Abstract - In this paper, we propose a monitoring tool for detection of middleware errors in Smart DDS (Data Distribution Service) in a combat system. Trap combat systems are based on Smart DDS and include various equipment and applications such as monitoring tools, search radar, and communication equipment. Due to this configuration, if there is a communication problem in the exhibition situation, all equipment can not respond quickly to the battle. In this paper, we analyze the problems in middleware by utilizing Smart DDS's Data-Centric Publish-Subscribe (DCPS) and Real-Time Publish-Subscribe (RTPS) layers to expedite communication problems. Existing Smart DDS application tools exist but are not suitable for urgent display situations because there is an unnecessary discovery process for debugging. The proposed tool utilizes the discovery process of the DDS and the interface of the DCPS. As a result of the simulation, the proposed monitoring tool can reduce the time required for problem detection and provide data for error resolution as compared with existing debugging tools, thereby improving the recovery performance of the trap fighting system.