public void CrcTest()
{
Assert.AreEqual(
ModbusHelper.CRC16(new byte[] { 0, 0, 1, 1, 2, 3, 4, 5, 0, 0 }, 2, 6),
ModbusHelper.CRC16(new byte[] { 1, 1, 2, 3, 4, 5, 0, 0 }, 0, 6)
);
}
public void FillResponse(byte[] response, int offset, object value)
{
Wrapped.FillResponse(response, offset, value);
var crc = ModbusHelper.CRC16(response, offset, Wrapped.ResponseLength);
response[offset + Wrapped.ResponseLength + 0] = ModbusHelper.Low(crc);
response[offset + Wrapped.ResponseLength + 1] = ModbusHelper.High(crc);
}
public void FillRequest(byte[] request, int offset)
{
Wrapped.FillRequest(request, offset);
var crc = ModbusHelper.CRC16(request, offset, Wrapped.RequestLength);
request[offset + Wrapped.RequestLength + 0] = ModbusHelper.Low(crc);
request[offset + Wrapped.RequestLength + 1] = ModbusHelper.High(crc);
}
public IModbusWrapper Parse(byte[] request, int offset)
{
var wrapped = ModbusParser.Parse(request, offset);
var crc = ModbusHelper.CRC16(request, offset, wrapped.RequestLength);
Assert.Equal(crc, ModbusHelper.GetUShortLittleEndian(request, offset + wrapped.RequestLength),
"CRC mismatch {0:X4} expected {1:X4}");
return(new ModbusRTUWrapper(wrapped));
}
public object ParseResponse(byte[] response, int offset)
{
var crc1 = ModbusHelper.CRC16(response, offset, Wrapped.ResponseLength);
//crc is little endian page 13 http://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
var crc2 = ModbusHelper.GetUShortLittleEndian(response, offset + Wrapped.ResponseLength);
Assert.Equal(crc2, crc1, "CRC mismatch got {0:X4} expected {1:X4}");
return(Wrapped.ParseResponse(response, offset));
}
public byte[] GetException(byte code)
{
var exception = new byte[5];
exception[0] = Wrapped.Slave;
exception[1] = (byte)(Wrapped.Code | 0x80);
exception[2] = code;
var crc = ModbusHelper.CRC16(exception, 0, 3);
exception[3] = ModbusHelper.Low(crc);
exception[4] = ModbusHelper.High(crc);
return(exception);
}
public void CheckException(byte[] response, int count)
{
if (count < 5)
{
Thrower.Throw("Partial exception packet got {0} expected >= {1}", count, 5);
}
var offset = 0;
var code = response[offset + 1];
if ((code & 0x80) != 0)
{
Assert.Equal(response[offset + 0], Wrapped.Slave, "Slave mismatch got {0} expected {1}");
Assert.Equal(code & 0x7F, Wrapped.Code, "Code mismatch got {0} expected {1}");
var crc1 = ModbusHelper.CRC16(response, offset, 3);
//crc is little endian page 13 http://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
var crc2 = ModbusHelper.GetUShortLittleEndian(response, offset + 3);
Assert.Equal(crc2, crc1, "CRC mismatch got {0:X4} expected {1:X4}");
throw new ModbusException(response[offset + 2]);
}
}