/// <summary>
/// Reads an array of FLOAT32, INT32, DOUBLE64 or ASCII (char) values form the device.
/// The data length is given by the device.
/// This method does only return when the device tells the host, that all data is read.
/// The data is read in an loop with several sub queries.
/// During this command is working, it is possible to use other commands with an different thread.
/// </summary>
/// <param name="address">Device Address. Use null to use the DefaultDeviceAddress defined on MeComQuerySet.</param>
/// <param name="parameterId">Device Parameter ID.</param>
/// <param name="instance">Parameter Instance. (usually 1)</param>
/// <param name="type">Specifies the type of the value to be read.</param>
/// <param name="callback">Is called every time when the progress has changed.</param>
/// <param name="expectedNrOfElements">Defines the expected number of elements to calculate the progress for the callback function.</param>
/// <returns>Returned value.</returns>
/// <exception cref="ComCommandException">when the command fails. Check the inner exception for details.</exception>
public dynamic GetBigData(byte?address, UInt16 parameterId, byte instance, MeParType type, ProgressUpdateCallback callback = null, int expectedNrOfElements = 0)
{
dynamic value;
try
{
ushort rcvElements;
bool hasMoreData;
uint totalReadElements = 0;
MemoryStream totalStream = new MemoryStream();
do
{
MeComPacket txFrame = new MeComPacket('#', address);
MeComVarConvert.AddString(txFrame.Payload, "?VB");
MeComVarConvert.AddUint16(txFrame.Payload, parameterId);
MeComVarConvert.AddUint8(txFrame.Payload, instance);
MeComVarConvert.AddUint32(txFrame.Payload, totalReadElements); //Read start position
MeComVarConvert.AddUint16(txFrame.Payload, UInt16.MaxValue); //Maximum Elements to read per call.
MeComPacket rxFrame = meQuerySet.Query(txFrame);
rcvElements = MeComVarConvert.ReadUint16(rxFrame.Payload);
hasMoreData = MeComVarConvert.ReadUint8(rxFrame.Payload) == 1;
totalReadElements += rcvElements;
if (rcvElements > 0)
{
rxFrame.Payload.CopyTo(totalStream);
}
callback?.Invoke(100.0 / expectedNrOfElements * totalReadElements);
} while (hasMoreData);
totalStream.Position = 0;
callback?.Invoke(100);
switch (type)
{
case MeParType.FLOAT32:
value = new float[totalReadElements];
break;
case MeParType.INT32:
value = new int[totalReadElements];
break;
case MeParType.DOUBLE64:
value = new double[totalReadElements];
break;
case MeParType.LATIN1:
value = "";
break;
case MeParType.BYTE:
value = new byte[totalReadElements];
break;
default:
throw new ArgumentOutOfRangeException("Unknown EParType: " + type);
}
for (int i = 0; i < totalReadElements; i++)
{
switch (type)
{
case MeParType.FLOAT32:
value[i] = MeComVarConvert.ReadFloat32(totalStream);
break;
case MeParType.INT32:
value[i] = MeComVarConvert.ReadInt32(totalStream);
break;
case MeParType.DOUBLE64:
value[i] = MeComVarConvert.ReadDouble64(totalStream);
break;
case MeParType.LATIN1:
value = MeComVarConvert.ReadEncodedString(totalStream, (int)totalReadElements);
return(value);
case MeParType.BYTE:
value[i] = MeComVarConvert.ReadUint8(totalStream);
break;
default:
throw new ArgumentOutOfRangeException("Unknown EParType: " + type);
}
}
return(value);
}
catch (Exception Ex)
{
throw new ComCommandException(String.Format("Get Value failed: Address: {0}; ID: {1}; Inst: {2}; Detail: {3}", address, parameterId, instance, Ex.Message), Ex);
}
}
private void DecodeFrame(ref MeComPacket RxFrame, byte c, ref MemoryStream LocalRxBuf)
{
try
{
if (c == Convert.ToByte('!'))
{
//Start indicator
LocalRxBuf = new MemoryStream();
LocalRxBuf.WriteByte(c);
}
else
{
if (c == 0x0D && (LocalRxBuf?.Length >= 11))
{
//End of Frame received
if (LocalRxBuf.Length == 11)
{
//ACK Received
LocalRxBuf.Position = 7;
ushort rcvCRC = MeComVarConvert.ReadUint16(LocalRxBuf);
if (rcvCRC == LastCRC)
{
//Valid Ack received --> Extract Data
LocalRxBuf.Position = 1;
RxFrame.Address = MeComVarConvert.ReadUint8(LocalRxBuf);
RxFrame.SeqNr = MeComVarConvert.ReadUint16(LocalRxBuf);
RxFrame.RcvType = ERcvType.ACK;
statistics.IncRxFrames();
}
}
else
{
//Data Frame received
LocalRxBuf.Position = LocalRxBuf.Length - 4;
ushort rcvCRC = MeComVarConvert.ReadUint16(LocalRxBuf);
//Cut received CRC form stream and recalc CRC
LocalRxBuf.SetLength(LocalRxBuf.Length - 4);
ushort calcCRC = CalcCRC_CITT(LocalRxBuf);
if (calcCRC == rcvCRC)
{
LocalRxBuf.Position = 1;
RxFrame.Address = MeComVarConvert.ReadUint8(LocalRxBuf);
RxFrame.SeqNr = MeComVarConvert.ReadUint16(LocalRxBuf);
RxFrame.Payload = new MemoryStream();
LocalRxBuf.CopyTo(RxFrame.Payload);
RxFrame.Payload.Position = 0; //Reset position for the user
RxFrame.RcvType = ERcvType.Data;
statistics.IncRxFrames();
}
else
{
statistics.IncCrcErrors();
}
}
}
else
{
LocalRxBuf?.WriteByte(c);
}
}
}
catch (ArgumentOutOfRangeException)
{
//Just ignore. They are thrown from MeComVarConvert
}
}