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Data and Control Functions for all Protocol Flavours
Detailed Description
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 library.
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. This rich function set enables a user to solve nearly every Modbus data transfer problem.
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 |
- 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.
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Class 0 Modbus Functions |
| | TMbusMasterFunctions::writeMultipleRegisters (integer slaveAddr, integer startRef, word &*regArr) |
| | Modbus function 16 (10 hex), Preset Multiple Registers/Write Multiple Registers.
|
| | TMbusMasterFunctions::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.
|
| | TMbusMasterFunctions::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.
|
| | TMbusMasterFunctions::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.
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| | TMbusMasterFunctions::readMultipleRegisters (integer slaveAddr, integer startRef, word &*regArr) |
| | Modbus function 3 (03 hex), Read Holding Registers/Read Multiple Registers.
|
| | TMbusMasterFunctions::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.
|
| | TMbusMasterFunctions::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.
|
| | TMbusMasterFunctions::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.
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Class 1 Modbus Procedures |
| | TMbusMasterFunctions::readCoils (integer slaveAddr, integer startRef, boolean &*bitArr) |
| | Modbus function 1 (01 hex), Read Coil Status/Read Coils.
|
| | TMbusMasterFunctions::readInputDiscretes (integer slaveAddr, integer startRef, boolean &*bitArr) |
| | Modbus function 2 (02 hex), Read Inputs Status/Read Input Discretes.
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| | TMbusMasterFunctions::readInputRegisters (integer slaveAddr, integer startRef, word &*regArr) |
| | Modbus function 4 (04 hex), Read Input Registers.
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| | TMbusMasterFunctions::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.
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| | TMbusMasterFunctions::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.
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| | TMbusMasterFunctions::readInputFloats (integer slaveAddr, integer startRef, single &*float32Arr) |
| | Modbus function 4 (04 hex) for 32-bit float data types, Read Input Registers as float data.
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| | TMbusMasterFunctions::writeCoil (integer slaveAddr, integer bitAddr, boolean bitVal) |
| | Modbus function 5 (05 hex), Force Single Coil/Write Coil.
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| | TMbusMasterFunctions::writeSingleRegister (integer slaveAddr, integer regAddr, word regVal) |
| | Modbus function 6 (06 hex), Preset Single Register/Write Single Register.
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| | TMbusMasterFunctions::readExceptionStatus (integer slaveAddr, byte &statusByte) |
| | Modbus function 7 (07 hex), Read Exception Status.
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Class 2 Modbus Procedures |
| | TMbusMasterFunctions::forceMultipleCoils (integer slaveAddr, integer startRef, boolean &*bitArr) |
| | Modbus function 15 (0F hex), Force Multiple Coils.
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| | TMbusMasterFunctions::maskWriteRegister (integer slaveAddr, integer regAddr, word andMask, word orMask) |
| | Modbus function 22 (16 hex), Mask Write Register.
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| | TMbusMasterFunctions::readWriteRegisters (integer slaveAddr, integer readRef, word &*readArr, integer writeRef, word &*writeArr) |
| | Modbus function 23 (17 hex), Read/Write Registers.
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Protocol Configuration |
| | TMbusMasterFunctions::setTimeout (const integer timeOut) |
| | Configures time-out.
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| integer | TMbusMasterFunctions::getTimeout () |
| | Returns the time-out value.
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| | TMbusMasterFunctions::setPollDelay (const integer pollDelay) |
| | Configures poll delay.
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| integer | TMbusMasterFunctions::getPollDelay () |
| | Returns the poll delay time.
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| | TMbusMasterFunctions::setRetryCnt (const integer retryCnt) |
| | Configures the automatic retry setting.
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| integer | TMbusMasterFunctions::getRetryCnt () |
| | Returns the automatic retry count.
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| integer | TMbusMasterFunctions::timeout |
| integer | TMbusMasterFunctions::pollDelay |
| integer | TMbusMasterFunctions::retryCnt |
| boolean | TMbusMasterFunctions::bigEndianInts |
| boolean | TMbusMasterFunctions::swappedFloats |
Transmission Statistic Functions |
| cardinal | TMbusMasterFunctions::getTotalCounter () |
| | Returns how often a message transfer has been executed.
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| TMbusMasterFunctions::resetTotalCounter () |
| | Resets total message transfer counter.
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| cardinal | TMbusMasterFunctions::getSuccessCounter () |
| | Returns how often a message transfer was successful.
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| TMbusMasterFunctions::resetSuccessCounter () |
| | Resets successful message transfer counter.
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Word Order Configuration |
| | TMbusMasterFunctions::configureBigEndianInts () |
| | Configures int data type functions to do a word swap.
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| | TMbusMasterFunctions::configureSwappedFloats () |
| | Configures float data type functions to do a word swap.
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| | TMbusMasterFunctions::configureLittleEndianInts () |
| | Configures int data type functions not to do a word swap.
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| | TMbusMasterFunctions::configureIeeeFloats () |
| | Configures float data type functions not to do a word swap.
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Functions |
| string | TMbusMasterFunctions::getPackageVersion () |
| | Returns the package version number.
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Function Documentation
| writeMultipleRegisters |
( |
integer |
slaveAddr, |
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|
integer |
startRef, |
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word &* |
regArr |
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) |
[inherited] |
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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 reference (Range: 1 - $10000) |
| regArr | Buffer with the data to be sent.The length of the array determines how many registers are written (Range: 1-100). |
- 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
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| readCoils |
( |
integer |
slaveAddr, |
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integer |
startRef, |
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boolean &* |
bitArr |
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) |
[inherited] |
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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 - $10000) |
| 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 |
- Note:
- No broadcast supported
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| forceMultipleCoils |
( |
integer |
slaveAddr, |
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integer |
startRef, |
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boolean &* |
bitArr |
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) |
[inherited] |
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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 - $10000) |
| bitArr | Buffer which contains the data to be sent. The length of the array determines how many coils are written (Range: 1-800). |
- 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 |
- Note:
- Broadcast supported for serial protocols
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| setTimeout |
( |
const integer |
timeOut |
) |
[inherited] |
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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 |
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| cardinal getTotalCounter |
( |
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) |
[inherited] |
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Returns how often a message transfer has been executed.
- Returns:
- Counter value
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| configureBigEndianInts |
( |
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) |
[inherited] |
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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. |
| class string getPackageVersion |
( |
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) |
[inherited] |
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Returns the package version number.
- Returns:
- Package version string
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| writeMultipleLongInts |
( |
integer |
slaveAddr, |
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integer |
startRef, |
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integer &* |
int32Arr |
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) |
[inherited] |
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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 - $10000) |
| int32Arr | Buffer with the data to be sent. The length of the array determines how many references are read (Range: 1-50). |
- 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 |
- Note:
- Broadcast supported for serial protocols
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| writeMultipleMod10000 |
( |
integer |
slaveAddr, |
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|
integer |
startRef, |
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integer &* |
int32Arr |
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) |
[inherited] |
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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 - $10000) |
| int32Arr | Buffer with the data to be sent. The length of the array determines how many references are written (Range: 1-50). |
- 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 |
- Note:
- Broadcast supported for serial protocols
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| writeMultipleFloats |
( |
integer |
slaveAddr, |
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|
integer |
startRef, |
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single &* |
float32Arr |
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) |
[inherited] |
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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 - $10000) |
| float32Arr | Buffer with the data to be sent. The length of the array determines how many references are written (Range: 1-50). |
- 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 |
- Note:
- Broadcast supported for serial protocols
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| readMultipleRegisters |
( |
integer |
slaveAddr, |
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|
integer |
startRef, |
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|
word &* |
regArr |
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) |
[inherited] |
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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 reference (Range: 1 - $10000) |
| 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 |
- Note:
- No broadcast supported
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| readMultipleLongInts |
( |
integer |
slaveAddr, |
|
|
integer |
startRef, |
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integer &* |
int32Arr |
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) |
[inherited] |
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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 - $10000) |
| int32Arr | Buffer which will be filled with the data read. The length of the array determines how many references 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 |
- Note:
- No broadcast supported
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| readMultipleMod10000 |
( |
integer |
slaveAddr, |
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|
integer |
startRef, |
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integer &* |
int32Arr |
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) |
[inherited] |
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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 - $10000) |
| int32Arr | Buffer which will be filled with the data read. The length of the array determines how many references 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 |
- Note:
- No broadcast supported
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| readMultipleFloats |
( |
integer |
slaveAddr, |
|
|
integer |
startRef, |
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single &* |
float32Arr |
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) |
[inherited] |
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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 - $10000) |
| float32Arr | Buffer which will be filled with the data read. The length of the array determines how many references 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 |
- Note:
- No broadcast supported
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| readInputDiscretes |
( |
integer |
slaveAddr, |
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integer |
startRef, |
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boolean &* |
bitArr |
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) |
[inherited] |
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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 - $10000) |
| 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 |
- Note:
- No broadcast supported
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| readInputRegisters |
( |
integer |
slaveAddr, |
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integer |
startRef, |
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word &* |
regArr |
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) |
[inherited] |
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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 reference (Range: 1 - $10000) |
| 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 |
- Note:
- No broadcast supported
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| readInputLongInts |
( |
integer |
slaveAddr, |
|
|
integer |
startRef, |
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integer &* |
int32Arr |
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) |
[inherited] |
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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 - $10000) |
| int32Arr | Buffer which will be filled with the data read. The length of the array determines how many references 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 |
- Note:
- No broadcast supported
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| readInputMod10000 |
( |
integer |
slaveAddr, |
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|
integer |
startRef, |
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integer &* |
int32Arr |
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) |
[inherited] |
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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 - $10000) |
| int32Arr | Buffer which will be filled with the data read. The length of the array determines how many references 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 |
- Note:
- No broadcast supported
|
| readInputFloats |
( |
integer |
slaveAddr, |
|
|
integer |
startRef, |
|
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single &* |
float32Arr |
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) |
[inherited] |
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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 - $10000) |
| float32Arr | Buffer which will be filled with the data read. The length of the array determines how many references 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 |
- Note:
- No broadcast supported
|
| writeCoil |
( |
integer |
slaveAddr, |
|
|
integer |
bitAddr, |
|
|
boolean |
bitVal |
|
) |
[inherited] |
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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 - $10000) |
| 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 |
- Note:
- Broadcast supported for serial protocols
|
| 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 - $10000) |
| 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 |
- 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. identifier (Range: 1 - 255) |
- 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 |
- Note:
- No broadcast supported
|
| 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: retVal = (currentVal AND andMask) OR (orMask AND andMask)
- Parameters:
-
| slaveAddr | Modbus address of slave device or unit identifier (Range: 1 - 255) |
| regAddr | Register address (Range: 1 - $10000) |
| 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 reference for reading (Range: 1 - $10000) |
| readArr | Buffer which will contain the data read. The length of the array determines how many references are read (Range: 1-125). |
| writeRef | Start reference for writing (Range: 1 - $10000) |
| writeArr | Buffer with data to be sent. The length of the array determines how many references are written (Range: 1-100). |
- 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 |
- Note:
- No broadcast supported
|
| 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 getSuccessCounter |
( |
|
) |
[inherited] |
|
|
|
Returns how often a message transfer was successful.
- Returns:
- Counter value
|
| 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.
|
| configureLittleEndianInts |
( |
|
) |
[inherited] |
|
|
|
Configures int data type functions not to do a word swap.
This is the default. |
| configureIeeeFloats |
( |
|
) |
[inherited] |
|
|
|
Configures float data type functions not to do a word swap.
This is the default. |
Variable Documentation
integer timeout [inherited]
|
|
|
|
- Note:
- A protocol must be closed in order to configure it.
- See also:
- getTimeout For reading
setTimeout For writing
|
integer pollDelay [inherited]
|
|
|
|
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]
|
|
|
|
- Note:
- A protocol must be closed in order to configure it.
- See also:
- getRetryCnt For reading
setRetryCnt For writing
|
boolean bigEndianInts [inherited]
|
|
|
|
- Note:
- A protocol must be closed in order to configure it.
- See also:
- fSwapInts For reading
setBigEndianInts For writing
|
boolean swappedFloats [inherited]
|
|
|
|
- Note:
- A protocol must be closed in order to configure it.
- See also:
- fSwapFloats For reading
setSwappedFloats For writing
|
|
|
