4. Configuration
159
The implementation of the IEC 61850 data structure in MasterTool Xtorm IEC 61131-3
programming environment is achieved by POUs of Function Block type. The Logical Devices,
Logical Nodes and Objects are represented by a Function Block, while Attributes become symbolic
variables of elementary types according to IEC 61131-3. All these data are declared in a global
variable list (GVL) automatically created by MasterTool Xtorm tool and are stored in the "IEC61850
Generated POUs" located in the project tree. The Figure 4-39 shows an example of POUs generated
from an IEC 61850 configuration:
Figure 4-39. Data Model Implementation
For each instance of a Logical Node present in the IEC 61850 configuration, it is created a Function
Block corresponding type (stored in the "Logical Nodes" folder). This is necessary because each
Logical Node can be customized by adding Objects and optional attributes.
As mentioned earlier, each Attribute becomes a symbolic variable in the IEC 61131-3 programming
environment. The Table 4-113 shows the matching between the basic data types of IEC 61850 and
the elementary data types of IEC 61131-3:
IEC 61850 Basic Type
IEC 61131-3 Basic Type
BOOLEAN
BOOL
INT8
SINT
INT16
INT
INT32
DINT
INT8U
USINT
INT16U
UINT
INT32U
UDINT
FLOAT32
REAL
FLOAT64
LREAL
ENUMERATED
INT
CODED ENUM
INT
OCTET STRINGnn
VISIBLE STRINGnn
UNICODE STRINGnn
STRING(nn)
Table 4-113. Correspondence of data types IEC 61850 vs IEC 61131-3