The communication between the control center (Master Terminal Unit, MTU) and all remote stations (Remote Terminal Units, RTUs) in the dataset is based on the 60870-5-104 (IEC 104) protocol. Over this protocol, the MTU can send commands (set points) to the RTUs to influence their behavior. Similarly, the RTUs send periodic and spontaneous measurements to inform the MTU on the current grid state.
This exchange of commands and measurements used data points, each representing a specific value for a specific grid element (e.g., a generator). In the IEC 104 protocol, each data point is a so-called information object, identified by the unique common address (COA) of the responsible station and the station-specific information object address (IOA) of the information object. Hence, on the communication level, each data point is conceptually addressable as $COA.$IOA. Following the Wattson notation, we call this unique address the data point identifier.
To allow the grid operator to interpret the measurements associated with these data point identifiers, a mapping between data points and attributes of grid elements (so-called grid values) is necessary. Grid values are identified by their respective grid value identifier, which includes the grid element identifier (combining the element’s type and ID, e.g., bus.0), the context (mainly CONFIGURATION for set points and MEASUREMENT measurements), and the attribute’s name (e.g., voltage). Hence, the grid value with identifier bus.0.MEASUREMENT.voltage represents the voltage measurement at bus 0. In the 01-Basic scenario, this is provided by RTU 101 at information object address 10010, i.e., the respective data point has the data point identifier 101.10010. All data point identifiers are specific to their respective scenario! The respective mapping is included for all dataset scenarios and topologies and directly applied to all IPAL transcripts for ease of use.
The following table summarizes common grid values that are included in the dataset transcriptions.