/// <summary>
/// Decodes the response PDU.
/// </summary>
public virtual bool DecodeRespPDU(byte[] buffer, int offset, int length, out string errMsg)
{
errMsg = "";
bool result = false;
byte respFuncCode = buffer[offset];
if (respFuncCode == FuncCode)
{
if (length == RespPduLen)
{
result = true;
}
else
{
errMsg = ModbusPhrases.IncorrectPduLength;
}
}
else if (respFuncCode == ExcFuncCode)
{
errMsg = length == 2 ?
ModbusPhrases.DeviceError + ": " + ModbusUtils.GetExcDescr(buffer[offset + 1]) :
ModbusPhrases.IncorrectPduLength;
}
else
{
errMsg = ModbusPhrases.IncorrectPduFuncCode;
}
return(result);
}
private string reqDescr; // the request description
/// <summary>
/// Initializes a new instance of the class.
/// </summary>
public ElemGroup(DataBlock dataBlock)
: base(dataBlock)
{
reqDescr = "";
Elems = new List <Elem>();
ElemData = null;
StartTagIdx = -1;
SetFuncCode(ModbusUtils.GetReadFuncCode(dataBlock));
}
/// <summary>
/// Gets the element value according to its type, converted to double.
/// </summary>
public double GetElemVal(int elemIdx)
{
Elem elem = Elems[elemIdx];
byte[] elemData = ElemData[elemIdx];
byte[] buf;
// order bytes if needed
if (elem.ByteOrder == null)
{
buf = elemData;
}
else
{
buf = new byte[elemData.Length];
ModbusUtils.ApplyByteOrder(elemData, buf, elem.ByteOrder);
}
// calculate value
switch (elem.ElemType)
{
case ElemType.UShort:
return(BitConverter.ToUInt16(buf, 0));
case ElemType.Short:
return(BitConverter.ToInt16(buf, 0));
case ElemType.UInt:
return(BitConverter.ToUInt32(buf, 0));
case ElemType.Int:
return(BitConverter.ToInt32(buf, 0));
case ElemType.ULong: // possible data loss
return(BitConverter.ToUInt64(buf, 0));
case ElemType.Long: // possible data loss
return(BitConverter.ToInt64(buf, 0));
case ElemType.Float:
return(BitConverter.ToSingle(buf, 0));
case ElemType.Double:
return(BitConverter.ToDouble(buf, 0));
case ElemType.Bool:
return(buf[0] > 0 ? 1.0 : 0.0);
default:
return(0.0);
}
}
/// <summary>
/// Initializes the request ADU and calculates the response length.
/// </summary>
public virtual void InitReqADU(byte devAddr, TransMode transMode)
{
if (ReqPDU == null)
{
return;
}
int pduLen = ReqPDU.Length;
switch (transMode)
{
case TransMode.RTU:
ReqADU = new byte[pduLen + 3];
ReqADU[0] = devAddr;
Buffer.BlockCopy(ReqPDU, 0, ReqADU, 1, ReqPDU.Length);
ushort crc = ModbusUtils.CRC16(ReqADU, 0, pduLen + 1);
ReqADU[pduLen + 1] = (byte)(crc % 256);
ReqADU[pduLen + 2] = (byte)(crc / 256);
RespAduLen = RespPduLen + 3;
break;
case TransMode.ASCII:
byte[] aduBuf = new byte[pduLen + 2];
aduBuf[0] = devAddr;
Buffer.BlockCopy(ReqPDU, 0, aduBuf, 1, ReqPDU.Length);
aduBuf[pduLen + 1] = ModbusUtils.LRC(aduBuf, 0, pduLen + 1);
StringBuilder sbADU = new StringBuilder();
foreach (byte b in aduBuf)
{
sbADU.Append(b.ToString("X2"));
}
ReqADU = Encoding.ASCII.GetBytes(sbADU.ToString());
ReqStr = ModbusUtils.Colon + sbADU;
RespAduLen = RespPduLen + 2;
break;
default: // TransModes.TCP
ReqADU = new byte[pduLen + 7];
ReqADU[0] = 0;
ReqADU[1] = 0;
ReqADU[2] = 0;
ReqADU[3] = 0;
ReqADU[4] = (byte)((pduLen + 1) / 256);
ReqADU[5] = (byte)((pduLen + 1) % 256);
ReqADU[6] = devAddr;
Buffer.BlockCopy(ReqPDU, 0, ReqADU, 7, ReqPDU.Length);
RespAduLen = RespPduLen + 7;
break;
}
}
private string reqDescr; // the command description
/// <summary>
/// Initializes a new instance of the class.
/// </summary>
public ModbusCmd(DataBlock dataBlock, bool multiple)
: base(dataBlock)
{
if (dataBlock != DataBlock.Coils &&
dataBlock != DataBlock.HoldingRegisters &&
dataBlock != DataBlock.Custom)
{
throw new InvalidOperationException(ModbusPhrases.IllegalDataBlock);
}
reqDescr = "";
Multiple = multiple;
ElemType = ElemType.Undefined;
ElemCnt = 1;
ByteOrder = null;
CmdNum = 0;
CmdCode = "";
Value = 0;
Data = null;
SetFuncCode(ModbusUtils.GetWriteFuncCode(dataBlock, multiple));
}
/// <summary>
/// Initializes the request PDU and calculates the response length.
/// </summary>
public override void InitReqPDU()
{
if (DataBlock == DataBlock.Custom)
{
// build PDU for custom command
int dataLength = Data == null ? 0 : Data.Length;
ReqPDU = new byte[1 + dataLength];
ReqPDU[0] = FuncCode;
if (dataLength > 0)
{
Buffer.BlockCopy(Data, 0, ReqPDU, 1, dataLength);
}
RespPduLen = ReqPDU.Length; // assuming echo
}
else if (Multiple)
{
// build PDU for WriteMultipleCoils and WriteMultipleRegisters commands
int quantity; // quantity of registers
int dataLength; // data length in bytes
if (DataBlock == DataBlock.Coils)
{
quantity = ElemCnt;
dataLength = (ElemCnt % 8 == 0) ? ElemCnt / 8 : ElemCnt / 8 + 1;
}
else
{
quantity = ElemCnt * ModbusUtils.GetQuantity(ElemType);
dataLength = quantity * 2;
}
ReqPDU = new byte[6 + dataLength];
ReqPDU[0] = FuncCode;
ReqPDU[1] = (byte)(Address / 256);
ReqPDU[2] = (byte)(Address % 256);
ReqPDU[3] = (byte)(quantity / 256);
ReqPDU[4] = (byte)(quantity % 256);
ReqPDU[5] = (byte)dataLength;
ModbusUtils.ApplyByteOrder(Data, 0, ReqPDU, 6, dataLength, ByteOrder, false);
// set response length
RespPduLen = 5;
}
else
{
// build PDU for WriteSingleCoil and WriteSingleRegister commands
int dataLength = DataBlock == DataBlock.Coils ? 2 : ModbusUtils.GetDataLength(ElemType);
ReqPDU = new byte[3 + dataLength];
ReqPDU[0] = FuncCode;
ReqPDU[1] = (byte)(Address / 256);
ReqPDU[2] = (byte)(Address % 256);
if (DataBlock == DataBlock.Coils)
{
ReqPDU[3] = Value > 0 ? (byte)0xFF : (byte)0x00;
ReqPDU[4] = 0x00;
}
else
{
byte[] data = dataLength == 2 ?
new byte[] // standard Modbus
{
(byte)(Value / 256),
(byte)(Value % 256)
} :
Data;
ModbusUtils.ApplyByteOrder(data, 0, ReqPDU, 3, dataLength, ByteOrder, false);
}
// set response length
RespPduLen = ReqPDU.Length; // echo
}
}
/// <summary>
/// Performs a request in the ASCII mode.
/// </summary>
protected bool AsciiRequest(DataUnit dataUnit)
{
bool result = false;
// send request
log.WriteLine(dataUnit.ReqDescr);
Connection.WriteLine(dataUnit.ReqStr, out string logText);
log.WriteLine(logText);
// receive response
string line = Connection.ReadLine(Timeout, out logText);
log.WriteLine(logText);
int lineLen = line == null ? 0 : line.Length;
if (lineLen >= 3)
{
int aduLen = (lineLen - 1) / 2;
if (aduLen == dataUnit.RespAduLen && lineLen % 2 == 1)
{
// receive response ADU
byte[] aduBuf = new byte[aduLen];
bool parseOK = true;
for (int i = 0, j = 1; i < aduLen && parseOK; i++, j += 2)
{
try
{
aduBuf[i] = byte.Parse(line.Substring(j, 2), NumberStyles.HexNumber);
}
catch
{
log.WriteLine(ModbusPhrases.IncorrectSymbol);
parseOK = false;
}
}
if (parseOK)
{
if (aduBuf[aduLen - 1] == ModbusUtils.LRC(aduBuf, 0, aduLen - 1))
{
// decode response
if (dataUnit.DecodeRespPDU(aduBuf, 1, aduLen - 2, out string errMsg))
{
log.WriteLine(ModbusPhrases.OK);
result = true;
}
else
{
log.WriteLine(errMsg + "!");
}
}
else
{
log.WriteLine(ModbusPhrases.LrcError);
}
}
}
else
{
log.WriteLine(ModbusPhrases.IncorrectAduLength);
}
}
else
{
log.WriteLine(ModbusPhrases.CommErrorWithExclamation);
}
return(result);
}
/// <summary>
/// Performs a request in the PDU mode.
/// </summary>
protected bool RtuRequest(DataUnit dataUnit)
{
bool result = false;
// send request
log.WriteLine(dataUnit.ReqDescr);
Connection.Write(dataUnit.ReqADU, 0, dataUnit.ReqADU.Length, ProtocolFormat.Hex, out string logText);
log.WriteLine(logText);
// receive response
// partial read to calculate PDU length
const int FirstCount = 2;
int readCnt = Connection.Read(InBuf, 0, FirstCount, Timeout, ProtocolFormat.Hex, out logText);
log.WriteLine(logText);
if (readCnt != FirstCount)
{
log.WriteLine(ModbusPhrases.CommErrorWithExclamation);
}
else if (InBuf[0] != dataUnit.ReqADU[0]) // validate device address
{
log.WriteLine(ModbusPhrases.IncorrectDevAddr);
}
else if (!(InBuf[1] == dataUnit.FuncCode || InBuf[1] == dataUnit.ExcFuncCode)) // validate function code
{
log.WriteLine(ModbusPhrases.IncorrectPduFuncCode);
}
else
{
int pduLen;
int count;
if (InBuf[1] == dataUnit.FuncCode)
{
pduLen = dataUnit.RespPduLen;
count = dataUnit.RespAduLen - FirstCount;
}
else // exception received
{
pduLen = 2;
count = 3;
}
// read rest of response
readCnt = Connection.Read(InBuf, FirstCount, count, Timeout, ProtocolFormat.Hex, out logText);
log.WriteLine(logText);
if (readCnt != count)
{
log.WriteLine(ModbusPhrases.CommErrorWithExclamation);
}
else if (InBuf[pduLen + 1] + InBuf[pduLen + 2] * 256 != ModbusUtils.CRC16(InBuf, 0, pduLen + 1))
{
log.WriteLine(ModbusPhrases.CrcError);
}
else if (dataUnit.DecodeRespPDU(InBuf, 1, pduLen, out string errMsg))
{
log.WriteLine(ModbusPhrases.OK);
result = true;
}
else
{
log.WriteLine(errMsg + "!");
}
}
return(result);
}
