/// <summary>
/// Sends a command to the serial port. The first byte is sent as is, but
/// all other successive bytes are expanded to two "Kamstrup bytes".
/// </summary>
/// <returns>
/// The command.
/// </returns>
/// <param name='data'>
/// Data.
/// </param>
/// <param name='log'>
/// Log.
/// </param>
public byte[] SendCommand(byte[] data)
{
byte[] payload = ToKamstrupBytes(data.Subset(MAGICBYTE_LENGTH));
byte[] checksum = ToKamstrupPair(Checksum(data.Subset(MAGICBYTE_LENGTH)));
return(device.SendCommand(data.Subset(0, MAGICBYTE_LENGTH).Merge(payload, checksum)));
}
private Dictionary <string, string> Fetch()
{
var results = new Dictionary <string, string>();
byte[] reply = connection.SendCommand(Encoding.ASCII.GetBytes(DOWNLOAD_METERDATA));
string stringReply = Encoding.ASCII.GetString(reply);
results.Add("MAKE", stringReply.Substring(1, 3));
results.Add("MODEL", stringReply.Substring(5));
if (connection.ReadByte() != STX)
{
throw new MeterException("STX expected!");
}
int checksum = 0;
String input;
int i = 2;
do
{
input = connection.ReadLine();
string[] parts = input.Split("(".ToCharArray());
if (parts.Length == 2)
{
results.Add(parts[0], parts[1].Substring(0, parts[1].IndexOf(")")));
}
else
{
results.Add("#" + i, input);
}
foreach (char value in input)
{
checksum += value;
}
checksum += CR;
i++;
}while(!input.Contains("!")); // TODO: Replace by EndsWith(..)?
int etx = connection.ReadByte();
if (etx != ETX)
{
throw new MeterException("ETX expected!");
}
checksum += etx;
checksum &= 0x7F; // Remove anything but the 7 LSB's
if (connection.ReadByte() != checksum)
{
throw new MeterException("Invalid checksum!");
}
return(results);
}