ModbusMasterSerialPort

Namespace

ZEquipment

Implements

IModbusMasterRtu

IObject

IError

FUNCTION_BLOCK ModbusMasterSerialPort IMPLEMENTS ZCore.IModbusMasterRtu, ZCore.IObject, ZCore.IError

This function block implements a Modbus master in order to be able to address a Modbus device via a serial interface. The Beckhoff function block ModbusRtuMaster_KL6x22B is used internally. -- ModbusRtuMaster_KL6x22B The data structures required for the link with the serial communication port are included in the Beckhoff function block.

The following Modbus function codes are supported

• Read Coils (0x01): to read contiguous status of coils
• Read Discrete Inputs (0x02): to read contiguous status of discrete inputs
• Read Holding Registers (0x03): to read the contents of a contiguous block of holding registers
• Read Input Register (0x04): to read from contiguous input registers
• Write Single Coil (0x05): to write a single output to either ON or OFF
• Write Single register (0x06): to write a single holding register
• Write Multiple Coils (0x0F): to force each coil in a sequence of coils to either ON or OFF
• Write Multiple Registers (0x10): to write a block of contiguous registers

Since only one request can be active at a serial interface at the same time, the requests are bufferd internally and processed on after the other.

This function block is the managed user object of ModbusMasterSerialPortImpl for use inside the framework.

Constructor

FB_init

METHOD FB_init (
 [input] bInitRetains : BOOL,
 [input] bInCopyCode : BOOL,
 [input] parent : ZCore.IManagedObject,
 [input] logger : ZCore.ILogger) : BOOL

When constructing this object a logging device can be specified.

Inputs

bInitRetains BOOL

bInCopyCode BOOL

parent IManagedObject

Interface to the ManagedObject that is the parent of this object

logger ILogger

if wanted, interface to an external housed logging device like LoggerFile7FF

Returns

BOOL

Properties

Busy

PROPERTY Busy : BOOL

This property returns TRUE if the object is Busy executing a sequence or still in its initialization phase (if applicable). It returns FALSE if the object is Idle or in an Error state.

Property Value

BOOL

Done

PROPERTY Done : BOOL

If the object is in idle state (often mentioned as "the object is not busy and not on error"), this is indicated by this property returning TRUE.

Property Value

BOOL

Error

PROPERTY Error : BOOL

If the object aborts its execution with an error, this is indicated by this property returning TRUE. Information about the error may be retrieved by utilizing the methods that are implemented from the IError.

Returns TRUE if a fault occured within a sequence or the initialization phase of an object, respectively. If this property returns TRUE, use

• ErrorMessage
• ErrorId
• ErrorSource
• TraceErrorStack

to get insights about the origin of the fault.

Property Value

BOOL

Methods

ErrorId

METHOD ErrorId () : UDINT

Returns the error code of the first error source for this object. The method recursively goes down the error stack until the initial source of error of this object can be found. For performance reasons, the error stack is not cleared when the error state is reset. So this method should always used in conjunction with Error.

Returns

UDINT

ErrorMessage

METHOD ErrorMessage () : ZCore.ZString

Returns the error description of the first error source for this object. The method recursively goes down the error stack until the initial source of error of this object can be found. For performance reasons, the error stack is not cleared when the error state is reset. So this method should always used in conjunction with Error.

Returns

ZString

ErrorSource

METHOD ErrorSource () : ZCore.IError

This method returns the direct error source of this object. This method can then be used to retrieve the actual error source by using the method of the returned IError.

Returns

IError

ReadCoilsAsync

METHOD ReadCoilsAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] quantity : DWORD,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

quantity DWORD

defines the quantity (number) of the coils to be read

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method writes to

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

ReadDiscreteInputsAsync

METHOD ReadDiscreteInputsAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] quantity : DWORD,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

Use this function to read the status of discrete inputs in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

quantity DWORD

defines the quantity (number) of inputs to be read

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method writes to

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

ReadHoldingRegisterAsync

METHOD ReadHoldingRegisterAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] quantity : DWORD,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

This method is used to read the contents of a contiguous block of holding registers in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

quantity DWORD

defines the quantity (number) of registgers to be read parameters

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method writes to

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

ReadInputRegisterAsync

METHOD ReadInputRegisterAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] quantity : DWORD,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

This method is used to read from contiguous input registers in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

quantity DWORD

defines the quantity (number) of registers to be read

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method writes to

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

SetLogger

METHOD SetLogger (
 [input] logger : ZCore.ILogger)

Use this function to enable logging for this modbus master instance. If logging is enabled, every parameter request (Read and Write) is written to the logger.

If no Logging Instance is given here (logger=0), logging is generally deactivated.

Inputs

logger ILogger

TraceErrorStack

METHOD TraceErrorStack (
 [input] trace : ZCore.IErrorTrace)

This method is used internally when recording an error trace.

Inputs

trace IErrorTrace

WriteMultipleCoilsAsync

METHOD WriteMultipleCoilsAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] quantity : DWORD,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

This method is used to force each coil in a sequence of coils either ON or OFF in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

quantity DWORD

defines the quantity (number) of coils to be written

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method reads from

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

WriteMultipleRegisterAsync

METHOD WriteMultipleRegisterAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] quantity : DWORD,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

This method is used to write a block of contiguous registers in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

quantity DWORD

defines the quantity (count) of registers to be written

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method reads from

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

WriteSingleCoilAsync

METHOD WriteSingleCoilAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

This method is used to write a single output to eithe ON or OFF in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method reads from

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s

WriteSingleRegisterAsync

METHOD WriteSingleRegisterAsync (
 [input] taskToken : ZCore.ITaskToken,
 [input] unitId : BYTE,
 [input] modbusAddress : DWORD,
 [input] bufferPtr : ZCore.ZPointer,
 [input] bufferSize : UDINT,
 [input] timeout : LREAL)

This method is used ot write a singel hlding register in a remote device.

Inputs

taskToken ITaskToken

unitId BYTE

defines the station address of the target device for ModbusRTU

modbusAddress DWORD

defines the modbus starting address of the server on which the operation should take place

bufferPtr ZPointer

Pointer to the location this method writes to

bufferSize UDINT

Size of the location buffer is pointing to

timeout LREAL

Timeout value for waiting for a response frome the slave in s