MDIS defines flags, general status information and other optional data collections that need to exist in a standard manner on MDIS Serversto allow for easier interoperation between Clientsand Servers. This information is provided via the MDISInformationObjectType.

The following section details the MDISInformationObjectType. This ObjectTypedefines a standard structure for organization of some basic Serverinformation. An instance of this object is required for all versions of MDIS Servers1.2 and greater. An instance of this ObjectTypeshall exist under the Objectsfolder on all OPC UA MDIS Servers. Clientsare required to be able to handle Serverswhich do not contain this object. The Clientshall assume any Serverthat does not contain an instance of this ObjectTypeis a version 1.1 or 1.0 MDIS Server.

image021.gif

Figure 19- MDISInformationObjectType

Table 7defines the structure of an MDISInformationObjectType.

Table 36– MDISInformationObjectType

Attribute

Value

BrowseName

MDISInformationObjectType

IsAbstract

False

References

Node Class

BrowseName

DataType

TypeDefinition

ModellingRule

RW

Subtype of the BaseObjectType (see Part 5 – Information Model)

HasComponent

Object

TimeSynchronization

MDISTimeSyncObjectType

Optional

HasComponent

Object

Signatures

FolderType

Optional

HasComponent

Variable

MDISVersion

MDISVersionDataType

MDISVersionVariableType

Mandatory

R

TimeSynchronization– this is an instance of the MDISTimeSynchronizationTypeobject, that allows a Clientto provide time information to a Serverif required. See 5.1.11for additional details.

Signaturesis a folder that contains all of the currently available signatures (profiles). The individual signature(s) are stored as FileObjectsand the format of the file(s) is vendor specific.

MDISVersionprovides information about the version of the MDIS specification that is implemented by the Server. This is provided to assist the Clientin determining what should be available and can also be used for automated testing of the Server.