Today, new synchrotron-radiation facilities have been built around the world. One of these facilities, RIKEN XFEL project in Japan, is characterized by its location beside existing facility, SPring-8. Using X rays from two facilities in coincidence, new scientific applications are expected such as pump-and-probe experiments, and so on. We also plan to use linac of the XFEL as another injector to the SPring-8. By benefiting from combined application with two facilities, it is necessary to integrate two control systems. Important point of the integration is combination and segregation of two facilities. For combined applications, two control systems should be treated as one facility. On the other hand, when two facilities are operated separately, two control systems should be independent each other, and one system must not be affected by any trouble of another system. To archive the point, we physically segregate control system into two networks using firewall. Since control architecture in SPring-8 is database oriented, two systems can be coupled with synchronization of database for combined applications. We show the concept and upgrade status of new network and control system.