///////////////////////////////oooooooooooooooooooooooooooooooooooooooooooooo///////////////////////////////////////////////////////////////////////////////////
public int Decode(ref BACNET_ADDRESS src, ref byte[] buf)
{
UInt16 npdu_len = 0;
BasicalProcessor.Decode_Unsigned16(ref buf, ref npdu_len, 2);
npdu_len = (UInt16)(npdu_len - 4);
int function_type = buf[1];
switch (function_type)
{
case (byte)BACNET_BVLC_FUNCTION.BVLC_ORIGINAL_BROADCAST_NPDU:
{
byte[] data = new byte[1024];
Array.Copy(buf, 4, data, 0, npdu_len);
buf = data;
break;
}
case (byte)BACNET_BVLC_FUNCTION.BVLC_DISTRIBUTE_BROADCAST_TO_NETWORK:
{
byte[] data = new byte[1024];
Array.Copy(buf, 4, data, 0, npdu_len);
buf = data;
break;
}
case (byte)BACNET_BVLC_FUNCTION.BVLC_ORIGINAL_UNICAST_NPDU:
{
byte[] data = new byte[1024];
Array.Copy(buf, 4, data, 0, npdu_len);
buf = data;
break;
}
}
return(npdu_len);
}
/**********************************************************************************************************************************************************************/
public int Decode(ref byte[] npdu, ref BACNET_ADDRESS dest, ref BACNET_ADDRESS src, ref BACNET_NPDU_DATA npdu_data)
{
int len = 0;
byte i = 0;
UInt16 src_net = 0;
UInt16 dest_net = 0;
byte address_len = 0;
byte mac_octet = 0;
npdu_data.protocol_version = npdu[0];
npdu_data.network_layer_message = ((npdu[1] & BacnetConst.BIT7) != 0) ? true : false; //是否是网络层的数据报文或者网络层协议报文
npdu_data.data_expecting_reply = ((npdu[1] & BacnetConst.BIT2) != 0) ? true : false;
npdu_data.priority = (BACNET_MESSAGE_PRIORITY)(npdu[1] & 0x03);
len = 2;
if ((npdu[1] & BacnetConst.BIT5) != 0)
{
len += BasicalProcessor.Decode_Unsigned16(ref npdu, ref dest_net, len);
address_len = npdu[len++];
dest.net = dest_net;
dest.len = address_len;
if (address_len > 0)
{
for (i = 0; i < address_len; i++)
{
mac_octet = npdu[len++];//11
dest.adr[i] = mac_octet;
}
}
}
else
{
dest.net = 0;
dest.len = 0;
for (i = 0; i < 7; i++)
{
dest.adr[i] = 0;
}
}
//源mac
if ((npdu[1] & BacnetConst.BIT3) != 0)
{
len += BasicalProcessor.Decode_Unsigned16(ref npdu, ref src_net, len); //13
address_len = npdu[len++]; //14
src.net = src_net;
src.len = address_len;
if (address_len > 0)
{
for (i = 0; i < address_len; i++)
{
mac_octet = npdu[len++]; //21
src.adr[i] = mac_octet;
}
}
}
else
{
src.net = 0;
src.len = 0;
for (i = 0; i < 7; i++)
{
src.adr[i] = 0;
}
}
//hop count
if (dest_net != 0)
{
npdu_data.hop_count = npdu[len++];
}
else
{
npdu_data.hop_count = 0;
}
//对于网络层协议无处理功能
if (npdu_data.network_layer_message)
{
npdu_data.network_message_type =
(BACNET_NETWORK_MESSAGE_TYPE)npdu[len++];
}
else
{
npdu_data.network_message_type = BACNET_NETWORK_MESSAGE_TYPE.NETWORK_MESSAGE_INVALID;
}
return(len);
}