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);
}
protected override async Task <SendMessageResult> SendMessageAsync(ReadOnlyMemory <byte> message, int timeout, CancellationToken cancellationToken)
{
SendMessageResult result = new SendMessageResult
{
Bytes = 0,
Packets = 0,
};
try
{
result.Bytes += await _client.SendAsync(message, timeout, cancellationToken);
result.Packets += 1;
}
catch (ObjectDisposedException)
{
throw new OmronException("Failed to Send FINS Message to Omron PLC '" + RemoteHost + ":" + Port + "' - The underlying Socket Connection has been 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 initializeClient(int timeout, CancellationToken cancellationToken)
{
_client = new TcpClient(RemoteHost, Port);
await _client.ConnectAsync(timeout, cancellationToken);
try
{
// Send Auto-Assign Client Node Request
SendMessageResult sendResult = await sendMessageAsync(enTCPCommandCode.NodeAddressToPLC, new byte[4], timeout, cancellationToken);
// Receive Client Node ID
ReceiveMessageResult receiveResult = await receiveMessageAsync(enTCPCommandCode.NodeAddressFromPLC, timeout, cancellationToken);
if (receiveResult.Message.Length < 8)
{
throw new OmronException("Failed to Negotiate a TCP Connection with Omron PLC '" + RemoteHost + ":" + Port + "' - TCP Negotiation Message Length was too Short");
}
byte[] tcpNegotiationMessage = receiveResult.Message.Slice(0, 8).ToArray();
if (tcpNegotiationMessage[3] == 0 || tcpNegotiationMessage[3] == 255)
{
throw new OmronException("Failed to Negotiate a TCP Connection with Omron PLC '" + RemoteHost + ":" + Port + "' - TCP Negotiation Message contained an Invalid Local Node ID");
}
_localNodeId = tcpNegotiationMessage[3];
if (tcpNegotiationMessage[7] == 0 || tcpNegotiationMessage[7] == 255)
{
throw new OmronException("Failed to Negotiate a TCP Connection with Omron PLC '" + RemoteHost + ":" + Port + "' - TCP Negotiation Message contained an Invalid Remote Node ID");
}
_remoteNodeId = tcpNegotiationMessage[7];
}
catch (OmronException e)
{
throw new OmronException("Failed to Negotiate a TCP Connection with Omron PLC '" + RemoteHost + ":" + Port + "'", e);
}
}
internal async Task <ProcessRequestResult> ProcessRequestAsync(FINSRequest request, int timeout, int retries, CancellationToken cancellationToken)
{
int attempts = 0;
Memory <byte> responseMessage = new Memory <byte>();
int bytesSent = 0;
int packetsSent = 0;
int bytesReceived = 0;
int packetsReceived = 0;
DateTime startTimestamp = DateTime.UtcNow;
while (attempts <= retries)
{
try
{
if (!_semaphore.Wait(0))
{
await _semaphore.WaitAsync(cancellationToken);
}
if (attempts > 0)
{
await DestroyAndInitializeClient(timeout, cancellationToken);
}
// Build the Request into a Message we can Send
ReadOnlyMemory <byte> requestMessage = request.BuildMessage(getNextRequestId());
// Send the Message
SendMessageResult sendResult = await SendMessageAsync(requestMessage, timeout, cancellationToken);
bytesSent += sendResult.Bytes;
packetsSent += sendResult.Packets;
// Receive a Response
ReceiveMessageResult receiveResult = await ReceiveMessageAsync(timeout, cancellationToken);
bytesReceived += receiveResult.Bytes;
packetsReceived += receiveResult.Packets;
responseMessage = receiveResult.Message;
break;
}
catch (Exception)
{
if (attempts >= retries)
{
throw;
}
}
finally
{
_semaphore.Release();
}
// Increment the Attempts
attempts++;
}
try
{
return(new ProcessRequestResult
{
BytesSent = bytesSent,
PacketsSent = packetsSent,
BytesReceived = bytesReceived,
PacketsReceived = packetsReceived,
Duration = DateTime.UtcNow.Subtract(startTimestamp).TotalMilliseconds,
Response = FINSResponse.CreateNew(responseMessage, request),
});
}
catch (FINSException e)
{
if (e.Message.Contains("Service ID") && responseMessage.Length >= 9 && responseMessage.Span[9] != request.ServiceID)
{
try
{
if (!_semaphore.Wait(0))
{
await _semaphore.WaitAsync(cancellationToken);
}
await PurgeReceiveBuffer(timeout, cancellationToken);
}
catch
{
}
finally
{
_semaphore.Release();
}
}
throw new OmronException("Received a FINS Error Response from Omron PLC '" + _remoteHost + ":" + _port + "'", e);
}
}
