Data model

The IEC 61850 is the basic norm for different application-specializations (et.al. for the IEC 61400-25). Thats why all data- and object models for the standards that are based on this norm are equal. This data model is structured into five hierarchy levels. Thereby the corresponding standards provide the necessary Logical Nodes, Data Objects and Data Attributes. The user only needs to make sure that his Server is connected to the communication system and apply his own Logical Devices.

Data model 1:

Data model 2: Server

The first hierarchy level in the data model of the IEC 61850 or the IEC 61400-25 forms the server. The server offers a connection point for a device, whereby communication systems that are based on Ethernet can be linked. In this case TwinCAT would display such a server with the libraries that are included to the protocol on an Industrial PC or Embedded PC.

Data model 3: Logical Device

The Logical Devices form the second hierarchy level in the data model of the IEC 61850 and IEC 61400-25. This level separates a single physical device into several separate components, the so called Logical Devices. The advantage of this separation is that functions or objects that belong together will stand together because of their similarities. And they also can be switched into another operating mode. According to the device different Logical Nodes can be implemented out of the third hierarchy level.

Data model 4: Logical Node

The Logical Nodes form the third hierarchy level in the data model of the IEC 61850 or the IEC 61400-25. They represent the information of all the sub-functions that can occur in the digital station control technology and in wind energy plants. These are all the protective functions but also automation functions and functions to process measurement- and meter data. For all the normed Logical Nodes of the IEC 61850 and IEC 61400-25 there are defined identifiers that always consist of a shortcut with four letters. For example, the shortcut XSWI stands for Circuit Switch. A Logical Device can consist out of several of these nodes.

Data model 5: Data Object

A Logical Node can consist of several Data Objects that form the fourth hierarchy level of the IEC 61850 and IEC 61400-25 data model. Characteristic of this hierarchy level is, that data objects can be interlaced hierarchically. A data object can consist of several sub data objects before it will access on a basic- or complex data type in a Common Data Class (CDC).

Data model 6: Data Attribute

The lowest hierarchy level of the IEC 61850 and IEC 61400-25 are forming the data attributes. They display the detailed information or values of the data objects. Because the same scale of data attributes is defined for several data objects, the attributes of an object are combined into the so called Common Data Classes (CDC). Thereby the corresponding CDC is named for every data object. You can also say that the data objects are specializations of the CDC.