| 摘要 |
PURPOSE:To improve the overall system reliability by switching automatically a POS loop connected to a file control part to a normal file control part in case said file control part has a trouble. CONSTITUTION:Two file control parts 11a and 11b are provided. If the part 11a, for example, has a trouble and transmits no control signal any more, a trouble detecting circuit 16a works and delivers a trouble detecting signal to actuate a switch control circuit 17. Thus a switching circuit 15 performs the switch control so that a POS loop 12a connected to the faulty part 11a and the other POS loop 12b are connected to the normal part 11b in the form of closed loops. |
