IEC 62769-3-2021 pdf free download – Field device integration (FDI) – Part 3: Server.
An FDI Server provides information to FDI Clients through an Information Model(seeIEC 62769-5) as follows.
The Information Model includes information about Device Types and Device Instances.The information for a Device Instance includes offline data (engineering data), as well asonline data (values from the physical device).
The Information Model is created using information from FDl Packages.However，not allof the information in an FDl Package is reflected in the lnformation Model.
Referential integrity of the Information Model is maintained using information from FDlPackages.
FDI Packages can contain Attachments that contain device manuals and protocol-specificinformation (see IEC 62769-4). Those Attachments, including device manuals andprotocol-specific support files, are exposed via the Information Model.
FDI Device Packages contain information about device types_(seeIEC 62769-4). Each device type defined in a package is mapped to a distinct DeviceTypenode in the lnformation Model.
FDI Profile Packages are used to provide interaction with devices for which an FDl DevicePackage does not exist (see IEC 62769-4).
Multiple revisions of an FDI Package generate distinct DeviceType nodes in thelnformation Model (see lEC 62769-4).
FDl Packages contain digital signatures that allow an FDI Server to authenticate theircontents (see lEC 62769-4). An RFDI Server shall not use an FDl Package if the digitalsignature provided by the FDl Package is invalid.
An FDI Server shall verify the FDI Technology Version(see IEC 62769-1) of any FDl Packageit uses to ensure the FDl Package is compatible with the FDI Server.
The resulting functional structure of an FDl server is described in Annex A.
5 lnformation Model
5.1General
The FDl Server shall use the Device Definition of an FDl Package to maintain the InformationModel.
The Device Definition can contain conditional expressions. Conditional expressions are usedwhen a certain aspect of the Device Definition is not static but rather is dependent on thestate of the device. Whenever the online or offline values of a Device Instance are modified,the FDl Server shall re-evaluatethe relevant conditional expressions and modify thelnformation Model accordingly.
The evaluation of conditional expressions can invalidate variables in the Information Model.The FDI Server shall change the AccessLevel attribute of invalidated variables such that they are neither readable nor writable and the status of these variables shall be set to bad.Readand write service requests for invalidated variables shall return a failure.
The Device Definition can specify relationships between variables in a device. These relationships can impact the value of variables in the Information Model.
The FDI Server shall generate DataChange Notifications to any FDI Clients that are subscribing to Information Model elements that have changed.
FDI Packages provide Business Logic that is used by the FDI Server to maintain the integrity of the Information Model. The Business Logic specified in an FDI Package can invoke builtin functions that shall be implemented by the FDI Server. The builtin functions that shall be implemented by the FDI Server are specified in IEC 61804-5.
5.2 Online/Offline Overview
5.2.1 The Information Model maintained by the FDI Server contains online and offline values. The online values reflect values in a physical component/device. The offline values reflect values stored in a configuration database.IEC 62769-3 pdf download.