| 摘要 |
PURPOSE:To decrease the quantity of the loaded data required at recovery by multiplexing a data base system which can work by itself in the form of a rough connection using a communication circuit and therefore preventing the fault of another system from affecting its own system. CONSTITUTION:A data intra-house circuit terminating device DCE1 performs the electrical interface conversion between a data packet network PSDN and a terminal interface switching device SEL2. In case a data base system DES3 has a fault while a switch SW is kept OFF in the SEL2, this SW is turned on. The contents of a file memory FM set in a DBS 4 are coincident with the contents of an FM contained in a DBS 3 as long as the difference data on a portable replacement type data memory medium (FD/MT) is added to the FM capacity of the DBS 4 at that time point. |
