Modbus RTU Master Protocol class. More...

Inheritance diagram for TMbusRtuMasterProtocol:

Public Member Functions
	TMbusRtuMasterProtocol (TComponent aOwner)
	Constructs a TMbusRtuMasterProtocol object and initialises its data.
	openProtocol ()
	Opens a serial Modbus protocol and the associated serial port with the port parameters configured via properties.
	openUseExistingConnection (integer cnxnHandle)
	Opens a serial Modbus protocol using an existing and open handle.
	enableRs485Mode (integer rtsDelay)
	Enables RS485 mode.
boolean	isOpen ()
	Returns whether the protocol is open or not.
	closeProtocol ()
	Closes an open protocol including any associated communication resources (COM ports or sockets).
string	getPackageVersion ()
	Returns the package version number.
Public Attributes
string	portName
	Serial port identifier property (eg 'COM1').
longint	baudRate
	Baud rate property in bps (typically 1200 - 115200, maximum value depends on UART hardware).
integer	dataBits
	Data bits property.
integer	stopBits
	Stop bits property.
integer	parity
	Parity property.
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.
	readInputDiscretes (integer slaveAddr, integer startRef, boolean[]bitArr)
	Modbus function 2 (02 hex), Read Inputs Status/Read Input Discretes.
	writeCoil (integer slaveAddr, integer bitAddr, boolean bitVal)
	Modbus function 5 (05 hex), Force Single Coil/Write Coil.
	forceMultipleCoils (integer slaveAddr, integer startRef, boolean[]bitArr)
	Modbus function 15 (0F hex), Force Multiple Coils.
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.
	readInputRegisters (integer slaveAddr, integer startRef, word[]regArr)
	Modbus function 4 (04 hex), Read Input Registers.
	writeSingleRegister (integer slaveAddr, integer regAddr, word regVal)
	Modbus function 6 (06 hex), Preset Single Register/Write Single Register.
	writeMultipleRegisters (integer slaveAddr, integer startRef, word[]regArr)
	Modbus function 16 (10 hex), Preset Multiple Registers/Write Multiple Registers.
	maskWriteRegister (integer slaveAddr, integer regAddr, word andMask, word orMask)
	Modbus function 22 (16 hex), Mask Write Register.
	readWriteRegisters (integer slaveAddr, integer readRef, word[]readArr, integer writeRef, word[]writeArr)
	Modbus function 23 (17 hex), Read/Write Registers.
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.
	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.
	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.
	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.
	readInputFloats (integer slaveAddr, integer startRef, single[]float32Arr)
	Modbus function 4 (04 hex) for 32-bit float data types, Read Input Registers as float data.
	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.
	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.
	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.
	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.
Diagnostics

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

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

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

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

Detailed Description

Modbus RTU Master Protocol class.

This class realizes the Modbus RTU master protocol. 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 of this class 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; TMbusMasterFunctions, TMbusSerialMasterProtocol, TMbusAsciiMasterProtocol, TMbusTcpMasterProtocol, TMbusRtuOverTcpMasterProtocol

Constructor & Destructor Documentation

TMbusRtuMasterProtocol ( TComponent aOwner )

Constructs a TMbusRtuMasterProtocol object and initialises its data.

Exceptions:

EOutOfResources

Creation of class failed

Member Function Documentation

openProtocol ( ) [inherited]

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:

	EInOutError	An I/O error occurred
	EOpenErr	The serial port does not exist
	EPortAlreadyOpen	Port is already used by somedbody else
	EPortNoAccess	No permission to access serial
	EIllegalArgumentError	A parameter is invalid

openUseExistingConnection ( integer cnxnHandle ) [inherited]

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

Useful for using the protocol over a modem link.

Parameters:

cnxnHandle

Win32 API handle pointing to the existing and open connection.

Exceptions:

EIllegalArgumentError

A parameter is invalid

enableRs485Mode ( integer rtsDelay ) [inherited]

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:

rtsDelay

Delay time in ms (Range: 0 - 100000) which applies after the transmit buffer is empty. 0 disables this mode.

Exceptions:

	EIllegalStateError	Protocol is already open
	EIllegalArgumentError	A parameter is out of range

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	bitArr	Buffer which will contain the data read. The length of the array determines how many coils are read (Range: 1-2000).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	bitArr	Buffer which will contain the data read. The length of the array determines how many inputs are read (Range: 1-2000).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 0 - 255)
	bitAddr	Coil address (Range: 1 - 65536)
	bitVal	true sets, false clears discrete output variable

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	bitArr	Buffer which contains the data to be sent. The length of the array determines how many coils are written (Range: 1-1968).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start register (Range: 1 - 65536)
	regArr	Buffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-125).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start register (Range: 1 - 65536)
	regArr	Buffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-125).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 0 - 255)
	regAddr	Register address (Range: 1 - 65536)
	regVal	Data to be sent

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 0 - 255)
	startRef	Start register (Range: 1 - 65536)
	regArr	Buffer with the data to be sent.The length of the array determines how many registers are written (Range: 1-123).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	regAddr	Register address (Range: 1 - 65536)
	andMask	Mask to be applied as a logic AND to the register
	orMask	Mask to be applied as a logic OR to the register

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	readRef	Start registers for reading (Range: 1 - 65536)
	readArr	Buffer which will contain the data read. The length of the array determines how many registers are read (Range: 1-125).
	writeRef	Start registers for writing (Range: 1 - 65536)
	writeArr	Buffer with data to be sent. The length of the array determines how many registers are written (Range: 1-121).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	int32Arr	Buffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	int32Arr	Buffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 0 - 255)
	startRef	Start reference (Range: 1 - 65536)
	int32Arr	Buffer with the data to be sent. The length of the array determines how many values are read (Range: 1-61).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	float32Arr	Buffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	float32Arr	Buffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 0 - 255)
	startRef	Start reference (Range: 1 - 65536)
	float32Arr	Buffer with the data to be sent. The length of the array determines how many values are written (Range: 1-61).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	int32Arr	Buffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	startRef	Start reference (Range: 1 - 65536)
	int32Arr	Buffer which will be filled with the data read. The length of the array determines how many values are read (Range: 1-62).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 0 - 255)
	startRef	Start reference (Range: 1 - 65536)
	int32Arr	Buffer with the data to be sent. The length of the array determines how many values are written (Range: 1-61).

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: Broadcast supported for serial protocols

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:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	statusByte	Slave status byte. The meaning of this status byte is slave specific and varies from device to device.

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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

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

Parameters:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	queryArr	Data to be sent
	echoArr	Buffer which will contain the data read. Array must be of the same size as queryArr.

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

restartCommunicationsOption	(	integer	slaveAddr,
		boolean	clearEventLog
	)			`[inherited]`

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

Parameters:

	slaveAddr	Modbus address of slave device or unit identifier (Range: 1 - 255)
	clearEventLog	Flag when set to one clears in addition the slave's communication even log.

Exceptions:

	EIllegalStateError	Port or connection is closed
	EInOutError	An I/O error occurred
	EIllegalArgumentError	A parameter is out of range
	EBusProtocolException	A protocol failure occurred. See descendants of EBusProtocolException for a more detailed failure list.

Note:: No broadcast supported

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:

timeOut

Timeout value in ms (Range: 1 - 100000)

Exceptions:

	EIllegalStateError	Protocol is already open
	EIllegalArgumentError	A parameter is out of range

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 ( 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:

pollDelay

Delay time in ms (Range: 0 - 100000), 0 disables poll delay

Exceptions:

	EIllegalStateError	Protocol is already open
	EIllegalArgumentError	A parameter is out of range

integer getPollDelay ( ) [inherited]

Returns the poll delay time.

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

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:

retryCnt

Retry count (Range: 0 - 10), 0 disables retries

Exceptions:

	EIllegalStateError	Protocol is already open
	EIllegalArgumentError	A parameter is out of range

integer getRetryCnt ( ) [inherited]

Returns the automatic retry count.

Returns:: Retry count

cardinal getTotalCounter ( ) [inherited]

Returns how often a message transfer has been executed.

Returns:: Counter value

cardinal getSuccessCounter ( ) [inherited]

Returns how often a message transfer was successful.

Returns:: Counter value

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 ( 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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

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 ( 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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

configureLittleEndianInts ( ) [inherited]

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

This is the default.

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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

configureIeeeFloats ( ) [inherited]

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

This is the default.

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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

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 ( 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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

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 ( 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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

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 ( 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:

slaveAddr

Modbus 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:

EIllegalArgumentError

A parameter is out of range

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 ( 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:

slaveAddr

Modbus address of slave device or unit identifier (Range: 1 - 255). A value of zero configures the behaviour for broadcasting.

Exceptions:

EIllegalArgumentError

A parameter is out of range

boolean isOpen ( ) [inherited]

Returns whether the protocol is open or not.

Return values:

	true	= open
	false	= closed

class string getPackageVersion ( ) [inherited]

Returns the package version number.

Returns:: Package version string

Member Data Documentation

string portName [inherited]

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

longint baudRate [inherited]

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

integer dataBits [inherited]

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

integer stopBits [inherited]

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

integer parity [inherited]

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

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

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

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

FieldTalk Modbus Master Library, Delphi Edition
Library version 2.6.2

TMbusRtuMasterProtocol Class Reference [Serial Protocols]

Public Member Functions

Public Attributes

Bit Access

16-bit Access

32-bit Access

Diagnostics

Custom Function Codes

Protocol Configuration

Transmission Statistic Functions

Slave Configuration

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

TMbusRtuMasterProtocol Class Reference
[Serial Protocols]