private IEnumerable <Task> OnReadResponseAsync(IModbusClientRequest request)
{
var bytesToRead = ProtocolConstants.MBAP_HEADER_LENGTH;
var mbapHeader = new byte[bytesToRead];
var numBytesRead = 0;
while (numBytesRead != ProtocolConstants.MBAP_HEADER_LENGTH)
{
var readTask = this._transport.ReadAsync(mbapHeader, numBytesRead, bytesToRead - numBytesRead);
yield return(readTask);
numBytesRead = readTask.Result;
if (numBytesRead == 0)
{
this._logger.Log(ResourceConstants.TCP_MODBUS_READ_RESULT_WITH_ZERO_BYTES_MESSAGE, Category.ERROR, Priority.HIGH);
Guard.Throw <ClientModbusResponseException>(
ResourceConstants.TCP_MODBUS_READ_RESULT_WITH_ZERO_BYTES_MESSAGE);
}
}
bytesToRead = (ushort)(mbapHeader[5] | (mbapHeader[4] << 8));
var frame = new byte[bytesToRead];
numBytesRead = 0;
while (numBytesRead != bytesToRead)
{
var readTask = this._transport.ReadAsync(frame, numBytesRead, bytesToRead - numBytesRead);
yield return(readTask);
numBytesRead = readTask.Result;
if (numBytesRead == 0)
{
this._logger.Log(ResourceConstants.TCP_MODBUS_READ_RESULT_WITH_ZERO_BYTES_MESSAGE, Category.ERROR, Priority.HIGH);
Guard.Throw <ClientModbusResponseException>(
ResourceConstants.TCP_MODBUS_READ_RESULT_WITH_ZERO_BYTES_MESSAGE);
}
}
var response = request.CreateResponseFromFrame(mbapHeader.CombineArray(frame));
yield return(Task.Factory.FromResult(response));
}
/// <summary>
/// Reads a modbus response from a transport.
/// </summary>
/// <param name="request"></param>
/// <returns>An instance of a modbus response that has recently been read.</returns>
protected override IModbusResponse ReadResponse(IModbusClientRequest request)
{
var requestResponse = this.ReadResponseInternal();
return(request.CreateResponseFromFrame(requestResponse));
}
