Modbus Buffer ManagementModbus Buffer ManagementFunctions void Modbus::buildException (uint8_t u8exception)This method builds an exception message. uint16_t Modbus::calcCRC (uint8_t u8length)This method calculates CRC. uint16_t Modbus::getErrCnt ()error counter uint16_t Modbus::getInCnt ()number of incoming messages uint8_t Modbus::getLastError ()get last error message uint16_t Modbus::getOutCnt ()number of outcoming messages int8_t Modbus::getRxBuffer ()This method moves Serial buffer data to the Modbus au8Buffer. uint8_t Modbus::getState ()void Modbus::sendTxBuffer ()This method transmits au8Buffer to Serial line. Only if u8txenpin != 0, there is a flow handling in order to keep the RS485 transceiver in output state as long as the message is being sent. This is done with UCSRxA register. The CRC is appended to the buffer before starting to send it. uint8_t Modbus::validateAnswer ()This method validates master incoming messages. uint8_t Modbus::validateRequest ()This method validates slave incoming messages. Detailed DescriptionFunction DocumentationbuildException()buildExceptionModbus Buffer ManagementModbus Buffer ManagementbuildExceptionvoid Modbus::buildException (uint8_t u8exception)[private]This method builds an exception message.
Definition at line 1244 of file ModbusRtu.h.01245 {
01246 uint8_t u8func = au8Buffer[FUNC]; // get the original FUNC code
01247
01248 au8Buffer[ID] = u8id;
01249 au8Buffer[FUNC] = u8func + 0x80;
01250 au8Buffer[2] = u8exception;
01251 u8BufferSize = EXCEPTION_SIZE;
01252 }
calcCRC()calcCRCModbus Buffer ManagementModbus Buffer ManagementcalcCRCuint16_t Modbus::calcCRC (uint8_t u8length)[private]This method calculates CRC. Returnsuint16_t calculated CRC value for the message
Definition at line 1096 of file ModbusRtu.h.01097 {
01098 unsignedint temp, temp2, flag;
01099 temp = 0xFFFF;
01100 for (unsignedchar i = 0; i < u8length; i++)
01101 {
01102 temp = temp ^ au8Buffer[i];
01103 // Serial.println(au8Buffer[i], DEC);
01104 for (unsignedchar j = 1; j <= 8; j++)
01105 {
01106 flag = temp & 0x0001;
01107 temp >>= 1;
01108 if (flag)
01109 temp ^= 0xA001;
01110 }
01111 }
01112 // Reverse byte order.
01113 temp2 = temp >> 8;
01114 temp = (temp << 8) | temp2;
01115 temp &= 0xFFFF;
01116 // the returned value is already swapped
01117 // crcLo byte is first & crcHi byte is last
01118 return temp;
01119 }
getErrCnt()getErrCntModbus Buffer ManagementModbus Buffer ManagementgetErrCntuint16_t Modbus::getErrCnt ( )error counter Get errors counter value This can be useful to diagnose communication.Returnserrors counter
Definition at line 545 of file ModbusRtu.h.00546 {
00547 return u16errCnt;
00548 }
getInCnt()getInCntModbus Buffer ManagementModbus Buffer ManagementgetInCntuint16_t Modbus::getInCnt ( )number of incoming messages Get input messages counter value This can be useful to diagnose communication.Returnsinput messages counter
Definition at line 519 of file ModbusRtu.h.00520 {
00521 return u16InCnt;
00522 }
getLastError()getLastErrorModbus Buffer ManagementModbus Buffer ManagementgetLastErroruint8_t Modbus::getLastError ( )get last error message Get the last error in the protocol processor@returnreturn NO_REPLY = 255 Time-out ReturnsEXC_FUNC_CODE = 1 Function code not available EXC_ADDR_RANGE = 2 Address beyond available space for Modbus registers EXC_REGS_QUANT = 3 Coils or registers number beyond the available space
Definition at line 575 of file ModbusRtu.h.00576 {
00577 return u8lastError;
00578 }
getOutCnt()getOutCntModbus Buffer ManagementModbus Buffer ManagementgetOutCntuint16_t Modbus::getOutCnt ( )number of outcoming messages Get transmitted messages counter value This can be useful to diagnose communication.Returnstransmitted messages counter
Definition at line 532 of file ModbusRtu.h.00533 {
00534 return u16OutCnt;
00535 }
getRxBuffer()getRxBufferModbus Buffer ManagementModbus Buffer ManagementgetRxBufferint8_t Modbus::getRxBuffer ( )[private]This method moves Serial buffer data to the Modbus au8Buffer. Returnsbuffer size if OK, ERR_BUFF_OVERFLOW if u8BufferSize >= MAX_BUFFER
Definition at line 905 of file ModbusRtu.h.00906 {
00907 boolean bBuffOverflow = false;
00908
00909 if (u8txenpin > 1)
00910 {
00911 RS485_CLEAR_DE;
00912 RS485_CLEAR_RE;
00913 // digitalWrite( u8txenpin, LOW );
00914 }
00915
00916 u8BufferSize = 0;
00917 if (u8serno < 4)
00918 while (port->available())
00919 {
00920 au8Buffer[u8BufferSize] = port->read();
00921 rxBuffer[u8BufferSize] = au8Buffer[u8BufferSize];
00922 u8BufferSize++;
00923
00924 if (u8BufferSize >= MAX_BUFFER)
00925 bBuffOverflow = true;
00926 }
00927 else
00928 while (softPort->available())
00929 {
00930 au8Buffer[u8BufferSize] = softPort->read();
00931 u8BufferSize++;
00932
00933 if (u8BufferSize >= MAX_BUFFER)
00934 bBuffOverflow = true;
00935 }
00936 u16InCnt++;
00937
00938 if (bBuffOverflow)
00939 {
00940 Log.verboseln("buffer overflow: %d", u8BufferSize);
00941 u16errCnt++;
00942 return ERR_BUFF_OVERFLOW;
00943 }
00944 //Log.verboseln("getRX-Buffer : %d",u8BufferSize);
00945 //printHex(rxBuffer, u8BufferSize);
00946 rxSize = u8BufferSize;
00947 return u8BufferSize;
00948 }
getState()getStateModbus Buffer ManagementModbus Buffer ManagementgetStateuint8_t Modbus::getState ( )Get modbus master stateReturns= 0 IDLE, = 1 WAITING FOR ANSWER
Definition at line 561 of file ModbusRtu.h.00562 {
00563 return u8state;
00564 }
sendTxBuffer()sendTxBufferModbus Buffer ManagementModbus Buffer ManagementsendTxBuffervoid Modbus::sendTxBuffer ( )[private]This method transmits au8Buffer to Serial line. Only if u8txenpin != 0, there is a flow handling in order to keep the RS485 transceiver in output state as long as the message is being sent. This is done with UCSRxA register. The CRC is appended to the buffer before starting to send it.
Parameters
nothing
Returnsnothing
Definition at line 962 of file ModbusRtu.h.00963 {
00964 uint8_t i = 0;
00965
00966 // append CRC to message
00967 uint16_t u16crc = calcCRC(u8BufferSize);
00968 /*
00969 Serial.print("---- calc CRC : HEX : ");
00970 Serial.print(u16crc, DEC);
00971 Serial.print(" - HEX : ");
00972 Serial.print(u16crc, HEX);
00973 Serial.print(" - ");
00974 Serial.print(u8BufferSize);
00975 Serial.print("\n");
00976 */
00977
00978 au8Buffer[u8BufferSize] = u16crc >> 8;
00979 u8BufferSize++;
00980 au8Buffer[u8BufferSize] = u16crc & 0x00ff;
00981 u8BufferSize++;
00982
00983 if (debugSend)
00984 {
00985 Serial.print("Send Hex : \t");
00986 for (int i = 0; i < 8; i++)
00987 {
00988 Serial.print(au8Buffer[i], HEX);
00989 Serial.print(" : ");
00990 }
00991 Serial.println("--------------- \n");
00992 }
00993
00994 // set RS485 transceiver to transmit mode
00995 if (u8txenpin > 1)
00996 {
00997 switch (u8serno)
00998 {
00999 #if defined(UBRR1H)
01000 case 1:
01001 UCSR1A = UCSR1A | (1 << TXC1);
01002 break;
01003 #endif
01004
01005 #if defined(UBRR2H)
01006 case 2:
01007 UCSR2A = UCSR2A | (1 << TXC2);
01008 break;
01009 #endif
01010
01011 #if defined(UBRR3H)
01012 case 3:
01013 UCSR3A = UCSR3A | (1 << TXC3);
01014 break;
01015 #endif
01016 case 0:
01017 default:
01018 UCSR0A = UCSR0A | (1 << TXC0);
01019 break;
01020 }
01021 RS485_SET_DE;
01022 RS485_SET_RE;
01023 // digitalWrite( u8txenpin, HIGH );
01024 }
01025
01026 // transfer buffer to serial line
01027 if (u8serno < 4)
01028 {
01029 port->write(au8Buffer, u8BufferSize);
01030 }
01031 else
01032 {
01033 softPort->write(au8Buffer, u8BufferSize);
01034 }
01035 // keep RS485 transceiver in transmit mode as long as sending
01036 if (u8txenpin > 1)
01037 {
01038 switch (u8serno)
01039 {
01040 #if defined(UBRR1H)
01041 case 1:
01042 while (!(UCSR1A & (1 << TXC1)))
01043 ;
01044 break;
01045 #endif
01046
01047 #if defined(UBRR2H)
01048 case 2:
01049 while (!(UCSR2A & (1 << TXC2)))
01050 ;
01051 break;
01052 #endif
01053
01054 #if defined(UBRR3H)
01055 case 3:
01056 while (!(UCSR3A & (1 << TXC3)))
01057 ;
01058 break;
01059 #endif
01060 case 0:
01061 default:
01062 while (!(UCSR0A & (1 << TXC0)))
01063 ;
01064 break;
01065 }
01066 // return RS485 transceiver to receive mode
01067 RS485_CLEAR_DE;
01068 RS485_CLEAR_RE;
01069 // digitalWrite( u8txenpin, LOW );
01070 }
01071 if (u8serno < 4)
01072 while (port->read() >= 0)
01073 ;
01074 else
01075 while (softPort->read() >= 0)
01076 ;
01077
01078 u8BufferSize = 0;
01079
01080 // set time-out for master
01081 u32timeOut = millis() + (unsigned long)u16timeOut;
01082
01083 // increase message counter
01084 u16OutCnt++;
01085
01086 currentQuery->flags = QUERY_STATE::SENT;
01087 }
validateAnswer()validateAnswerModbus Buffer ManagementModbus Buffer ManagementvalidateAnsweruint8_t Modbus::validateAnswer ( )[private]This method validates master incoming messages. Returns0 if OK, EXCEPTION if anything fails
Definition at line 1201 of file ModbusRtu.h.01202 {
01203 // check message crc vs calculated crc
01204 uint16_t u16MsgCRC =
01205 ((au8Buffer[u8BufferSize - 2] << 8) | au8Buffer[u8BufferSize - 1]); // combine the crc Low & High bytes
01206 if (calcCRC(u8BufferSize - 2) != u16MsgCRC)
01207 {
01208 u16errCnt++;
01209 return NO_REPLY;
01210 }
01211
01212 // check exception
01213 if ((au8Buffer[FUNC] & 0x80) != 0)
01214 {
01215 u16errCnt++;
01216 return ERR_EXCEPTION;
01217 }
01218
01219 // check fct code
01220 boolean isSupported = false;
01221 for (uint8_t i = 0; i < sizeof(fctsupported); i++)
01222 {
01223 if (fctsupported[i] == au8Buffer[FUNC])
01224 {
01225 isSupported = 1;
01226 break;
01227 }
01228 }
01229 if (!isSupported)
01230 {
01231 u16errCnt++;
01232 return EXC_FUNC_CODE;
01233 }
01234
01235 return 0; // OK, no exception code thrown
01236 }
validateRequest()validateRequestModbus Buffer ManagementModbus Buffer ManagementvalidateRequestuint8_t Modbus::validateRequest ( )[private]This method validates slave incoming messages. Returns0 if OK, EXCEPTION if anything fails
Definition at line 1128 of file ModbusRtu.h.01129 {
01130 // check message crc vs calculated crc
01131 uint16_t u16MsgCRC =
01132 ((au8Buffer[u8BufferSize - 2] << 8) | au8Buffer[u8BufferSize - 1]); // combine the crc Low & High bytes
01133 if (calcCRC(u8BufferSize - 2) != u16MsgCRC)
01134 {
01135 u16errCnt++;
01136 return NO_REPLY;
01137 }
01138
01139 // check fct code
01140 boolean isSupported = false;
01141 for (uint8_t i = 0; i < sizeof(fctsupported); i++)
01142 {
01143 if (fctsupported[i] == au8Buffer[FUNC])
01144 {
01145 isSupported = 1;
01146 break;
01147 }
01148 }
01149 if (!isSupported)
01150 {
01151 u16errCnt++;
01152 return EXC_FUNC_CODE;
01153 }
01154
01155 // check start address & nb range
01156 uint16_t u16regs = 0;
01157 uint8_t u8regs;
01158 switch (au8Buffer[FUNC])
01159 {
01160 case MB_FC_READ_COILS:
01161 case MB_FC_READ_DISCRETE_INPUT:
01162 case MB_FC_WRITE_MULTIPLE_COILS:
01163 u16regs = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]) / 16;
01164 u16regs += word(au8Buffer[NB_HI], au8Buffer[NB_LO]) / 16;
01165 u8regs = (uint8_t)u16regs;
01166 if (u8regs > u8regsize)
01167 return EXC_ADDR_RANGE;
01168 break;
01169 case MB_FC_WRITE_COIL:
01170 u16regs = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]) / 16;
01171 u8regs = (uint8_t)u16regs;
01172 if (u8regs > u8regsize)
01173 return EXC_ADDR_RANGE;
01174 break;
01175 case MB_FC_WRITE_REGISTER:
01176 u16regs = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]);
01177 u8regs = (uint8_t)u16regs;
01178 if (u8regs > u8regsize)
01179 return EXC_ADDR_RANGE;
01180 break;
01181 case MB_FC_READ_REGISTERS:
01182 case MB_FC_READ_INPUT_REGISTER:
01183 case MB_FC_WRITE_MULTIPLE_REGISTERS:
01184 u16regs = word(au8Buffer[ADD_HI], au8Buffer[ADD_LO]);
01185 u16regs += word(au8Buffer[NB_HI], au8Buffer[NB_LO]);
01186 u8regs = (uint8_t)u16regs;
01187 if (u8regs > u8regsize)
01188 return EXC_ADDR_RANGE;
01189 break;
01190 }
01191 return 0; // OK, no exception code thrown
01192 }