// ------------------------------------------------------------------------
// Write asynchronous data acknowledge
private void OnSend(System.IAsyncResult result)
{
if (result.IsCompleted == false)
{
throw ModbusException.GetModbusException(0xFD);
}
}
protected override byte[] CheckResponse(byte[] respRaw, int respRawLength)
{
if (respRawLength < 13)
{
throw new InvalidResponseTelegramException("Error: Invalid response telegram, did not receive minimal length of 13 bytes");
}
if ((respRaw[0] != StartOfFrame) | (respRaw[respRawLength - 2] != EndOfFrame1) | (respRaw[respRawLength - 1] != EndOfFrame2))
{
throw new InvalidResponseTelegramException("Error: Invalid response telegram. No Start of Frame or End of Frame.");
}
// Convert ASCII telegram to binary
byte[] buffer = new byte[(respRawLength - 3) / 2];
byte high, low, val;
for (int i = 0; i < buffer.Length; i++)
{
//Example : Char1 = 0x35 ('5') and Char2 = 0x42 ('B') compressed to Byte = 0x5B
val = respRaw[(2 * i) + 1];
high = (val <= 0x39) ? (byte)(val - 0x30) : (byte)(val - 0x37);
val = respRaw[(2 * i) + 2];
low = (val <= 0x39) ? (byte)(val - 0x30) : (byte)(val - 0x37);
buffer[i] = (byte)((byte)(high << 4) | low);
}
// Calculate LRC
byte lrc = 0;
for (int i = 0; i < buffer.Length - 1; i++)
{
lrc += buffer[i];
}
lrc = (byte)(lrc * (-1));
// Check LRC
if (buffer[buffer.Length - 1] != lrc)
{
throw new InvalidResponseTelegramException("Error: Invalid response telegram, LRC check failed");
}
if (IsModbusException(buffer[1]))
{
throw ModbusException.GetModbusException(buffer[2]);
}
// Strip LRC and copy response PDU into output buffer
byte[] responsePdu = new byte[buffer.Length - 1];
for (int i = 0; i < responsePdu.Length; i++)
{
responsePdu[i] = buffer[i];
}
return(responsePdu);
}
// ------------------------------------------------------------------------
// Write data and and wait for response
private byte[] WriteSyncData(byte[] write_data, ushort id)
{
if (tcpSynCl.Connected)
{
try
{
tcpSynCl.Send(write_data, 0, write_data.Length, SocketFlags.None);
int result = tcpSynCl.Receive(tcpSynClBuffer, 0, tcpSynClBuffer.Length, SocketFlags.None);
byte unit = tcpSynClBuffer[6];
byte function = tcpSynClBuffer[7];
byte[] data;
if (result == 0)
{
throw ModbusException.GetModbusException(0xFD);
}
// ------------------------------------------------------------
// Response data is slave exception
if (function > 128)
{
throw ModbusException.GetModbusException(0xA1);
}
// ------------------------------------------------------------
// Write response data
else if ((function >= (byte)EnumModbusFunctionCode.WriteSingleCoil) && (function != (byte)EnumModbusFunctionCode.ReadWriteMultipleRegisters))
{
data = new byte[2];
Array.Copy(tcpSynClBuffer, 10, data, 0, 2);
}
// ------------------------------------------------------------
// Read response data
else
{
data = new byte[tcpSynClBuffer[8]];
Array.Copy(tcpSynClBuffer, 9, data, 0, tcpSynClBuffer[8]);
}
return(data);
}
catch (SystemException)
{
throw ModbusException.GetModbusException(0xFD);
}
}
else
{
throw ModbusException.GetModbusException(0xFD);
}
}
// ------------------------------------------------------------------------
// Write asynchronous data
private void WriteAsyncData(byte[] write_data, ushort id)
{
if ((tcpAsyCl != null) && (tcpAsyCl.Connected))
{
try
{
tcpAsyCl.BeginSend(write_data, 0, write_data.Length, SocketFlags.None, new AsyncCallback(OnSend), null);
tcpAsyCl.BeginReceive(tcpAsyClBuffer, 0, tcpAsyClBuffer.Length, SocketFlags.None, new AsyncCallback(OnReceive), tcpAsyCl);
}
catch (SystemException)
{
throw ModbusException.GetModbusException(0xFD);
}
}
else
{
throw ModbusException.GetModbusException(0xFD);
}
}
// ------------------------------------------------------------------------
// Write asynchronous data response
private void OnReceive(System.IAsyncResult result)
{
if (result.IsCompleted == false)
{
throw ModbusException.GetModbusException(0xFD);
}
ushort id = SwapUInt16(BitConverter.ToUInt16(tcpAsyClBuffer, 0));
byte unit = tcpAsyClBuffer[6];
byte function = tcpAsyClBuffer[7];
byte[] data;
// ------------------------------------------------------------
// Write response data
if ((function >= (byte)EnumModbusFunctionCode.WriteSingleCoil) && (function != (byte)EnumModbusFunctionCode.ReadWriteMultipleRegisters))
{
data = new byte[2];
Array.Copy(tcpAsyClBuffer, 10, data, 0, 2);
}
// ------------------------------------------------------------
// Read response data
else
{
data = new byte[tcpAsyClBuffer[8]];
Array.Copy(tcpAsyClBuffer, 9, data, 0, tcpAsyClBuffer[8]);
}
// ------------------------------------------------------------
// Response data is slave exception
if (function > 128)
{
throw ModbusException.GetModbusException(0xA1);
}
// ------------------------------------------------------------
// Response data is regular data
else if (OnResponseData != null)
{
OnResponseData(id, unit, function, data);
}
}