public CoLaBTelegram SendTelegram(CoLaCommandType commandType, string commandName, Action <BinaryWriter> writeTelegram, int acknowledgeTimeout)
{
// Convert the Command-Type to a String
string commandString;
string acknowledgeType;
switch (commandType)
{
case CoLaCommandType.Read: commandString = $"sRN " + commandName; acknowledgeType = "sRA"; break;
case CoLaCommandType.Write: commandString = $"sWN " + commandName; acknowledgeType = "sWA"; break;
case CoLaCommandType.Method: commandString = $"sMN " + commandName; acknowledgeType = "sAN"; break;
case CoLaCommandType.Event: commandString = $"sEN " + commandName; acknowledgeType = "sEA"; break;
default: throw new ArgumentException("Unknown or unsupported CoLa command type: " + commandType.ToString(), nameof(commandType));
}
// Initialize the Upstream Buffer on first telegram
if (null == _upstreamWriter)
{
_upstreamBuffer = new MemoryStream();
_upstreamWriter = new BinaryWriter(_upstreamBuffer, Encoding.ASCII);
_upstreamWriter.Write(new byte[] { _stx, _stx, _stx, _stx, 0x00, 0x00, 0x00, 0x00 });
}
else
{
_upstreamBuffer.Seek(8, SeekOrigin.Begin);
}
// Generate the Telegram
_upstreamWriter.Write(Encoding.ASCII.GetBytes(commandString));
if (null != writeTelegram)
{
_upstreamWriter.Write(_space);
writeTelegram(_upstreamWriter);
}
int length = (int)(_upstreamBuffer.Position - 8L);
// Encode the Telegram Size
_upstreamBuffer.Seek(4, SeekOrigin.Begin);
for (int i = 3; i >= 0; --i)
{
_upstreamWriter.Write((byte)(length >> (i * 8)));
}
// Calculate the Telegram Checksum
byte checksum = 0;
for (int i = 0; i < length; ++i)
{
checksum ^= (byte)_upstreamBuffer.ReadByte();
}
_upstreamWriter.Write(checksum);
// Send the Telegram
_client.Client.Send(_upstreamBuffer.GetBuffer(), 0, (int)_upstreamBuffer.Position, SocketFlags.None);
// Look for Acknowledgement
_client.Client.ReceiveTimeout = acknowledgeTimeout;
CoLaBTelegram acknowledgement;
try
{
acknowledgement = ReceiveTelegram();
}
catch (SocketException socketException)
{
switch (socketException.SocketErrorCode)
{
// Timeouts indicate that the port is not configured for the binary dialect
case SocketError.TimedOut:
throw new CoLaBException($"Upstream CoLa (binary) Telegram not acknowledged: CoLa (binary) dialect ignored", socketException);
// Other socket errors are unknown
default:
throw new CoLaBException($"Upstream CoLa (binary) Telegram not acknowledged: socket error", socketException);
}
}
if ((null == acknowledgement) || (acknowledgement.CommandPrefix != acknowledgeType) || (acknowledgement.CommandName != commandName))
{
throw new CoLaBException($"Upstream CoLa (binary) Telegram acknowledged incorrectly: expected `{acknowledgeType} {commandName}`");
}
return(acknowledgement);
}
public CoLaBTelegram SendTelegram(CoLaCommandType commandType, string commandName, int acknowledgeTimeout)
{
return(SendTelegram(commandType, commandName, writeTelegram: null, acknowledgeTimeout: acknowledgeTimeout));
}