public BACnetPacket waitForPacket(int timeout, BACnetEnums.BACNET_UNCONFIRMED_SERVICE bus)
{
do
{
BACnetPacket pkt = waitForPacket(timeout);
if (pkt.messageType == BACnetPacket.MESSAGE_TYPE.APPLICATION &&
pkt.pduType == BACnetEnums.BACNET_PDU_TYPE.PDU_TYPE_UNCONFIRMED_SERVICE_REQUEST &&
pkt.unconfirmedServiceChoice == bus)
{
return(pkt);
}
} while (true);
}
private bool DecodeUnconfirmedService(byte[] apdu_buf, int apduLen)
{
// todo, this code assumes that the service is encoded in postion number one. This is not always the case. Resolve
if ((apdu_buf[0] & 0x0f) != 0)
{
_apm.MessageProtocolError("m0025 this nibble should be zero for Unconfirmed services");
return(false);
}
if (apdu_buf[1] == (byte)BACnetEnums.BACNET_UNCONFIRMED_SERVICE.SERVICE_UNCONFIRMED_WHO_IS)
{
// http://www.bacnetwiki.com/wiki/index.php?title=Who-Is
apduUnconfirmedServiceFlag = true;
unconfirmedServiceChoice = BACnetEnums.BACNET_UNCONFIRMED_SERVICE.SERVICE_UNCONFIRMED_WHO_IS;
if (apduLen != 2)
{
int offset = 2;
// means we must have a low and high range..
lowRange = BACnetEncoding.DecodeTagContextUint(apdu_buf, ref offset, 0);
highRange = BACnetEncoding.DecodeTagContextUint(apdu_buf, ref offset, 1);
}
// and for now, we will assume only workstations issue who-is messages.
this.srcDevice.type = BACnetEnums.DEVICE_TYPE.Workstation;
}
else if (apdu_buf[1] == (byte)BACnetEnums.BACNET_UNCONFIRMED_SERVICE.SERVICE_UNCONFIRMED_I_AM)
{
apduUnconfirmedServiceFlag = true;
unconfirmedServiceChoice = BACnetEnums.BACNET_UNCONFIRMED_SERVICE.SERVICE_UNCONFIRMED_I_AM;
// I-Am described right here: http://www.bacnetwiki.com/wiki/index.php?title=I-Am
// first encoded entity is the Device Identifier...
// Encoding described here: http://www.bacnetwiki.com/wiki/index.php?title=Encoding
// Decode Device Identifier
int offset = 2;
srcDevice.deviceObjectID.DecodeApplicationTag(apdu_buf, ref offset);
Console.WriteLine("This is device: " + srcDevice.deviceObjectID);
// todo, for now, we will ignore device insance xxx if received
// and we are the client (bacnet browser )
srcDevice.packet = this;
uint maxAPDULen;
offset += BACnetEncoding.BACnetDecode_uint(apdu_buf, offset, out maxAPDULen);
Console.WriteLine("Max APDU length accepted: " + maxAPDULen);
uint segmentation_supported;
offset += BACnetEncoding.BACnetDecode_uint(apdu_buf, offset, out segmentation_supported);
Console.WriteLine("Segmentation Supported: " + segmentation_supported);
srcDevice.SegmentationSupported = (BACnetEnums.BACNET_SEGMENTATION)segmentation_supported;
uint vendorId;
offset += BACnetEncoding.BACnetDecode_uint(apdu_buf, offset, out vendorId);
Console.WriteLine("VendorId: " + vendorId);
srcDevice.VendorId = vendorId;
}
return(true);
}
