protected override IList <byte> Read(int length)
{
return(_tcpHelper.Read(length));
}
private List <byte> ReadBlock(int address, int length, byte code)
{
_tcpHelper.Write(
new byte[]
{
0x50, 0x00, //Header
_networkNumber, //Network number
_pcNumber, //PC number
0xFF, 0x03, //Dest module I/O number
0x00, //Dest module station number
0x0C, 0x00, //Request length
0x0A, 0x00, //CPU timer
0x01, 0x04, //Command
0x00, 0x00, //Subcommand
(byte)(address & 0xFF), (byte)((address & 0xFF00) >> 8),
(byte)((address & 0xFF0000) >> 16), //Address
code,
(byte)(length & 0xFF), (byte)((length & 0xFF00) >> 8) // number of device points
});
var bytesToReceive = length * 2;
const int headerLength = 11;
var messageLengthToReceive = bytesToReceive + headerLength;
var answer = _tcpHelper.Read(messageLengthToReceive);
if (answer == null)
{
throw new Exception("Message not received");
}
if (answer.Count < 11)
{
throw new Exception("Recieved message size error");
}
var responseCode = (int)answer[10];
responseCode = responseCode << 8;
responseCode = responseCode | answer[9];
if (responseCode != 0)
{
throw new Exception("Response code 0x" + responseCode.ToString("X"));
}
if (answer.Count != messageLengthToReceive)
{
throw new Exception("Recieved message size error 1");
}
var someLength = (int)answer[8];
someLength = someLength << 8;
someLength = someLength | answer[7];
if (someLength != messageLengthToReceive - 9)
{
throw new Exception("Recieved message size error 2");
}
var data = new List <byte>(bytesToReceive);
for (var i = 0; i < bytesToReceive; ++i)
{
data.Add(answer[headerLength + i]);
}
return(data);
}