Building and managing intelligent digital substations is receiving much attention, worldwide. This paper proposes the collection of digital substation monitoring information by using DDS, which is a publication/subscription-based real-time communication protocol. The paper shows a network structure of digital substations for collecting monitoring information from each facility by applying DDS. The network structure has multiple search domains that separate power facilities in substations according to their functions. It also presents an object-to-object conversion relationship and DDS object identification system for changing existing IEC 61850 based systems to DDS-based systems. Applying the DDS to digital substations enables dynamic recognition/identification through the DDS discovery protocol and enables collecting only desired monitoring information. We configured an experimental network environment to measure the elapsed times for dynamic recognition and identification of an IED. The experimental network has two different domains. The experiment showed that real-time monitoring is possible. The HMI node can detect in less than 0.7sec when additional IEDs are installed in the substation. This method can be applied to a system where configuration of a power facility dynamically changes, such as a micro grid.