private ReadOnlyMemory <byte> buildFinsTcpMessage(enTCPCommandCode command, ReadOnlyMemory <byte> message)
{
List <byte> tcpMessage = new List <byte>();
// FINS Message Identifier
tcpMessage.Add((byte)'F');
tcpMessage.Add((byte)'I');
tcpMessage.Add((byte)'N');
tcpMessage.Add((byte)'S');
// Length of Message
tcpMessage.AddRange(BitConverter.GetBytes(Convert.ToUInt32(4 + 4 + message.Length)).Reverse()); // Command + Error Code + Message Data
// Command
tcpMessage.Add(0);
tcpMessage.Add(0);
tcpMessage.Add(0);
tcpMessage.Add((byte)command);
// Error Code
tcpMessage.Add(0);
tcpMessage.Add(0);
tcpMessage.Add(0);
tcpMessage.Add(0);
tcpMessage.AddRange(message.ToArray());
return(tcpMessage.ToArray());
}
private async Task <SendMessageResult> sendMessageAsync(enTCPCommandCode command, ReadOnlyMemory <byte> message, int timeout, CancellationToken cancellationToken)
{
SendMessageResult result = new SendMessageResult
{
Bytes = 0,
Packets = 0,
};
ReadOnlyMemory <byte> tcpMessage = buildFinsTcpMessage(command, message);
try
{
result.Bytes += await _client.SendAsync(tcpMessage, timeout, cancellationToken);
result.Packets += 1;
}
catch (ObjectDisposedException)
{
throw new OmronException("Failed to Send FINS Message to Omron PLC '" + RemoteHost + ":" + Port + "' - The underlying Socket Connection was Closed");
}
catch (TimeoutException)
{
throw new OmronException("Failed to Send FINS Message within the Timeout Period to Omron PLC '" + RemoteHost + ":" + Port + "'");
}
catch (System.Net.Sockets.SocketException e)
{
throw new OmronException("Failed to Send FINS Message to Omron PLC '" + RemoteHost + ":" + Port + "'", e);
}
return(result);
}
private async Task <ReceiveMessageResult> receiveMessageAsync(enTCPCommandCode command, int timeout, CancellationToken cancellationToken)
{
ReceiveMessageResult result = new ReceiveMessageResult
{
Bytes = 0,
Packets = 0,
Message = new Memory <byte>(),
};
try
{
List <byte> receivedData = new List <byte>();
DateTime startTimestamp = DateTime.UtcNow;
while (DateTime.UtcNow.Subtract(startTimestamp).TotalMilliseconds < timeout && receivedData.Count < TCP_HEADER_LENGTH)
{
Memory <byte> buffer = new byte[4096];
TimeSpan receiveTimeout = TimeSpan.FromMilliseconds(timeout).Subtract(DateTime.UtcNow.Subtract(startTimestamp));
if (receiveTimeout.TotalMilliseconds >= 50)
{
int receivedBytes = await _client.ReceiveAsync(buffer, receiveTimeout, cancellationToken);
if (receivedBytes > 0)
{
receivedData.AddRange(buffer.Slice(0, receivedBytes).ToArray());
result.Bytes += receivedBytes;
result.Packets += 1;
}
}
}
if (receivedData.Count == 0)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - No Data was Received");
}
if (receivedData.Count < TCP_HEADER_LENGTH)
{
throw new OmronException("Failed to Receive FINS Message within the Timeout Period from Omron PLC '" + RemoteHost + ":" + Port + "'");
}
if (receivedData[0] != 'F' || receivedData[1] != 'I' || receivedData[2] != 'N' || receivedData[3] != 'S')
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - The TCP Header was Invalid");
}
byte[] tcpHeader = receivedData.GetRange(0, TCP_HEADER_LENGTH).ToArray();
int tcpMessageDataLength = (int)BitConverter.ToUInt32(new byte[] { receivedData[7], receivedData[6], receivedData[5], receivedData[4] }) - 8;
if (tcpMessageDataLength <= 0 || tcpMessageDataLength > short.MaxValue)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - The TCP Message Length was Invalid");
}
if (receivedData[11] == 3 || receivedData[15] != 0)
{
switch (receivedData[15])
{
case 1:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: The FINS Identifier (ASCII Code) was Invalid.");
case 2:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: The Data Length is too Long.");
case 3:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: The Command is not Supported.");
case 20:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: All Connections are in Use.");
case 21:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: The Specified Node is already Connected.");
case 22:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: Attempt to Access a Protected Node from an Unspecified IP Address.");
case 23:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: The Client FINS Node Address is out of Range.");
case 24:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: The same FINS Node Address is being used by the Client and Server.");
case 25:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: All the Node Addresses Available for Allocation have been Used.");
default:
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - Omron TCP Error: Unknown Code '" + receivedData[15] + "'");
}
}
if (receivedData[8] != 0 || receivedData[9] != 0 || receivedData[10] != 0 || receivedData[11] != (byte)command)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - The TCP Command Received '" + receivedData[11] + "' did not match Expected Command '" + (byte)command + "'");
}
if (command == enTCPCommandCode.FINSFrame && tcpMessageDataLength < FINSResponse.HEADER_LENGTH + FINSResponse.COMMAND_LENGTH + FINSResponse.RESPONSE_CODE_LENGTH)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - The TCP Message Length was too short for a FINS Frame");
}
receivedData.RemoveRange(0, TCP_HEADER_LENGTH);
if (receivedData.Count < tcpMessageDataLength)
{
startTimestamp = DateTime.UtcNow;
while (DateTime.UtcNow.Subtract(startTimestamp).TotalMilliseconds < timeout && receivedData.Count < tcpMessageDataLength)
{
Memory <byte> buffer = new byte[4096];
TimeSpan receiveTimeout = TimeSpan.FromMilliseconds(timeout).Subtract(DateTime.UtcNow.Subtract(startTimestamp));
if (receiveTimeout.TotalMilliseconds >= 50)
{
int receivedBytes = await _client.ReceiveAsync(buffer, receiveTimeout, cancellationToken);
if (receivedBytes > 0)
{
receivedData.AddRange(buffer.Slice(0, receivedBytes).ToArray());
}
result.Bytes += receivedBytes;
result.Packets += 1;
}
}
}
if (receivedData.Count == 0)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - No Data was Received after TCP Header");
}
if (receivedData.Count < tcpMessageDataLength)
{
throw new OmronException("Failed to Receive FINS Message within the Timeout Period from Omron PLC '" + RemoteHost + ":" + Port + "'");
}
if (command == enTCPCommandCode.FINSFrame && receivedData[0] != 0xC0 && receivedData[0] != 0xC1)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - The FINS Header was Invalid");
}
result.Message = receivedData.ToArray();
}
catch (ObjectDisposedException)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "' - The underlying Socket Connection was Closed");
}
catch (TimeoutException)
{
throw new OmronException("Failed to Receive FINS Message within the Timeout Period from Omron PLC '" + RemoteHost + ":" + Port + "'");
}
catch (System.Net.Sockets.SocketException e)
{
throw new OmronException("Failed to Receive FINS Message from Omron PLC '" + RemoteHost + ":" + Port + "'", e);
}
return(result);
}
