| 摘要 |
PURPOSE:To shorten the time for testing a multiple function telephone set by connecting plural user information channels in series to make test signals sent out from a test signal transmitting circuit pass through plural user information channels in order and return to a test signal detecting circuit. CONSTITUTION:Test signals outputted from a test signal transmitting circuit 5 of a test trunk 4 pass through a down circuit of a user information channel 3a, and after turning back at a digital multiple function telephone set 2, pass through a user information channel 3b via a time-division switch network 1 and return to a test signal detecting circuit 6. This means that transmitting functions are tested under the state each user information channels 3a and 3b are connected in series. In the case where the number of user information channels is N generally, the time for testing can be shortened furthermore. |
