The Table 4 defines the structure of an MDISBaseObjectType.

Table 4 - MDISBaseObjectType

Attribute

Value

BrowseName

MDISBaseObjectType

IsAbstract

True

References

Node Class

BrowseName

Data Type

TypeDefinition

ModellingRule

RW

Subtype of the BaseObjectType defined in OPC UA Part 5 – Information Model

HasComponent

Variable

Fault

Boolean

BaseDataVariableType

Mandatory

R

HasComponent

Variable

Warning

Boolean

BaseDataVariableType

Optional

R

HasComponent

Variable

Enabled

Boolean

BaseDataVariableType

Optional

R

HasProperty

Variable

TagId

String

PropertyType

Optional

R

HasComponent

Method

EnableDisable

See 5.2.3

Optional

HasComponent

Variable

FaultCode

UInt32

BaseDataVariableType

Optional

R

HasComponent

Variable

WarningCode

UInt32

BaseDataVariableType

Optional

R

HasSubtype

MDISDigitalInstrumentObjectType

HasSubtype

MDISDiscreteInstrumentObjectType

HasSubtype

MDISChokeObjectType

HasSubtype

MDISInstrumentObjectType

HasSubtype

MDISValveObjectType

HasSubtype

MDISAggregateObjectType

The RW column indicates if a Node of Variable NodeClass is readable, writeable or both readable and writeable. Other NodeClasses (Object, Method) do not support reading or writing and do not fill in this column.

By definition a Profile can require that an Optional item be provided, it cannot change the behaviour of an Object from what is described in this specification, which includes support for any Mandatory items. Profiles are described in section 12.

Fault – The status of the object, true if any fault exists.

Warning – The status of the object, true if any warnings exist. A warning does not require immediate operator action.

Enabled – This Variable is set as enabled (true) by default. When disabled the Object will not report any dynamic information other than a bad status code (Bad_InvalidState). It will still report configuration related information. For the MDISBaseObjectType the default is that only the Enabled flag, TagId and Enable method report values or perform functions. Subtypes of this ObjectType may describe additional requirements for disabled Objects.

TagId – The TagId is a unique equipment identifier. This is additional information that can be used to help identify the Variable associated with the instance of this type. This field is intended to be used to store the tag id from the P&ID

EnableDisable – This method allows a Client to disable or enable the Object.

FaultCode – An unsigned integer that describes a fault code(s), zero indicates no fault. The SPCS vendor will provide a definition of what the number means. It might be a bit field or a fault code.

WarningCode – An unsigned integer that describes a warning code(s), zero indicates no warning. The SPCS vendor will provide a definition of what the number means. It might be a bit field or an error code. If a WarningCode is provided then the Warning flag shall also be provided.