FieldTalk Modbus Master Library, Delphi Edition  Library version 2.12.0
TMbusSerialClientBase Class Reference

Base class for serial serial master protocols. More...

Public Member Functions

 TMbusSerialClientBase (TComponent aOwner)
 Constructs a TMbusSerialClientBase object and initialises its data.
 
 openProtocol ()
 Opens a serial Modbus protocol and the associated serial port with the port parameters configured via properties. More...
 
 openUseExistingConnection (integer cnxnHandle)
 Opens a serial Modbus protocol using an existing and open handle. More...
 
 enableRs485Mode (integer rtsDelay)
 Enables RS485 mode. More...
 
boolean isOpen ()
 Returns whether the protocol is open or not. More...
 
 closeProtocol ()
 Closes an open protocol including any associated communication resources (COM ports or sockets).
 
string getPackageVersion ()
 Returns the package version number. More...
 

Public Attributes

string portName
 Serial port identifier property (eg 'COM1') More...
 
longint baudRate
 Baud rate property in bps (typically 1200 - 115200, maximum value depends on UART hardware) More...
 
integer dataBits
 Data bits property. More...
 
integer stopBits
 Stop bits property. More...
 
integer parity
 Parity property. More...
 

Bit Access

Table 0:00000 (Coils) and Table 1:00000 (Input Status)

 readCoils (integer slaveAddr, integer startRef, boolean []bitArr)
 Modbus function 1 (01 hex), Read Coil Status/Read Coils. More...
 
 readInputDiscretes (integer slaveAddr, integer startRef, boolean []bitArr)
 Modbus function 2 (02 hex), Read Inputs Status/Read Input Discretes. More...
 
 writeCoil (integer slaveAddr, integer bitAddr, boolean bitVal)
 Modbus function 5 (05 hex), Force Single Coil/Write Coil. More...
 
 forceMultipleCoils (integer slaveAddr, integer startRef, boolean []bitArr)
 Modbus function 15 (0F hex), Force Multiple Coils. More...
 

16-bit Access

Table 4:00000 (Holding Registers) and Table 3:00000 (Input Registers)

 readMultipleRegisters (integer slaveAddr, integer startRef, word []regArr)
 Modbus function 3 (03 hex), Read Holding Registers/Read Multiple Registers. More...
 
 readInputRegisters (integer slaveAddr, integer startRef, word []regArr)
 Modbus function 4 (04 hex), Read Input Registers. More...
 
 writeSingleRegister (integer slaveAddr, integer regAddr, word regVal)
 Modbus function 6 (06 hex), Preset Single Register/Write Single Register. More...
 
 writeMultipleRegisters (integer slaveAddr, integer startRef, word []regArr)
 Modbus function 16 (10 hex), Preset Multiple Registers/Write Multiple Registers. More...
 
 maskWriteRegister (integer slaveAddr, integer regAddr, word andMask, word orMask)
 Modbus function 22 (16 hex), Mask Write Register. More...
 
 readWriteRegisters (integer slaveAddr, integer readRef, word []readArr, integer writeRef, word []writeArr)
 Modbus function 23 (17 hex), Read/Write Registers. More...
 

32-bit Access

Table 4:00000 (Holding Registers) and Table 3:00000 (Input Registers)

 readMultipleLongInts (integer slaveAddr, integer startRef, integer []int32Arr)
 Modbus function 3 (03 hex) for 32-bit long int data types, Read Holding Registers/Read Multiple Registers as long int data. More...
 
 readInputLongInts (integer slaveAddr, integer startRef, integer []int32Arr)
 Modbus function 4 (04 hex) for 32-bit long int data types, Read Input Registers as long int data. More...
 
 writeMultipleLongInts (integer slaveAddr, integer startRef, integer []int32Arr)
 Modbus function 16 (10 hex) for 32-bit long int data types, Preset Multiple Registers/Write Multiple Registers with long int data. More...
 
 readMultipleFloats (integer slaveAddr, integer startRef, single []float32Arr)
 Modbus function 3 (03 hex) for 32-bit float data types, Read Holding Registers/Read Multiple Registers as float data. More...
 
 readInputFloats (integer slaveAddr, integer startRef, single []float32Arr)
 Modbus function 4 (04 hex) for 32-bit float data types, Read Input Registers as float data. More...
 
 writeMultipleFloats (integer slaveAddr, integer startRef, single []float32Arr)
 Modbus function 16 (10 hex) for 32-bit float data types, Preset Multiple Registers/Write Multiple Registers with float data. More...
 
 readMultipleMod10000 (integer slaveAddr, integer startRef, integer []int32Arr)
 Modbus function 3 (03 hex) for 32-bit modulo-10000 long int data types, Read Holding Registers/Read Multiple Registers as modulo-10000 long int data. More...
 
 readInputMod10000 (integer slaveAddr, integer startRef, integer []int32Arr)
 Modbus function 4 (04 hex) for 32-bit modulo-10000 long int data types, Read Input Registers as modulo-10000 long int data. More...
 
 writeMultipleMod10000 (integer slaveAddr, integer startRef, integer []int32Arr)
 Modbus function 16 (10 hex) for 32-bit modulo-10000 long int data types, Preset Multiple Registers/Write Multiple Registers with modulo-10000 long int data. More...
 

64-bit Access

Table 4:00000 (Holding Registers) and Table 3:00000 (Input Registers)

 readHoldingRegistersI64 (integer slaveAddr, integer startRef, int64 []int64Arr)
 Modbus function 3 for 64-bit integer data, Read Holding Registers as int64_t type. More...
 
 readInputRegistersI64 (integer slaveAddr, integer startRef, int64 []int64Arr)
 Modbus function 4 for 64-bit integer data, Read Holding Registers as int64_t type. More...
 
 writeMultipleRegistersI64 (integer slaveAddr, integer startRef, int64 []int64Arr)
 Modbus function 16 (10 Hex) for 64-bit integer data, Write Multiple Registers as int64_t type. More...
 
 readHoldingRegistersF64 (integer slaveAddr, integer startRef, double []doubleArr)
 Modbus function 3 for 64-bit floating point data, Read Input Registers as double type. More...
 
 readInputRegistersF64 (integer slaveAddr, integer startRef, double []doubleArr)
 Modbus function 4 for 64-bit floating point data, Read Input Registers as double type. More...
 
 writeMultipleRegistersF64 (integer slaveAddr, integer startRef, double []doubleArr)
 Modbus function 16 (10 Hex) for 64-bit floating point data, Write Multiple Registers as double type. More...
 

Diagnostics

 readExceptionStatus (integer slaveAddr, byte &statusByte)
 Modbus function 7 (07 hex), Read Exception Status. More...
 
 returnQueryData (integer slaveAddr, byte []queryArr, byte []echoArr)
 Modbus function code 8, sub-function 00, Return Query Data. More...
 
 restartCommunicationsOption (integer slaveAddr, boolean clearEventLog)
 Modbus function code 8, sub-function 01, Restart Communications Option. More...
 

Custom Function Codes

 customFunction (integer slaveAddr, integer functionCode, byte []requestArr, byte []responseArr, integer &responseLen)
 User Defined Function CodeThis method can be used to implement User Defined Function Codes. More...
 

Protocol Configuration

integer timeout
 Time-out port property. More...
 
integer pollDelay
 Poll delay property. More...
 
integer retryCnt
 Retry count property. More...
 
 setTimeout (const integer timeOut)
 Configures time-out. More...
 
integer getTimeout ()
 Returns the time-out value. More...
 
 setPollDelay (const integer pollDelay)
 Configures poll delay. More...
 
integer getPollDelay ()
 Returns the poll delay time. More...
 
 setRetryCnt (const integer retryCnt)
 Configures the automatic retry setting. More...
 
integer getRetryCnt ()
 Returns the automatic retry count. More...
 

Transmission Statistic Functions

cardinal getTotalCounter ()
 Returns how often a message transfer has been executed. More...
 
 resetTotalCounter ()
 Resets total message transfer counter.
 
cardinal getSuccessCounter ()
 Returns how often a message transfer was successful. More...
 
 resetSuccessCounter ()
 Resets successful message transfer counter.
 

Slave Configuration

 configureBigEndianInts ()
 Configures int data type functions to do a word swap. More...
 
 configureBigEndianInts (integer slaveAddr)
 Enables int data type functions to do a word swap on a per slave basis. More...
 
 configureSwappedFloats ()
 Configures float data type functions to do a word swap. More...
 
 configureSwappedFloats (integer slaveAddr)
 Enables float data type functions to do a word swap on a per slave basis. More...
 
 configureLittleEndianInts ()
 Configures int data type functions not to do a word swap. More...
 
 configureLittleEndianInts (integer slaveAddr)
 Disables word swapping for int data type functions on a per slave basis. More...
 
 configureIeeeFloats ()
 Configures float data type functions not to do a word swap. More...
 
 configureIeeeFloats (integer slaveAddr)
 Disables float data type functions to do a word swap on a per slave basis. More...
 
 configureStandard32BitMode ()
 Configures all slaves for Standard 32-bit Mode. More...
 
 configureStandard32BitMode (integer slaveAddr)
 Configures a slave for Standard 32-bit Register Mode. More...
 
 configureEnron32BitMode ()
 Configures all slaves for Daniel/ENRON 32-bit Mode. More...
 
 configureEnron32BitMode (integer slaveAddr)
 Configures all slaves for Daniel/ENRON 32-bit Mode. More...
 
 configureCountFromOne ()
 Configures the reference counting scheme to start with one for all slaves. More...
 
 configureCountFromOne (integer slaveAddr)
 Configures a slave's reference counting scheme to start with one. More...
 
 configureCountFromZero ()
 Configures the reference counting scheme to start with zero for all slaves. More...
 
 configureCountFromZero (integer slaveAddr)
 Configures a slave's reference counting scheme to start with zero. More...
 

Detailed Description

Base class for serial serial master protocols.

This base class realises the Modbus serial master protocols. It provides functions to open and to close serial port as well as data and control functions which can be used at any time after the protocol has been opened. The data and control functions are organized different conformance classes. For a more detailed description of the data and control functions see section Data and Control Functions for all Modbus Protocol Flavours.

It is possible to instantiate multiple instances for establishing multiple connections on different serial ports (They should be executed in separate threads).

See also
Data and Control Functions for all Modbus Protocol Flavours, Serial Protocols

Member Function Documentation

◆ openProtocol()

openProtocol ( )

Opens a serial Modbus protocol and the associated serial port with the port parameters configured via properties.

This function opens the serial port. After a port has been opened, data and control functions can be used.

Exceptions
EInOutErrorAn I/O error occurred
EOpenErrThe serial port does not exist
EPortAlreadyOpenPort is already used by somedbody else
EPortNoAccessNo permission to access serial
EIllegalArgumentErrorA parameter is invalid

◆ openUseExistingConnection()

openUseExistingConnection ( integer  cnxnHandle)

Opens a serial Modbus protocol using an existing and open handle.

Useful for using the protocol over a modem link.

Parameters
cnxnHandleWin32 API handle pointing to the existing and open connection.
Exceptions
EIllegalArgumentErrorA parameter is invalid

◆ enableRs485Mode()

enableRs485Mode ( integer  rtsDelay)

Enables RS485 mode.

In RS485 mode the RTS signal can be used to enable and disable the transmitter of a RS232/RS485 converter. The RTS signal is asserted before sending data. It is cleared after the transmit buffer has been emptied and in addition the specified delay time has elapsed. The delay time is necessary because even the transmit buffer is already empty, the UART's FIFO will still contain unsent characters.

Warning
The use of RTS controlled RS232/RS485 converters should be avoided if possible. It is difficult to determine the exact time when to switch off the transmitter with non real-time operating systems like Windows and Linux. If it is switched off to early characters might still sit in the FIFO or the transmit register of the UART and these characters will be lost. Hence the slave will not recognize the message. On the other hand if it is switched off too late then the slave's message is corrupted and the master will not recognize the message.
Remarks
The delay value is indicative only and not guaranteed to be maintained. How precise it is followed depends on the operating system used, it's scheduling priority and it's system timer resolution.
Note
A protocol must be closed in order to configure it.
Parameters
rtsDelayDelay time in ms (Range: 0 - 100000) which applies after the transmit buffer is empty. 0 disables this mode.
Exceptions
EIllegalStateErrorProtocol is already open
EIllegalArgumentErrorA parameter is out of range

◆ readCoils()

readCoils ( integer  slaveAddr,
integer  startRef,
boolean []  bitArr 
)
inherited

Modbus function 1 (01 hex), Read Coil Status/Read Coils.

Reads the contents of the discrete outputs (coils, 0:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
bitArrBuffer which will contain the data read. The length of the array determines how many coils are read (Range: 1-2000).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputDiscretes()

readInputDiscretes ( integer  slaveAddr,
integer  startRef,
boolean []  bitArr 
)
inherited

Modbus function 2 (02 hex), Read Inputs Status/Read Input Discretes.

Reads the contents of the discrete inputs (input status, 1:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
bitArrBuffer which will contain the data read. The length of the array determines how many inputs are read (Range: 1-2000).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeCoil()

writeCoil ( integer  slaveAddr,
integer  bitAddr,
boolean  bitVal 
)
inherited

Modbus function 5 (05 hex), Force Single Coil/Write Coil.

Sets a single discrete output variable (coil, 0:00000 table) to either ON or OFF.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
bitAddrCoil address (Range: 1 - 65536)
bitValtrue sets, false clears discrete output variable
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ forceMultipleCoils()

forceMultipleCoils ( integer  slaveAddr,
integer  startRef,
boolean []  bitArr 
)
inherited

Modbus function 15 (0F hex), Force Multiple Coils.

Writes binary values into a sequence of discrete outputs (coils, 0:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
bitArrBuffer which contains the data to be sent. The length of the array determines how many coils are written (Range: 1-1968).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ readMultipleRegisters()

readMultipleRegisters ( integer  slaveAddr,
integer  startRef,
word []  regArr 
)
inherited

Modbus function 3 (03 hex), Read Holding Registers/Read Multiple Registers.

Reads the contents of the output registers (holding registers, 4:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart register (Range: 1 - 65536)
regArrBuffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-125).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputRegisters()

readInputRegisters ( integer  slaveAddr,
integer  startRef,
word []  regArr 
)
inherited

Modbus function 4 (04 hex), Read Input Registers.

Read the contents of the input registers (3:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart register (Range: 1 - 65536)
regArrBuffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-125).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeSingleRegister()

writeSingleRegister ( integer  slaveAddr,
integer  regAddr,
word  regVal 
)
inherited

Modbus function 6 (06 hex), Preset Single Register/Write Single Register.

Writes a value into a single output register (holding register, 4:00000 reference).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
regAddrRegister address (Range: 1 - 65536)
regValData to be sent
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ writeMultipleRegisters()

writeMultipleRegisters ( integer  slaveAddr,
integer  startRef,
word []  regArr 
)
inherited

Modbus function 16 (10 hex), Preset Multiple Registers/Write Multiple Registers.

Writes values into a sequence of output registers (holding registers, 4:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
startRefStart register (Range: 1 - 65536)
regArrBuffer with the data to be sent.The length of the array determines how many registers are written (Range: 1-123).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ maskWriteRegister()

maskWriteRegister ( integer  slaveAddr,
integer  regAddr,
word  andMask,
word  orMask 
)
inherited

Modbus function 22 (16 hex), Mask Write Register.

Masks bits according to an AND & an OR mask into a single output register (holding register, 4:00000 reference). Masking is done as follows: result = (currentVal AND andMask) OR (orMask AND (NOT andMask))

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
regAddrRegister address (Range: 1 - 65536)
andMaskMask to be applied as a logic AND to the register
orMaskMask to be applied as a logic OR to the register
Note
No broadcast supported

◆ readWriteRegisters()

readWriteRegisters ( integer  slaveAddr,
integer  readRef,
word []  readArr,
integer  writeRef,
word []  writeArr 
)
inherited

Modbus function 23 (17 hex), Read/Write Registers.

Combines reading and writing of the output registers in one transaction (holding registers, 4:00000 table).

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
readRefStart registers for reading (Range: 1 - 65536)
readArrBuffer which will contain the data read. The length of the array determines how many registers are read (Range: 1-125).
writeRefStart registers for writing (Range: 1 - 65536)
writeArrBuffer with data to be sent. The length of the array determines how many registers are written (Range: 1-121).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readMultipleLongInts()

readMultipleLongInts ( integer  slaveAddr,
integer  startRef,
integer []  int32Arr 
)
inherited

Modbus function 3 (03 hex) for 32-bit long int data types, Read Holding Registers/Read Multiple Registers as long int data.

Reads the contents of pairs of consecutive output registers (holding registers, 4:00000 table) into 32-bit long int values.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a long int value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of int values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
int32ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputLongInts()

readInputLongInts ( integer  slaveAddr,
integer  startRef,
integer []  int32Arr 
)
inherited

Modbus function 4 (04 hex) for 32-bit long int data types, Read Input Registers as long int data.

Reads the contents of pairs of consecutive input registers (3:00000 table) into 32-bit long int values.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a long int value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of int values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
int32ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeMultipleLongInts()

writeMultipleLongInts ( integer  slaveAddr,
integer  startRef,
integer []  int32Arr 
)
inherited

Modbus function 16 (10 hex) for 32-bit long int data types, Preset Multiple Registers/Write Multiple Registers with long int data.

Writes long int values into pairs of output registers (holding registers, 4:00000 table).

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a long int value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of int values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
startRefStart reference (Range: 1 - 65536)
int32ArrBuffer with the data to be sent. The length of the array determines how many values are read (Range: 1-61).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ readMultipleFloats()

readMultipleFloats ( integer  slaveAddr,
integer  startRef,
single []  float32Arr 
)
inherited

Modbus function 3 (03 hex) for 32-bit float data types, Read Holding Registers/Read Multiple Registers as float data.

Reads the contents of pairs of consecutive output registers (holding registers, 4:00000 table) into float values.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a float value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of float values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
float32ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputFloats()

readInputFloats ( integer  slaveAddr,
integer  startRef,
single []  float32Arr 
)
inherited

Modbus function 4 (04 hex) for 32-bit float data types, Read Input Registers as float data.

Reads the contents of pairs of consecutive input registers (3:00000 table) into float values.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a float value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of float values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
float32ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeMultipleFloats()

writeMultipleFloats ( integer  slaveAddr,
integer  startRef,
single []  float32Arr 
)
inherited

Modbus function 16 (10 hex) for 32-bit float data types, Preset Multiple Registers/Write Multiple Registers with float data.

Writes float values into pairs of output registers (holding registers, 4:00000 table).

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a float value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of float values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
startRefStart reference (Range: 1 - 65536)
float32ArrBuffer with the data to be sent. The length of the array determines how many values are written (Range: 1-61).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ readMultipleMod10000()

readMultipleMod10000 ( integer  slaveAddr,
integer  startRef,
integer []  int32Arr 
)
inherited

Modbus function 3 (03 hex) for 32-bit modulo-10000 long int data types, Read Holding Registers/Read Multiple Registers as modulo-10000 long int data.

Reads the contents of pairs of consecutive output registers (holding registers, 4:00000 table) representing a modulo-10000 long int value into 32-bit int values and performs number format conversion.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a modulo-10000 value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of int values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
int32ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputMod10000()

readInputMod10000 ( integer  slaveAddr,
integer  startRef,
integer []  int32Arr 
)
inherited

Modbus function 4 (04 hex) for 32-bit modulo-10000 long int data types, Read Input Registers as modulo-10000 long int data.

Reads the contents of pairs of consecutive input registers (3:00000 table) representing a modulo-10000 long int value into 32-bit long int values and performs number format conversion.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because an modulo-10000 value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of int values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
int32ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeMultipleMod10000()

writeMultipleMod10000 ( integer  slaveAddr,
integer  startRef,
integer []  int32Arr 
)
inherited

Modbus function 16 (10 hex) for 32-bit modulo-10000 long int data types, Preset Multiple Registers/Write Multiple Registers with modulo-10000 long int data.

Writes long int values into pairs of output registers (holding registers, 4:00000 table) representing a modulo-10000 long int value and performs number format conversion.

Remarks
Modbus does not know about any other data type than discretes and 16-bit registers. Because a modulo-10000 value is of 32-bit length, it will be transferred as two consecutive 16-bit registers. This means that the amount of registers transferred with this function is twice the amount of int values passed to this function.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
startRefStart reference (Range: 1 - 65536)
int32ArrBuffer with the data to be sent. The length of the array determines how many values are written (Range: 1-61).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ readHoldingRegistersI64()

readHoldingRegistersI64 ( integer  slaveAddr,
integer  startRef,
int64 []  int64Arr 
)
inherited

Modbus function 3 for 64-bit integer data, Read Holding Registers as int64_t type.

Reads the contents of quartets of consecutive holding registers (4:00000 table) into 64-bit integer values.

Remarks
Depending on the 32-bit Mode setting, an int64_t will be transferred as four consecutive 16-bit registers (Standard) or as two 32-bit registers (Daniel/Enron).
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
int64ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-31).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputRegistersI64()

readInputRegistersI64 ( integer  slaveAddr,
integer  startRef,
int64 []  int64Arr 
)
inherited

Modbus function 4 for 64-bit integer data, Read Holding Registers as int64_t type.

Reads the contents of quartets of consecutive input registers (3:00000 table) into 64-bit integer values.

Remarks
Depending on the 32-bit Mode setting, an int64_t will be transferred as four consecutive 16-bit registers (Standard) or as two 32-bit registers (Daniel/Enron).
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
int64ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-31).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeMultipleRegistersI64()

writeMultipleRegistersI64 ( integer  slaveAddr,
integer  startRef,
int64 []  int64Arr 
)
inherited

Modbus function 16 (10 Hex) for 64-bit integer data, Write Multiple Registers as int64_t type.

Writes for 64-bit integer values into quartets of holding registers (4:00000 table).

Remarks
Depending on the 32-bit Mode setting, an int will be transferred as four consecutive 16-bit registers (Standard) or as two 32-bit registers (Daniel/Enron).
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
startRefStart reference (Range: 1 - 65536)
int64ArrBuffer with the data to be sent. The length of the array determines how many values are read (Range: 1-30).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ readHoldingRegistersF64()

readHoldingRegistersF64 ( integer  slaveAddr,
integer  startRef,
double []  doubleArr 
)
inherited

Modbus function 3 for 64-bit floating point data, Read Input Registers as double type.

Reads the contents of quartets of consecutive input registers (4:00000 table) into 64-bit floating point values.

Remarks
Depending on the 32-bit Mode setting, a double will be transferred as four consecutive 16-bit registers (Standard) or as two 32-bit registers (Daniel/Enron).
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
double64ArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-31).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ readInputRegistersF64()

readInputRegistersF64 ( integer  slaveAddr,
integer  startRef,
double []  doubleArr 
)
inherited

Modbus function 4 for 64-bit floating point data, Read Input Registers as double type.

Reads the contents of quartets of consecutive input registers (3:00000 table) into 64-bit floating point values.

Remarks
Depending on the 32-bit Mode setting, a double will be transferred as four consecutive 16-bit registers (Standard) or as two 32-bit registers (Daniel/Enron).
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
startRefStart reference (Range: 1 - 65536)
doubleArrBuffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-31).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ writeMultipleRegistersF64()

writeMultipleRegistersF64 ( integer  slaveAddr,
integer  startRef,
double []  doubleArr 
)
inherited

Modbus function 16 (10 Hex) for 64-bit floating point data, Write Multiple Registers as double type.

Writes for 64-bit floating point values into quartets of holding registers (4:00000 table).

Remarks
Depending on the 32-bit Mode setting, a double will be transferred as four consecutive 16-bit registers (Standard) or as two 32-bit registers (Daniel/Enron).
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 0 - 255)
startRefStart reference (Range: 1 - 65536)
double64ArrBuffer with the data to be sent. The length of the array determines how many values are written (Range: 1-30).
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
Broadcast supported for serial protocols

◆ readExceptionStatus()

readExceptionStatus ( integer  slaveAddr,
byte &  statusByte 
)
inherited

Modbus function 7 (07 hex), Read Exception Status.

Reads the eight exception status coils within the slave device.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
statusByteSlave status byte. The meaning of this status byte is slave specific and varies from device to device.
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ returnQueryData()

returnQueryData ( integer  slaveAddr,
byte []  queryArr,
byte []  echoArr 
)
inherited

Modbus function code 8, sub-function 00, Return Query Data.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
queryArrData to be sent
echoArrBuffer which will contain the data read. Array must be of the same size as queryArr.
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ restartCommunicationsOption()

restartCommunicationsOption ( integer  slaveAddr,
boolean  clearEventLog 
)
inherited

Modbus function code 8, sub-function 01, Restart Communications Option.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255)
clearEventLogFlag when set to one clears in addition the slave's communication even log.
Exceptions
EIllegalStateErrorPort or connection is closed
EInOutErrorAn I/O error occurred
EIllegalArgumentErrorA parameter is out of range
EBusProtocolExceptionA protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.
Note
No broadcast supported

◆ setTimeout()

setTimeout ( const integer  timeOut)
inherited

Configures time-out.

This function sets the operation or socket time-out to the specified value.

Remarks
The time-out value is indicative only and not guaranteed to be maintained. How precise it is followed depends on the operating system used, it's scheduling priority and it's system timer resolution.
Note
A protocol must be closed in order to configure it.
Parameters
timeOutTimeout value in ms (Range: 1 - 100000)
Exceptions
EIllegalStateErrorProtocol is already open
EIllegalArgumentErrorA parameter is out of range

◆ getTimeout()

integer getTimeout ( )
inherited

Returns the time-out value.

Remarks
The time-out value is indicative only and not guaranteed to be maintained. How precise it is followed depends on the operating system used, it's scheduling priority and it's system timer resolution.
Returns
Timeout value in ms

◆ setPollDelay()

setPollDelay ( const integer  pollDelay)
inherited

Configures poll delay.

This function sets the delay time which applies between two consecutive Modbus read/write. A value of 0 disables the poll delay.

Remarks
The delay value is indicative only and not guaranteed to be maintained. How precise it is followed depends on the operating system used, it's scheduling priority and it's system timer resolution.
Note
A protocol must be closed in order to configure it.
Parameters
pollDelayDelay time in ms (Range: 0 - 100000), 0 disables poll delay
Exceptions
EIllegalStateErrorProtocol is already open
EIllegalArgumentErrorA parameter is out of range

◆ getPollDelay()

integer getPollDelay ( )
inherited

Returns the poll delay time.

Returns
Delay time in ms, 0 if poll delay is switched off

◆ setRetryCnt()

setRetryCnt ( const integer  retryCnt)
inherited

Configures the automatic retry setting.

A value of 0 disables any automatic retries.

Note
A protocol must be closed in order to configure it.
Parameters
retryCntRetry count (Range: 0 - 10), 0 disables retries
Exceptions
EIllegalStateErrorProtocol is already open
EIllegalArgumentErrorA parameter is out of range

◆ getRetryCnt()

integer getRetryCnt ( )
inherited

Returns the automatic retry count.

Returns
Retry count

◆ getTotalCounter()

cardinal getTotalCounter ( )
inherited

Returns how often a message transfer has been executed.

Returns
Counter value

◆ getSuccessCounter()

cardinal getSuccessCounter ( )
inherited

Returns how often a message transfer was successful.

Returns
Counter value

◆ configureBigEndianInts() [1/2]

configureBigEndianInts ( )
inherited

Configures int data type functions to do a word swap.

Modbus is using little-endian word order for 32-bit values. The data transfer functions operating upon 32-bit int data types can be configured to do a word swap which enables them to read 32-bit data correctly from a big-endian machine.

◆ configureBigEndianInts() [2/2]

configureBigEndianInts ( integer  slaveAddr)
inherited

Enables int data type functions to do a word swap on a per slave basis.

Modbus is using little-endian word order for 32-bit values. The data transfer functions operating upon 32-bit int data types can be configured to do a word swap which enables them to read 32-bit data correctly from a big-endian machine.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureSwappedFloats() [1/2]

configureSwappedFloats ( )
inherited

Configures float data type functions to do a word swap.

The data functions operating upon 32-bit float data types can be configured to do a word swap.

Note
Most platforms store floats in IEEE 754 little-endian order which does not need a word swap.

◆ configureSwappedFloats() [2/2]

configureSwappedFloats ( integer  slaveAddr)
inherited

Enables float data type functions to do a word swap on a per slave basis.

The data functions operating upon 32-bit float data types can be configured to do a word swap.

Note
Most platforms store floats in IEEE 754 little-endian order which does not need a word swap.
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureLittleEndianInts() [1/2]

configureLittleEndianInts ( )
inherited

Configures int data type functions not to do a word swap.

This is the default.

◆ configureLittleEndianInts() [2/2]

configureLittleEndianInts ( integer  slaveAddr)
inherited

Disables word swapping for int data type functions on a per slave basis.

Modbus is using little-endian word order for 32-bit values. This setting assumes that the slave also serves 32-bit data in little little-endian word order.

Remarks
This is the default mode
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureIeeeFloats() [1/2]

configureIeeeFloats ( )
inherited

Configures float data type functions not to do a word swap.

This is the default.

◆ configureIeeeFloats() [2/2]

configureIeeeFloats ( integer  slaveAddr)
inherited

Disables float data type functions to do a word swap on a per slave basis.

Modbus is using little-endian word order for 32-bit values. This setting assumes that the slave also serves 32-bit floats in little little-endian word order which is the most common case.

Remarks
This is the default mode
Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureStandard32BitMode() [1/2]

configureStandard32BitMode ( )
inherited

Configures all slaves for Standard 32-bit Mode.

In Standard 32-bit Register Mode a 32-bit value is transmitted as two consecutive 16-bit Modbus registers.

Remarks
This is the default mode

◆ configureStandard32BitMode() [2/2]

configureStandard32BitMode ( integer  slaveAddr)
inherited

Configures a slave for Standard 32-bit Register Mode.

In Standard 32-bit Register Mode a 32-bit value is transmitted as two consecutive 16-bit Modbus registers.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureEnron32BitMode() [1/2]

configureEnron32BitMode ( )
inherited

Configures all slaves for Daniel/ENRON 32-bit Mode.

Some Modbus flavours like the Daniel/Enron protocol represent a 32-bit value using one 32-bit Modbus register instead of two 16-bit registers.

◆ configureEnron32BitMode() [2/2]

configureEnron32BitMode ( integer  slaveAddr)
inherited

Configures all slaves for Daniel/ENRON 32-bit Mode.

Some Modbus flavours like the Daniel/Enron protocol represent a 32-bit value using one 32-bit Modbus register instead of two 16-bit registers.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureCountFromOne() [1/2]

configureCountFromOne ( )
inherited

Configures the reference counting scheme to start with one for all slaves.

This renders the reference range to be 1 to 65536 and register #0 is an illegal register.

Remarks
This is the default mode

◆ configureCountFromOne() [2/2]

configureCountFromOne ( integer  slaveAddr)
inherited

Configures a slave's reference counting scheme to start with one.

This renders the reference range to be 1 to 65536 and register #0 is an illegal register.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Remarks
This is the default mode
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ configureCountFromZero() [1/2]

configureCountFromZero ( )
inherited

Configures the reference counting scheme to start with zero for all slaves.

This renders the valid reference range to be 0 to 65535.

This renders the first register to be #0 for all slaves.

◆ configureCountFromZero() [2/2]

configureCountFromZero ( integer  slaveAddr)
inherited

Configures a slave's reference counting scheme to start with zero.

This is also known as PDU addressing.

This renders the valid reference range to be 0 to 65535.

Parameters
slaveAddrModbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.
Exceptions
EIllegalArgumentErrorA parameter is out of range

◆ isOpen()

boolean isOpen ( )
inherited

Returns whether the protocol is open or not.

Return values
true= open
false= closed

◆ getPackageVersion()

class string getPackageVersion ( )
inherited

Returns the package version number.

Returns
Package version string

Member Data Documentation

◆ portName

string portName

Serial port identifier property (eg 'COM1')

Note
A protocol must be closed in order to configure it.
See also
fPortName For reading
fPortName For writing

◆ baudRate

longint baudRate

Baud rate property in bps (typically 1200 - 115200, maximum value depends on UART hardware)

Note
A protocol must be closed in order to configure it.
See also
fBaudRate For reading
fBaudRate For writing

◆ dataBits

integer dataBits

Data bits property.

SER_DATABITS_7: 7 data bits (ASCII protocol only), SER_DATABITS_8: 8 data bits

Note
A protocol must be closed in order to configure it.
See also
fDataBits For reading
fDataBits For writing

◆ stopBits

integer stopBits

Stop bits property.

SER_STOPBITS_1: 1 stop bit, SER_STOPBITS_2: 2 stop bits

Note
The Modbus standard requires two stop bits if no parity is chosen. This library is not enforcing this but it is a recommended configuration.
A protocol must be closed in order to configure it.
See also
fStopBits For reading
fStopBits For writing

◆ parity

integer parity

Parity property.

SER_PARITY_NONE: no parity, SER_PARITY_ODD: odd parity, SER_PARITY_EVEN: even parity

Note
The Modbus standard requires two stop bits if no parity is chosen. This library is not enforcing this but it is a recommended configuration.
A protocol must be closed in order to configure it.
See also
fParity For reading
fParity For writing

◆ timeout

integer timeout
inherited

Time-out port property.

Note
A protocol must be closed in order to configure it.
See also
getTimeout For reading
setTimeout For writing

◆ pollDelay

integer pollDelay
inherited

Poll delay property.

Delay between two Modbus read/writes in ms

Note
A protocol must be closed in order to configure it.
See also
getPollDelay For reading
setPollDelay For writing

◆ retryCnt

integer retryCnt
inherited

Retry count property.

Note
A protocol must be closed in order to configure it.
See also
getRetryCnt For reading
setRetryCnt For writing