Where a SCADAPack E outstation is used to route DNP3 frames to different parts of a communications network, or the outstation needs to know the PSTN Number or IP Address of the SCADA Master (Geo SCADA Expert) or peer DNP3 devices, you will need to create and configure a DNP Route Table.
When the outstation receives or generates a DNP3 frame, it applies the following rules until the frame is either processed, sent or discarded:
- If the frame’s destination address is the SCADAPack E outstation’s DNP3 address, the frame is processed.
- If the frame’s destination address is a DNP3 broadcast address, the frame is processed.
- The DNP3 Route Table is searched, starting from the first entry and proceeding sequentially through the table until a Table End entry is found, for the first entry that matches the frame’s Source Port, Source Address, and Destination Address. Any off-line entries (Off Static, Off Dynamic, and Off Fixed) are skipped.
- If an on-line entry is found, the frame is sent via the corresponding Destination Port, using the corresponding Connection Number.
The Source Port and Source Address fields are ignored for any DNP3 frames that are generated by the outstation. In such a situation, the outstation will use the first route entry that matches the Destination Address of the frame.
- If the DNP3 Route Table is empty, and the frame was not received on the Master Port, the frame is sent via the Master Port (see Configure the Properties of the Individual Ports).
- The frame is discarded.
Further Information