/// <summary>
/// Read Property.
/// </summary>
/// <param name="recipient">The recipient.</param>
/// <param name="arrayidx">The arrayidx.</param>
/// <param name="objtype">The objtype.</param>
/// <param name="objprop">The objprop.</param>
/// <param name="property">The property.</param>
/// <returns></returns>
public bool SendReadProperty(
Device recipient,
int arrayidx,
BacnetEnums.BacnetObjectType objtype,
BacnetEnums.BacnetPropertyId objprop,
Property property)
{
// Create and send an Confirmed Request
//value = "(none)";
if (recipient == null)
{
return(false);
}
if (property == null)
{
return(false);
}
//uint instance = BACnetData.Devices[deviceidx].Instance;
var sendBytes = new byte[50];
// BVLL
sendBytes[0] = Bvlc.BacnetBvlcTypeBip;
sendBytes[1] = Bvlc.BacnetBvlcFuncUnicastNpdu;
sendBytes[2] = 0x00;
sendBytes[3] = 0x00; // BVLL Length, fix later (24?)
// NPDU
sendBytes[4] = BacnetEnums.BacnetProtocolVersion;
if (recipient.SourceLength == 0)
{
sendBytes[5] = 0x04; // Control flags, no destination address
}
else
{
sendBytes[5] = 0x24; // Control flags, with broadcast or destination address
}
uint len = 6;
if (recipient.SourceLength > 0)
{
// Get the (MSTP) Network number (2001)
var temp2 = BitConverter.GetBytes(recipient.Network);
sendBytes[len++] = temp2[1];
sendBytes[len++] = temp2[0];
// Get the MAC address (0x0D)
var temp4 = BitConverter.GetBytes(recipient.MacAddress);
sendBytes[len++] = 0x01; // MAC address length - adjust for other lengths ...
sendBytes[len++] = temp4[0];
sendBytes[len++] = 0xFF; // Hop count = 255
}
// APDU
sendBytes[len++] = 0x00; // Control flags
sendBytes[len++] = 0x05; // Max APDU length (1476)
// Create invoke counter
sendBytes[len++] = (byte)(invokeCounter);
invokeCounter = ((invokeCounter + 1) & 0xFF);
sendBytes[len++] = 0x0C; // Service Choice: Read Property request
// Service Request (var part of APDU):
// Set up Object ID (Context Tag)
len = Apdu.SetObjectId(ref sendBytes, len, objtype, recipient.Instance);
// Set up Property ID (Context Tag)
len = Apdu.SetPropertyId(ref sendBytes, len, objprop);
// Optional array index goes here
if (arrayidx >= 0)
{
len = Apdu.SetArrayIdx(ref sendBytes, len, arrayidx);
}
// Fix the BVLL length
sendBytes[3] = (byte)len;
var getResponse = false;
var count = 0;
while (count < BacnetUnicastRequestRepeatCount && !getResponse)
{
sendUdp.EnableBroadcast = false;
sendUdp.Send(sendBytes, (int)len, recipient.ServerEp);
while (!getResponse)
{
if (sendUdp.Client.Available <= 0)
{
continue;
}
//recvBytes = SendUDP.Receive(ref RemoteEP);
var sendTo = recipient.ServerEp;
var recvBytes = sendUdp.Receive(ref sendTo);
var apduOffset = Npdu.Parse(recvBytes, Bvlc.BacnetBvlcHeaderLen); // BVLL is always 4 bytes
// Check for APDU response
// 0x - Confirmed Request
// 1x - Un-Confirmed Request
// 2x - Simple ACK
// 3x - Complex ACK
// 4x - Segment ACK
// 5x - Error
// 6x - Reject
// 7x - Abort
if (recvBytes[apduOffset] != 0x30)
{
continue;
}
// Verify the Invoke ID is the same
var ic = (byte)(invokeCounter == 0 ? 255 : invokeCounter - 1);
if (ic != recvBytes[apduOffset + 1])
{
continue;
}
Apdu.ParseProperty(ref recvBytes, apduOffset, property);
getResponse = true; // This will still execute the finally
}
count++;
}
return(getResponse);
}
