This protocol stack implements the most commonly used Modbus^® data functions as well as some control functions. The functions to perform PLC program download and other device specific functions are outside the scope of this package.

All functions of conformance Class 0 and Class 1 have been implemented. In addition the most frequent used functions of conformance Class 2 have been implemented.

The following table lists the available FieldTalk Master Protocol Pack functions:

Function Code Current Terminology Classic Terminology

Conformance Class 0

3 (03 hex) Read Multiple Registers Read Holding Registers

16 (10 hex) Write Multiple Registers Preset Multiple Registers

Conformance Class 1

1 (01 hex) Read Coils Read Coil Status

2 (02 hex) Read Inputs Discretes Read Input Status

4 (04 hex) Read Input Registers Read Input Registers

5 (05 hex) Write Coil Force Single Coil

6 (06 hex) Write Single Register Preset Single Register

7 (07 hex) Read Exception Status Read Exception Status

Conformance Class 2

15 (0F hex) Force Multiple Coils Force Multiple Coils

22 (16 hex) Mask Write Register Mask Write Register

23 (17 hex) Read/Write Registers Read/Write Registers

Vendor Specific

100 (64 hex) Read Log History

n/a Send/Receive ADAM 5000/6000 ASCII command

Remarks:: When passing register numbers and discrete numbers to FieldTalk functions you have to use the the Modbus register and discrete numbering scheme. See Register and Discrete Numbering Scheme. (Internally the functions will deduct 1 from the start register value before transmitting the value to the slave device.)
Most slave devices are limiting the amount of registers to be exchanged with the ASCII protocol to be 62 registers or 496 discretes. The limitation is based on the fact that the buffer must not exceed 256 bytes.

All master data and control functions are designed thread-safe. All methods of a particular MbusMaster... object can only be accessed by one thread at the same time. In addition, access to the register array objects is synchronized to allow concurrent access. This enables one thread to update a register array while a second thread is sending the data to a Modbus slave. In this case the update thread must also synchronize his access to the register array by embedding the access into a synchronized(regArr) clause.

Using multiple instances of a MbusMaster... class enables concurrent protocol transfer on different communication channels (e.g. multiple TCP/IP sessions in separate threads or multiple COM ports in separate threads).

Compounds

class MbusMasterFunctions

This base class implements the Modbus^® master functions. More...

Class 0 Modbus Functions

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.writeMultipleRegisters (int slaveAddr, int startRef, short[] regArr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.writeMultipleRegisters (int slaveAddr, int startRef, int[] int32Arr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.writeMultipleRegisters (int slaveAddr, int startRef, float[] float32Arr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readMultipleRegisters (int slaveAddr, int startRef, short[] regArr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readMultipleRegisters (int slaveAddr, int startRef, int[] int32Arr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readMultipleRegisters (int slaveAddr, int startRef, float[] float32Arr) throws IOException, BusProtocolException

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

Class 1 Modbus Functions

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readCoils (int slaveAddr, int startRef, boolean[] bitArr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readInputDiscretes (int slaveAddr, int startRef, boolean[] bitArr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readInputRegisters (int slaveAddr, int startRef, short[] regArr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readInputRegisters (int slaveAddr, int startRef, int[] int32Arr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readInputRegisters (int slaveAddr, int startRef, float[] float32Arr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.writeCoil (int slaveAddr, int bitAddr, boolean bitVal) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.writeSingleRegister (int slaveAddr, int regAddr, short regVal) throws IOException, BusProtocolException

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

synchronized byte com::focus_sw::fieldtalk::MbusMasterFunctions.readExceptionStatus (int slaveAddr) throws IOException, BusProtocolException

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

Class 2 Modbus Functions

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.forceMultipleCoils (int slaveAddr, int startRef, boolean[] bitArr) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.maskWriteRegister (int slaveAddr, int regAddr, short andMask, short orMask) throws IOException, BusProtocolException

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.readWriteRegisters (int slaveAddr, int readRef, short[] readArr, int writeRef, short[] writeArr) throws IOException, BusProtocolException

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

Protocol Configuration

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.setTimeout (int timeOut)

Configures time-out.

int com::focus_sw::fieldtalk::MbusMasterFunctions.getTimeout ()

Returns the operation time-out value.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.setPollDelay (int pollDelay)

Configures poll delay.

int com::focus_sw::fieldtalk::MbusMasterFunctions.getPollDelay ()

Returns the poll delay time.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.setRetryCnt (int retryCnt)

Configures the automatic retry setting.

int com::focus_sw::fieldtalk::MbusMasterFunctions.getRetryCnt ()

Returns the automatic retry count.

Transmission Statistic Functions

synchronized long com::focus_sw::fieldtalk::MbusMasterFunctions.getTotalCounter ()

Returns how often a transmit/receive cycle has been executed.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.resetTotalCounter ()

Resets total transmit/receive cycle counter.

synchronized long com::focus_sw::fieldtalk::MbusMasterFunctions.getSuccessCounter ()

Returns how often a transmit/receive cycle was successful.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.resetSuccessCounter ()

Resets successful transmit/receive counter.

Slave Configuration

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureStandard32BitMode ()

Configures all slaves for Standard 32-bit Mode.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureStandard32BitMode (int slaveAddr)

Configures a slave for Standard 32-bit Register Mode.

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureSingleReg32BitMode ()

Configures all slaves for Single Register 32-bit Mode.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureSingleReg32BitMode (int slaveAddr)

Configures all slaves for Single Register 32-bit Mode.

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureCountFromOne ()

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureCountFromOne (int slaveAddr)

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

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureCountFromZero ()

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

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureCountFromZero (int slaveAddr)

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

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureLittleEndianInts ()

Disables word swapping for int data type functions for all slaves.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureLittleEndianInts (int slaveAddr)

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

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureBigEndianInts ()

Configures int data type functions to do a word swap for all slaves.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureBigEndianInts (int slaveAddr)

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

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureLittleEndianFloats ()

Disables float data type functions to do a word swap for all slaves.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureLittleEndianFloats (int slaveAddr)

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

void com::focus_sw::fieldtalk::MbusMasterFunctions.configureSwappedFloats ()

Configures float data type functions to do a word swap for all slaves.

synchronized void com::focus_sw::fieldtalk::MbusMasterFunctions.configureSwappedFloats (int slaveAddr)

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

Function Documentation

synchronized void writeMultipleRegisters ( int slaveAddr,

int startRef,

short[] regArr

) throws IOException, BusProtocolException [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 - 247)

startRef Start reference (Range depends on configuration setting)

regArr Buffer with the data to be sent. The length of the array determines how many registers are sent (Range: 1-100).

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
Broadcast supported for serial protocols

synchronized void readCoils ( int slaveAddr,

int startRef,

boolean[] bitArr

) throws IOException, BusProtocolException [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 - 247)

startRef Start reference (Range: depends on configuration setting)

bitArr Buffer which will contain the data read

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void forceMultipleCoils ( int slaveAddr,

int startRef,

boolean[] bitArr

) throws IOException, BusProtocolException [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 - 247)

startRef Start reference (Range: depends on configuration setting)

bitArr Buffer which contains the data to be sent

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
Broadcast supported for serial protocols

synchronized void setTimeout ( int timeOut ) [inherited]

Configures time-out.
This function sets the time-out to the specified value. A value of 0 disables the time-out, which causes all subsequent calls to data and control functions to block.
Note:
A port or connection must be closed in order to configure it.

Parameters:

timeOut Timeout value in ms (Range: 0 - 100000), 0 disables time-out

Exceptions:

IllegalStateException Port is open

IllegalArgumentException Parameter is out of range

synchronized long getTotalCounter ( ) [inherited]

Returns how often a transmit/receive cycle has been executed.

Returns:
Counter value

void 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

synchronized void writeMultipleRegisters ( int slaveAddr,

int startRef,

int[] int32Arr

) throws IOException, BusProtocolException [inherited]

Modbus function 16 (10 hex) for 32-bit int data types, Preset Multiple Registers/Write Multiple Registers with int data.
Writes int values into a pairs of output registers (holding registers, 4:00000 table).
Remarks:
Depending on the 32-bit Mode setting, an int will be transferred as two consecutive 16-bit registers (Standard) or as one 32-bit register (Daniel/Enron).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 0 - 247)

startRef Start reference (Range: depends on configuration setting)

int32Arr Buffer with the data to be sent. The length of the array determines how many registers are sent (Range: 1-50).

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
Broadcast supported for serial protocols

synchronized void writeMultipleRegisters ( int slaveAddr,

int startRef,

float[] float32Arr

) throws IOException, BusProtocolException [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 a pairs of output registers (holding registers, 4:00000 table).
Remarks:
Depending on the 32-bit Mode setting, an int will be transferred as two consecutive 16-bit registers (Standard) or as one 32-bit register (Daniel/Enron).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 0 - 247)

startRef Start reference (Range: depends on configuration setting)

float32Arr Buffer with the data to be sent. The length of the array determines how many registers are sent (Range: 1-50).

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
Broadcast supported for serial protocols

synchronized void readMultipleRegisters ( int slaveAddr,

int startRef,

short[] regArr

) throws IOException, BusProtocolException [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 - 247)

startRef Start reference (Range: depends on configuration setting)

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:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readMultipleRegisters ( int slaveAddr,

int startRef,

int[] int32Arr

) throws IOException, BusProtocolException [inherited]

Modbus function 3 (03 hex) for 32-bit int data types, Read Holding Registers/Read Multiple Registers as int data.
Reads the contents of pairs of two consecutive output registers (holding registers, 4:00000 table) into float values.

Remarks:
Depending on the 32-bit Mode setting, an int will be transferred as two consecutive 16-bit registers (Standard) or as one 32-bit register (Daniel/Enron).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247)

startRef Start reference (Range: depends on configuration setting)

int32Arr Buffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-62).

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readMultipleRegisters ( int slaveAddr,

int startRef,

float[] float32Arr

) throws IOException, BusProtocolException [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 two consecutive output registers (holding registers, 4:00000 table) into float values.

Remarks:
Depending on the 32-bit Mode setting, an int will be transferred as two consecutive 16-bit registers (Standard) or as one 32-bit register (Daniel/Enron).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247)

startRef Start reference (Range: depends on configuration setting)

float32Arr Buffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-62).

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readInputDiscretes ( int slaveAddr,

int startRef,

boolean[] bitArr

) throws IOException, BusProtocolException [inherited]

Modbus function 2 (02 hex), Read Inputs Status/Read Input Discretes.
Reads the contents of the discrete inputs (coils, 1:00000 table).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247)

startRef Start reference (Range: depends on configuration setting)

bitArr Buffer which will contain the data read

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readInputRegisters ( int slaveAddr,

int startRef,

short[] regArr

) throws IOException, BusProtocolException [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 - 247)

startRef Start reference (Range: depends on configuration setting)

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:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readInputRegisters ( int slaveAddr,

int startRef,

int[] int32Arr

) throws IOException, BusProtocolException [inherited]

Modbus function 4 (04 hex) for 32-bit int data types, Read Input Registers as int data.
Reads the contents of pairs of two consecutive input registers (3:00000 table) into float values.

Remarks:
Depending on the 32-bit Mode setting, an int will be transferred as two consecutive 16-bit registers (Standard) or as one 32-bit register (Daniel/Enron).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247)

startRef Start reference (Range: depends on configuration setting)

int32Arr Buffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-62).

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readInputRegisters ( int slaveAddr,

int startRef,

float[] float32Arr

) throws IOException, BusProtocolException [inherited]

Modbus function 4 (04 hex) for 32-bit float data types, Read Input Registers as float data.
Reads the contents of pairs of two consecutive input registers (3:00000 table) into float values.

Remarks:
Depending on the 32-bit Mode setting, an int will be transferred as two consecutive 16-bit registers (Standard) or as one 32-bit register (Daniel/Enron).

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247)

startRef Start reference (Range: depends on configuration setting)

float32Arr Buffer which will be filled with the data read. The length of the array determines how many registers are read (Range: 1-62).

Exceptions:

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void writeCoil ( int slaveAddr,

int bitAddr,

boolean bitVal

) throws IOException, BusProtocolException [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 - 247)

bitAddr Coil address (Range: depends on configuration setting)

bitVal true sets, false clears discrete output variable

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
Broadcast supported for serial protocols

synchronized void writeSingleRegister ( int slaveAddr,

int regAddr,

short regVal

) throws IOException, BusProtocolException [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 - 247)

regAddr Register address (Range: depends on configuration setting)

regVal Data to be sent

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
Broadcast supported for serial protocols

synchronized byte readExceptionStatus ( int slaveAddr ) throws IOException, BusProtocolException [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 - 247)

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void maskWriteRegister ( int slaveAddr,

int regAddr,

short andMask,

short orMask

) throws IOException, BusProtocolException [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 andMask)

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247)

regAddr Register address (Range: depends on configuration setting)

andMask Mask to be applied as a logic AND to the register

orMask Mask to be applied as a logic OR to the register

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

synchronized void readWriteRegisters ( int slaveAddr,

int readRef,

short[] readArr,

int writeRef,

short[] writeArr

) throws IOException, BusProtocolException [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 - 247)

readRef Start reference for reading (Range: depends on configuration setting)

readArr Buffer which will contain the data read. The length of the array determines how many registers are read (Range: 1-125).

writeRef Start reference for writing (Range: depends on configuration setting)

writeArr Buffer with data to be sent. The length of the array determines how many registers are sent (Range: 1-100).

Exceptions:

IllegalStateException Port or connection is closed

IOException An I/O error occured

IllegalArgumentException A parameter is out of range

BusProtocolException A protocol failure occured. See descendants of BusProtocolException for a more detailed failure list.

Note:
No broadcast supported

int getTimeout ( ) [inherited]

Returns the operation time-out value.

Returns:
Timeout value in ms

synchronized void setPollDelay ( int 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.
Note:
A port or connection must be closed in order to configure it.

Parameters:

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

Exceptions:

IllegalStateException Port is open

IllegalArgumentException Parameter is out of range

int getPollDelay ( ) [inherited]

Returns the poll delay time.

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

synchronized void setRetryCnt ( int retryCnt ) [inherited]

Configures the automatic retry setting.
A value of 0 disables any automatic retries.
Note:
A port or connection must be closed in order to configure it.

Parameters:

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

Exceptions:

IllegalStateException Port is open

IllegalArgumentException Parameter is out of range

int getRetryCnt ( ) [inherited]

Returns the automatic retry count.

Returns:
Retry count

synchronized long getSuccessCounter ( ) [inherited]

Returns how often a transmit/receive cycle was successful.

Returns:
Counter value

synchronized void configureStandard32BitMode ( int 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 - 247). A value of zero configures the behaviour for broadcasting.

Remarks:
This is the default mode

void configureSingleReg32BitMode ( ) [inherited]

Configures all slaves for Single Register 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.

synchronized void configureSingleReg32BitMode ( int slaveAddr ) [inherited]

Configures all slaves for Single Register 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 - 247). A value of zero configures the behaviour for broadcasting.

void configureCountFromOne ( ) [inherited]

Configures the reference counting scheme to start with one for all slaves.
This renders the reference range to be 1 to 0x10000 and register #0 is an illegal register.

Remarks:
This is the default mode

synchronized void configureCountFromOne ( int slaveAddr ) [inherited]

Configures a slave's reference counting scheme to start with one.
This renders the reference range to be 1 to 0x10000 and register #0 is an illegal register.

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247). A value of zero configures the behaviour for broadcasting.

Remarks:
This is the default mode

void configureCountFromZero ( ) [inherited]

Configures the reference counting scheme to start with zero for all slaves.
This renders the valid reference range to be 0 to 0xFFFF.
This renders the first register to be #0 for all slaves.

synchronized void configureCountFromZero ( int slaveAddr ) [inherited]

Configures a slave's reference counting scheme to start with zero.
This renders the valid reference range to be 0 to 0xFFFF.

Parameters:

slaveAddr Modbus address of slave device or unit identifier (Range: 1 - 247). A value of zero configures the behaviour for broadcasting.

void configureLittleEndianInts ( ) [inherited]

Disables word swapping for int data type functions for all slaves.
Modbus is using little-endian word order for 32-bit values. This setting assumes that the slave also serves 32-bit data in in little little-endian word order.

Remarks:
This is the default mode

synchronized void configureLittleEndianInts ( int 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 - 247). A value of zero configures the behaviour for broadcasting.

void configureBigEndianInts ( ) [inherited]

Configures int data type functions to do a word swap for all slaves.
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.

synchronized void configureBigEndianInts ( int 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 - 247). A value of zero configures the behaviour for broadcasting.

void configureLittleEndianFloats ( ) [inherited]

Disables float data type functions to do a word swap for all slaves.
Modbus is using little-endian word order for 32-bit values. This setting assumes that the slaves also serves 32-bit floats in little little-endian word order which is the most common case.

Remarks:
This is the default mode

synchronized void configureLittleEndianFloats ( int 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 - 247). A value of zero configures the behaviour for broadcasting.

void configureSwappedFloats ( ) [inherited]

Configures float data type functions to do a word swap for all slaves.
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.

synchronized void configureSwappedFloats ( int 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 - 247). A value of zero configures the behaviour for broadcasting.


Back \| Top of page			Info \| Support \| Contact \| About

Information in this document is subject to change without notice. Copyright © 2000-2007 proconX Pty Ltd. All rights reserved.
All product and brand names mentioned on this page may be trademarks or registered trademarks of their respective owners.