| 摘要 |
PURPOSE:To prevent the occurrence of the deviation of an actual internal state of a slave station from the internal state of the slave station recognized with a master station by making the internal state of the slave station coincident forcedly with the content of station information when the master station receives a signal opposed from the content of the station information from the slave station. CONSTITUTION:Suppose that an error is caused by a signal sent from a slave station 3a on a CCS line and a closing signal 33a is arrived, a master station 2 closes the state of the relay line trunk 9a of the slave station 3a and sends a closing acknowledging signal 34 to the slave station 3a. Since the relay line trunk 9a is not actually closed, a line assignment requesting signal 31 may or may not be sent. When the signal 31, is received, the master station 2 discriminates that there is any error in the closing signal 33a or the line assignment requesting signal 31. Then the master station 2 makes the state of the relay line trunk 9a idle, uses the relay line trunk 9a as the object of line assignment control and sends a release acknowledging signal 35 to the slave station 3a. Thus, the deviation between the actual internal state of the slave station and the internal state of the slave station recognized by the master station is corrected automatically. |
