PlcNull Members

Namespace: IPS7Lnk.Advanced
Assemblies: IPS7LnkNet.Advanced.dll, IPS7LnkNet.Advanced.dll
The PlcNull type exposes the following members.

PlcNull(PlcAddress)

Initializes a new instance of the PlcNull class using the specified address.

C#

public PlcNull(PlcAddress address)


Parameters

address PlcAddress

The address there the logical null value is to be located.


Exceptions

ArgumentNullException

The address is a null reference (Nothing in Visual Basic).

PlcNull(PlcAddress, Int32)

Initializes a new instance of the PlcNull class using the specified address and length.

C#

public PlcNull(PlcAddress address, int length)


Parameters

address PlcAddress

The address there the logical null value is to be located.

length Int32

The reserved amount of address specific Bit's, Byte's, Word's or DWord's represented as null values.


Exceptions

ArgumentNullException

The address is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

The length is lower than one.

Description

Gets or sets more meaningful information about the value and its usage than only using the Name property.

C#

public string Description { get; set; }


Property Value

String

A String value containing additional information about the value and its usage.

Name

Gets the name of the value represented.

C#

public PlcName Name { get; }


Property Value

PlcName

An instance of the PlcName class containing the name of the value represented.

Tag

Gets or sets the object that contains additional user data about the value.

C#

public object Tag { get; set; }


Property Value

Object

An Object that contains additional user data about the value. The default is null (Nothing in Visual Basic).

Type

Gets the type of value represented by the PLC value.

C#

public PlcType Type { get; }


Property Value

PlcType

The PlcType of the value represented by the PLC value.

IsValidType(Object)

Determines whether a specified value is acceptable for this PlcNull.

C#

public bool IsValidType(object value)


Parameters

value Object

The value to check.


Returns

Boolean

The value true, if the specified value is the Type or an acceptable derived type; otherwise the value false.

IsValidValue(Object)

Determines whether the provided value is accepted for the type of PLC value through basic type checking and also potentially if it is within the allowed range of value for that type.

C#

public bool IsValidValue(object value)


Parameters

value Object

The value to check.


Returns

Boolean

The value true, if the specified value is acceptable and is of the correct type or a derived type; otherwise the value false.

Relocate(Int32)

Relocates the PlcNull using the specified offset. The original PlcNull remains unmodified.

C#

public IPlcValue Relocate(int operandNumber)


Parameters

operandNumber Int32

The operand number offset used to adjust the address of the Type.


Returns

IPlcValue

A new instance of the PlcNull configured with the same metadata as this instance but relocated using the specified offset.



Exceptions

ArgumentOutOfRangeException

The offset specified by operandNumber result into a new value that would be out of the bounds defined by MinOperandNumber or MaxOperandNumber.

InvalidOperationException

It is not possible to relocate relative types.

Relocate(Int32, Int32)

Relocates the PlcNull using the specified offset. The original PlcNull remains unmodified.

C#

public IPlcValue Relocate(int operandNumber, int byteNumber)


Parameters

operandNumber Int32

The operand number offset used to adjust the address of the Type.

byteNumber Int32

The byte number offset used to adjust the address of the Type.


Returns

IPlcValue

A new instance of the PlcNull configured with the same metadata as this instance but relocated using the specified offset.



Exceptions

ArgumentOutOfRangeException

One of the offsets specified by operandNumber or byteNumber result into a new value that would be out of the bounds defined by MinOperandNumber, MaxOperandNumber, MinByteNumber and MaxByteNumber.

InvalidOperationException

It is not possible to relocate relative types.

Relocate(Int32, Int32, Int32)

Relocates the PlcNull using the specified offset. The original PlcNull remains unmodified.

C#

public IPlcValue Relocate(int operandNumber, int byteNumber, int bitNumber)


Parameters

operandNumber Int32

The operand number offset used to adjust the address of the Type.

byteNumber Int32

The byte number offset used to adjust the address of the Type.

bitNumber Int32

The bit number offset used to adjust the address of the Type.


Returns

IPlcValue

A new instance of the PlcNull configured with the same metadata as this instance but relocated using the specified offset.



Exceptions

ArgumentOutOfRangeException

One of the offsets specified by operandNumber, byteNumber or bitNumber result into a new value that would be out of the bounds defined by MinOperandNumber, MaxOperandNumber, MinByteNumber, MaxByteNumber, MinBitNumber or MaxBitNumber.

InvalidOperationException

It is not possible to relocate relative types.

Relocate(PlcAddress)

Relocates the PlcNull using the specified address. The original PlcNull remains unmodified.

C#

public IPlcValue Relocate(PlcAddress address)


Parameters

address PlcAddress

The PlcAddress to that the type is to be relocated.


Returns

IPlcValue

A new instance of the PlcNull configured with the same metadata as this instance but relocated using the specified address.



Exceptions

ArgumentNullException

The address is a null reference (Nothing in Visual Basic).

InvalidOperationException

It is not possible to relocate absolute object types without relative type information.


Remarks

The RawType of the address specified needs to be the same as defined by the address of the Type of the PLC value.

ToString()

Converts the value to its string representation.

C#

public override string ToString()


Returns

String

A string that contains the value.

ValidateValue(Object)

Validates the specified value whether it can be assigned to this PlcValue┬┤1.

C#

public void ValidateValue(object value)


Parameters

value Object

The value to validate.



Exceptions

ArgumentException

The value or its type is not valid.