internal static byte[] ReadRequestResponse(ICommChannel streamResource)
{
// read header
var mbapHeader = new byte[6];
int numBytesRead = 0;
while (numBytesRead != 6)
{
int bRead = streamResource.Read(mbapHeader, numBytesRead, 6 - numBytesRead);
if (bRead == 0)
{
throw new IOException("Read resulted in 0 bytes returned.");
}
numBytesRead += bRead;
}
Debug.WriteLine($"MBAP header: {string.Join(", ", mbapHeader)}");
var frameLength = (ushort)IPAddress.HostToNetworkOrder(BitConverter.ToInt16(mbapHeader, 4));
Debug.WriteLine($"{frameLength} bytes in PDU.");
// read message
var messageFrame = new byte[frameLength];
numBytesRead = 0;
while (numBytesRead != frameLength)
{
int bRead = streamResource.Read(messageFrame, numBytesRead, frameLength - numBytesRead);
if (bRead == 0)
{
throw new IOException("Read resulted in 0 bytes returned.");
}
numBytesRead += bRead;
}
Debug.WriteLine($"PDU: {frameLength}");
var frame = mbapHeader.Concat(messageFrame).ToArray();
Debug.WriteLine($"RX: {string.Join(", ", frame)}");
return(frame);
}
internal static string ReadLine(ICommChannel stream)
{
var result = new StringBuilder();
var singleByteBuffer = new byte[1];
do
{
if (stream.Read(singleByteBuffer, 0, 1) == 0)
{
continue;
}
result.Append(Encoding.UTF8.GetChars(singleByteBuffer).First());
}while (!result.ToString().EndsWith(Modbus.NewLine));
return(result.ToString().Substring(0, result.Length - Modbus.NewLine.Length));
}
