| 摘要 |
PURPOSE:To attain a transmission reception test and a data transmission reception by selecting either clocks extracted from a line with an external control signal or clocks which a communication control equipment generates inside the communication control equipment. CONSTITUTION:In case of connecting the communication control equipment 1 to a high speed digital communication network 4 through a digital terminating equipment 3, an earth is not supplied to a terminal 12 and a clock extraction circuit 6 executes the extraction of clocks from the data line from the digital terminating equipment which comes in from the terminal 11. And extracted clocks are supplied to a data reception circuit 9 and a data transmission circuit 10 through a clock switching circuit 8. By connecting a folded connector 15 to the output terminal of a high speed digital interface circuit 5 of the communication control equipment 1, the clocks from a clock generation circuit 7 are supplied to the data reception circuit 9 and the data transmission circuit 10. The data transmitted from the data transmission circuit 10 is received in the data reception circuit 9 through the folded connector 15 and by comparing the transmitted and received data, the confirmation of actions of the high speed digital interface circuit 5 can be possible. |
