Modern SCADA systems are interconnected with one or more industrial network protocols such as DNP3, Modbus/TCP, Ethernet/IP, and IEC 60870-5-104(IEC 104). IEC 104 is a particularly important protocol because it is one of the network protocols used for Automatic Generation Control (AGC), which is the algorithm that maintains electric power balance across large geographical areas. In this work, we focus on an empirical study and observation of a real-world, large scale IEC 104 power network.