PURPOSE: To enable a quick and easy operation by providing a mode setting means for setting a retrieval mode and a display control means for displaying an identification code and connecting with a corresponding device to be monitored when an identification code specifying operation is performed.

CONSTITUTION: A remote system console 140 collects log data from digital switchboards 11a-11d to be monitored through a public line network 15 and the CPU 410 of the console 140 displays a function menu on a display 14c. When 'automatic line connection' within the function menu is specified by operating a keyboard 14d by the supervisor of the console 140 in the state, an automatic line connection picture is displayed on the display 14c. A site retrieval mode selection picture is present in the picture and the various kinds of display such as site numbers and ports are displayed. A desired device to be monitored is specified by designating the site signal. Then, the CPU 410 is connected through the network 15 to a controller 120 and then is connected to the target device to be monitored.