------+--------+----------------+----------------+--------+----------------+
// Msg |Add.Info| Ctrl 1 | Ctrl 2 | Source Address | Dest. Address | Data | APDU |
// Code | Length | | | | | Length | |
// --------+--------+--------+--------+----------------+----------------+--------+----------------+
// 1 byte 1 byte 1 byte 1 byte 2 bytes 2 bytes 1 byte 2 bytes
//
// Message Code = 0x11 - a L_Data.req primitive
// COMMON EMI MESSAGE CODES FOR DATA LINK LAYER PRIMITIVES
// FROM NETWORK LAYER TO DATA LINK LAYER
// +---------------------------+--------------+-------------------------+---------------------+------------------+
// | Data Link Layer Primitive | Message Code | Data Link Layer Service | Service Description | Common EMI Frame |
// +---------------------------+--------------+-------------------------+---------------------+------------------+
// | L_Raw.req | 0x10 | | | |
// +---------------------------+--------------+-------------------------+---------------------+------------------+
// | | | | Primitive used for | Sample Common |
// | L_Data.req | 0x11 | Data Service | transmitting a data | EMI frame |
// | | | | frame | |
// +---------------------------+--------------+-------------------------+---------------------+------------------+
// | L_Poll_Data.req | 0x13 | Poll Data Service | | |
// +---------------------------+--------------+-------------------------+---------------------+------------------+
// | L_Raw.req | 0x10 | | | |
// +---------------------------+--------------+-------------------------+---------------------+------------------+
// FROM DATA LINK LAYER TO NETWORK LAYER
// +---------------------------+--------------+-------------------------+---------------------+
// | Data Link Layer Primitive | Message Code | Data Link Layer Service | Service Description |
// +---------------------------+--------------+-------------------------+---------------------+
// | L_Poll_Data.con | 0x25 | Poll Data Service | |
// +---------------------------+--------------+-------------------------+---------------------+
// | | | | Primitive used for |
// | L_Data.ind | 0x29 | Data Service | receiving a data |
// | | | | frame |
// +---------------------------+--------------+-------------------------+---------------------+
// | L_Busmon.ind | 0x2B | Bus Monitor Service | |
// +---------------------------+--------------+-------------------------+---------------------+
// | L_Raw.ind | 0x2D | | |
// +---------------------------+--------------+-------------------------+---------------------+
// | | | | Primitive used for |
// | | | | local confirmation |
// | L_Data.con | 0x2E | Data Service | that a frame was |
// | | | | sent (does not mean |
// | | | | successful receive) |
// +---------------------------+--------------+-------------------------+---------------------+
// | L_Raw.con | 0x2F | | |
// +---------------------------+--------------+-------------------------+---------------------+
// Add.Info Length = 0x00 - no additional info
// Control Field 1 = see the bit structure above
// Control Field 2 = see the bit structure above
// Source Address = 0x0000 - filled in by router/gateway with its source address which is
// part of the KNX subnet
// Dest. Address = KNX group or individual address (2 byte)
// Data Length = Number of bytes of data in the APDU excluding the TPCI/APCI bits
// APDU = Application Protocol Data Unit - the actual payload including transport
// protocol control information (TPCI), application protocol control
// information (APCI) and data passed as an argument from higher layers of
// the KNX communication stack
//
datagram.MessageCode = cemi[0];
datagram.AditionalInfoLength = cemi[1];
if (datagram.AditionalInfoLength > 0)
{
datagram.AditionalInfo = new byte[datagram.AditionalInfoLength];
for (var i = 0; i < datagram.AditionalInfoLength; i++)
{
datagram.AditionalInfo[i] = cemi[2 + i];
}
}
datagram.ControlField1 = cemi[2 + datagram.AditionalInfoLength];
datagram.ControlField2 = cemi[3 + datagram.AditionalInfoLength];
datagram.SourceAddress = GetIndividualAddress(new[] { cemi[4 + datagram.AditionalInfoLength], cemi[5 + datagram.AditionalInfoLength] });
datagram.DestinationAddress =
GetKnxDestinationAddressType(datagram.ControlField2).Equals(KnxDestinationAddressType.Individual)
? GetIndividualAddress(new[] { cemi[6 + datagram.AditionalInfoLength], cemi[7 + datagram.AditionalInfoLength] })
: GetGroupAddress(new[] { cemi[6 + datagram.AditionalInfoLength], cemi[7 + datagram.AditionalInfoLength] }, true);
datagram.DataLength = cemi[8 + datagram.AditionalInfoLength];
datagram.Apdu = new byte[datagram.DataLength + 1];
for (var i = 0; i < datagram.Apdu.Length; i++)
{
datagram.Apdu[i] = cemi[9 + i + datagram.AditionalInfoLength];
}
datagram.Data = new byte[datagram.Apdu.Length - 2];
Array.Copy(datagram.Apdu, 2, datagram.Data, 0, datagram.Apdu.Length - 2);
if (datagram.Data.Length == 0)
{
datagram.Data = new byte[1];
datagram.Data[0] = (byte)(datagram.Apdu[1] & 0x01);
}
if (datagram.MessageCode != 0x29)
{
return(false);
}
var type = datagram.Apdu[1] >> 4;
return(true);
}
catch (Exception e)
{
Logger.LogError(e, "Unkown error occured");
}
return(false);
}
public KnxDatgramEventArgs(KnxDatagram datagram)
{
Datagram = datagram;
}
