PLC Client Function Blocks based on IEC 61131-3

UAUserIdentityToken	DataType	Description
UserIdentityTokenType	UAUserIdentityTokenType	Defines the identity Token to authenticate a user during the creation of a Session. See UAUserIdentityTokenType
TokenParam1	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. In case of TokenType “Anonymous” the Param1 will not be evaluated. In case of TokenType “Username” the Param1 contains the user name. In case of TokenType “x509” the Param1 contains the location of the certificate store.
TokenParam2	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. In case of TokenType “Anonymous” the Param2 will not be evaluated. In case of TokenType “Username” the Param2 contains the user password. In case of TokenType “x509” the Param2 contains the certificate name.

5.5.2 UASessionConnectInfo

UASessionConnectInfo	DataType	Description
SessionName	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Defines the name of the session assigned by the client. The name is shown in the diagnostics information of the server. In case of empty string the server will generate a session name.
ApplicationName	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Defines the readable name of the OPC UA client application. The string can be empty.
SecurityMsgMode	UASecurityMsgMode	See UASecurityMsgMode.
SecurityPolicy	UASecurityPolicy	See UASecurityPolicy.
CertificateStore	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Defines the location of the certificate store used for the application certificates and trust lists. The structure of the certificate store is vendor specific. In case of empty string the default certificate store is used.
ClientCertificateName	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Defines the name of the client certificate and private key in the certificate store. In case of empty string the default client application certificate is used. Implementation note: The ApplicationURI will be extracted from the certificate.
ServerUri	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Defines the URI of the server.
CheckServerCertificate	BOOL	Flag indicating if the server certificate should be checked with the trust list of the client application.
TransportProfile	UATransportProfile	See UATransportProfile
UserIdentityToken	UAUserIdentityToken	See UAUserIdentityToken
VendorSpecificParameter	Vendor specific	Vendor may define specific parameters, e.g. in case multiple clients are available, client instance can be defined with this parameter. The VendorSpecificParameter can be empty.
SessionTimeout	TIME	Defines how long the session will survive when there is no connection.
MonitorConnection	TIME	Defines the interval time to check the connection. The connection monitoring has to be done by the client vendor implementation and is defined in OPC 10000-4
LocaleIDs	ARRAY [1..5] OF STRING[6]	OPC 10000-3: <language>[-<country/region>] where <language> is a two letter ISO 639-1:2002 code for language, <country /region> is the three letter ISO 3166 code for the country/region. Sample: en-US, zh-CHS

5.5.3 UANodeID

UANodeID	DataType	Description
NamespaceIndex	UINT
Identifier	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. In case of IdentifierType GUID the format is like 00000316-0000-0000-C000-000001000046 In case of IdentifierType Opaque string has to be base 64 encoded byte string.
IdentifierType	UAIdentifierType	See UAIdentifierType

5.5.4 UAQualifiedName

UAQualifiedName	DataType	Description
NamespaceIndex	UINT	The namespace index to which name is associated.
Name	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Name of the qualified name.

5.5.5 UARelativePathElement

UARelativePathElement	DataType	Description
ReferenceTypeId	UANodeID	See UANodeID. If the ReferenceTypeId is a NULL-UANodeID the reference type is 33 (HierarchicalReferences)
IsInverse	BOOL	If TRUE, the inverse references will be evaluated. Default is FALSE.
IncludeSubtypes	BOOL	If TRUE also subtypes from ReferenceTypeId will be evaluated. Default is TRUE.
TargetName	UAQualifiedName	See UAQualifiedName

5.5.6 UARelativePath

UARelativePath	DataType	Description
NoOfElements	UINT	Number of Elements.
Elements	ARRAY OFUARelativePathElement	See UARelativePathElement. One relative path element. Length of the array is vendor specific MAX_ELEMENTS_RELATIVEPATH See Constants of Array Lengths

5.5.7 UABrowsePath

UABrowsePath	DataType	Description
StartingNode	UANodeID	See UANodeID. Starting NodeId from where the relative path will be evaluated.
RelativePath	UARelativePath	See UARelativePath. The relative path which will be evaluated.

5.5.8 UAMonitoringParameter

UAMonitoringParameter	DataType	Description
SamplingInterval	TIME	The rate in milliseconds the server checks the underlying data source for changes.
QueueSize	UINT	The queue size for the monitoring item.See also 4.2 Monitored Items
DiscardOldest	BOOL	Determine the discard policy in case of queue overflow:TRUE: Discard the oldest in the sample queue FALSE: Discard the newest in the sample queue
DeadbandType	UADeadbandType	See UADeadbandType. This parameter indicates if a deadband is applied and if applied, which type of Deadband.
Deadband	REAL	e.g. percent 0.1%.

5.5.9 UALocalizedText

UALocalizedText	DataType	Description
Locale	STRING[6]	OPC 10000-3: <language>[-<country/region>] where <language> is a two letter ISO639 code for language, <country /region> is the three letter ISO3166 code for the country/region. Sample: en-US, zh-CHS.
Text	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. Contains localized text as string.

5.5.10 UANodeInfo (deprecated)

This UANodeInfo is the first version of declaration – to ease the handling of BrowseName the usage of the second version UANodeInformation is recommended. This also affects

UANodeInformation.

UANodeInfo

DataType

Description

AccessLevel

BYTE

A bit mask indicating whether the current value of the Value Attribute is readable and writable as well as whether the history of the value is readable and changeable.

Bit	Value	AccessLevel
	0x0	None
0	0x1	CurrentRead
1	0x2	CurrentWrite
2	0x4	HistoryRead
3	0x8	HistoryWrite
4
5
6
7

ArrayDimension

ARRAY OFUDINT

The length for each dimension of an array value.

Length is vendor-specific (MAX_ELEMENTS_ARRAYDIMENSION). See Constants of Array Lengths

BrowseName

STRING

The BrowseName is composed of a namespace index and a name. The String representation is of the format [ns:] BrowseName. The browse name may be prefixed by its namespace index. If the namespace prefix is omitted then namespace index 0 is used.

ContainsNoLoops

BOOL

Indicates that following forward references within a view will not cause a loop.

DataType

UANodeID

See UANodeID. The node id of the data type for the variable value.

Description

UALocalizedText

A localized description for the node.

DisplayName

UALocalizedText

A localized human readable name for the node.

EventNotifier

BYTE

This Attribute represents a bit mask that identifies whether the Object can be used to subscribe to Events and whether the history of Events is accessible and changeable.

Bit	Value	EventNotifier
	0x0	The Object does not produce events and has no event history. (SubscribeToEvents)
0	0x1	The Object produces event notifications.
1	0x2	Reserved. Must always be zero
2	0x4	The Object has an event history which may be read. (HistoryRead)
3	0x8	The Object has an event history which may be updated (HistoryWrite)
4
5
6
7

Executable

BOOL

Whether the method can be called.

Historizing

BOOL

Specifies whether the server is actively collecting historical data for the variable.

InverseName

STRING

The browse name for an inverse reference.

IsAbstract

BOOL

Indicates that a type node may not be instantiated.

MinimumSamplingInterval

TIME

Specifies (in ms) how fast the server can reasonably sample the value for changes.

NodeClass

UANodeClassMask

See UANodeClassMask. The base type of the node.

An enumeration identifying the NodeClass of a Node such as Object, Variable or Method.

NodeID

UANodeID

See UANodeID. The server unique identifier for the node.

Symmetric

BOOL

Indicates that forward and inverse references have the same meaning.

UserAccessLevel

BYTE

Contains the same information as the AccessLevel but takes user access rights into account.

Bit	Value	AccessLevel
	0x0	None
0	0x1	CurrentRead
1	0x2	CurrentWrite
2	0x4	HistoryRead
3	0x8	HistoryWrite
4
5
6
7

UserExecutable

BOOL

Whether the method can be called by the current user.

UserWriteMask

UDINT

Indicates which attributes are writable by the current user.

ValueRank

DINT

The number of dimensions in the value.

WriteMask

UDINT

Indicates which attributes are writable.

5.5.11 UANodeInformation

Note: Additional added Attributes from OPC UA (like DataTypeDefinition, RolePermissions, etc.) will not be reflected in UANodeInformation. Instead use UA_ReadList for this Attributes. The same is valid for the Attribute “Inverse Name (10)” when it needs to be a WSTRING instead of STRING.

UANodeInformation

DataType

Description

AccessLevel (17)

BYTE

A bit mask indicating whether the current value of the Value Attribute is readable and writable as well as whether the history of the value is readable and changeable.

Bit	Value	AccessLevel
	0x00	None
0	0x01	CurrentRead
1	0x02	CurrentWrite
2	0x04	HistoryRead
3	0x08	HistoryWrite
4	0x10	SemanticChange
5	0x20	StatusWrite
6	0x40	TimestampWrite
7

ArrayDimension (16)

ARRAY OFUDINT

The length for each dimension of an array value.

Length is vendor-specific (MAX_ELEMENTS_ARRAYDIMENSION). See Constants of Array Lengths

BrowseName (3)

UAQualifiedName

See UAQualifiedName.

ContainsNoLoops (11)

BOOL

Indicates that following forward references within a view will not cause a loop.

DataType (14)

UANodeID

See UANodeID. The node id of the data type for the variable value.

Description (5)

UALocalizedText

A localized description for the node.

DisplayName (4)

UALocalizedText

A localized human readable name for the node.

EventNotifier (12)

BYTE

This Attribute represents a bit mask that identifies whether the Object can be used to subscribe to Events and whether the history of Events is accessible and changeable.

Bit	Value	EventNotifier
	0x00	The Object does not produce events and has no event history. (SubscribeToEvents)
0	0x01	The Object produces event notifications.
1	0x02	Reserved. Must always be zero
2	0x04	The Object has an event history which may be read. (HistoryRead)
3	0x08	The Object has an event history which may be updated (HistoryWrite)
4
5
6
7

Executable (21)

BOOL

Whether the method can be called.

Historizing (20)

BOOL

Specifies whether the server is actively collecting historical data for the variable.

InverseName (10)

STRING

The browse name for an inverse reference.

IsAbstract (8)

BOOL

Indicates that a type node may not be instantiated.

MinimumSamplingInterval (19)

TIME

Specifies (in ms) how fast the server can reasonably sample the value for changes.

NodeClass (2)

UANodeClassMask

See UANodeClassMask. The base type of the node.

An enumeration identifying the NodeClass of a Node such as Object, Variable or Method.

Symmetric (9)

BOOL

Indicates that forward and inverse references have the same meaning.

UserAccessLevel (18)

BYTE

Contains the same information as the AccessLevel but takes user access rights into account.

Bit	Value	AccessLevel
	0x00	None
0	0x01	CurrentRead
1	0x02	CurrentWrite
2	0x04	HistoryRead
3	0x08	HistoryWrite
4	0x10	SemanticChange
5	0x20	StatusWrite
6	0x40	TimestampWrite
7

UserExecutable (22)

BOOL

Whether the method can be called by the current user.

UserWriteMask (7)

UDINT

Indicates which attributes are writable by the current user.

ValueRank (15)

DINT

The number of dimensions in the value.

WriteMask (6)

UDINT

Indicates which attributes are writable.

5.5.12 UAIndexRange

UAIndexRange	DataType	Description
StartIndex	UINT	Start index.
EndIndex	UINT	End index.

Note: IndexRange can be defined as follows: For each Dimension:

Start and EndIndex are to be assigned.
StartIndex must be smaller than EndIndex.
To access all the elements in a Dimension it’s a must to assign StartIndex and EndIndex depending on the number of total Elements in the Dimension.
A single element in a Dimension can be selected by specifying the same StartIndex and EndIndex.

5.5.13 UANodeAdditionalInfo

UANodeAdditionalInfo	DataType	Description
AttributeID	UAAttributeID	Selects the attribute to be accessed. The default AttributeID is UAAI_Value (13). See UAAttributeID
IndexRangeCount	UINT	Count of valid IndexRange specified. Vendorspecific.
IndexRange	ARRAY OFUAIndexRange	See UAIndexRange Length is vendor-specific (MAX_ELEMENTS_INDEXRANGE See Constants of Array Lengths

5.5.14 UAViewDescription

UAViewDescription	DataType	Description
ViewID	UANodeID	Node ID of the view to limit the browse. Empty for browsing the entire Address Space See UANodeID
TimeStamp	Vendor specific	If ‘0’ - any ViewID which matches should be used. Shall be DT or LDT. The recommendation for new implementation is to use LDT
Version	UDINT	If ‘0’ - any ViewID which matches should be used.

5.5.15 UABrowseDescription

UABrowseDescription	DataType	Description
StartingNodeID	UANodeID	Node ID of the starting node to browse. See UANodeID
Direction	UABrowseDirection	Browse direction forward, inverse, both. See UABrowseDirection
ReferenceTypeID	UANodeID	Node ID of the Reference Type the server should follow. See UANodeID Default value: HierachicalReferences
IncludeSubtypes	BOOL	Indicates if also subtypes of the Reference Type should be retuned Default: TRUE
NodeClass	UANodeClassMask	Filter on the Node Class of the retuned Nodes See UANodeClassMask
ResultMask	UABrowseResultMask	Selects which fields of the UAReferenceDescription are requested from the server. See UABrowseResultMask

5.5.16 UAReferenceDescription

UAReferenceDescription	DataType	Description
ReferenceTypeID	UANodeID	Node ID of the ReferenceType followed from the starting Node to the target Node. See UANodeID
IsForward	BOOL	Set if followed a forward Reference
NodeID	UAExpandedNodeID	Node ID of the target Node. This could also be a Node in another server. See UAExpandedNodeID
BrowseName	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. The qualified name of the target Node.
DisplayName	UALocalizedText	The localized name of the target Node. See UALocalizedText
NodeClass	UANodeClassMask	Node Class of the target Node. See UANodeClassMask
TypeDefinition	UAExpandedNodeID	Node ID of the Object or Variable type of the target Node. See UAExpandedNodeID

5.5.17 UAExpandedNodeID

UAExpandedNodeID	DataType	Description
ServerIndex	UDINT	The ServerIndex formatted as a base 10 number.
NamespaceURI	Vendor specific	Shall be STRING or WSTRING. The recommendation for new implementation is to use WSTRING. The NamespaceUri formatted as a string. Any reserved characters in the URI shall be replaced with a ‘%’ followed by its 8 bit ANSI value encoded as two hexadecimal digits (case insensitive). For example, the character ‘;’ would be replaced by ‘%3B’. The reserved characters are ‘;’ and ‘%’.
ID	UANodeID	An identifier for a node in the address space of an OPC UA Server. See UANodeID

5.5.18 UAHADataValue

UAHADataValue	DataType	Description
Value	Vendor specific	Vendor specific
StatusCode	UAHAUpdateStatusCode	See UAHAUpdateStatusCode
ServerTimeStamp	Vendor specific	Shall be DT or LDT. The recommendation for new implementation is to use LDT
SourceTimeStamp	Vendor specific	Shall be DT or LDT. The recommendation for new implementation is to use LDT

5.5.19 UAMonitoredVariables

UAMonitoredVariables	DataType	Description
Values	ARRAY OFVendor specific	Vendor specific. Array shall have the minimum length as UAMonitoringParameter QueueSize
TimeStamps	ARRAY OFVendor specific	Shall be DT or LDT. The recommendation for new implementation is to use LDT. It is expected, that the SourceTimeStamp from the server is returned. Optional – If exists it shall have the same length as the Values array.
NodeQualityIDs	ARRAY OFDWORD	Contains an error code for each element of the Values array. Optional – If exists it shall have the same length as the Values array. In case of “Overflow” Bit ‘7’ will be set if queue size is greater than 1. If this bit is set, not every detected change has been returned since the Server’s queue buffer for the MonitoredItem reached its limit and had to purge out data and the MinLostValueCount from UA_MonitoredItemAddList will be incremented by one (1).
NewValuesCount	UINT	Count of Values (Vendorspecific) which were updated starting from the lowest element of the Values.