| 摘要 |
PURPOSE:To test simply a data access unit (DAU) installed decentralizingly by utilizing a folded loop circuit incorporated in the DAU and transmitting a test data from a data subscriber line of an exchange. CONSTITUTION:An output terminal to a data terminal equipment DTE of an interface INT in the DAU is connected to an input terminal from the DTE so as to form a folded loop circuit and connected to a data subscriber circuit DLC via a main distribution fitting MDF of an exchange side. Then a test data is set to a transmission register REGt of the DLC, and this data is transmitted via a transmission selector SELt, a transmission section T and a transmission section L. The DAU receives the data, folded by the folded loop circuit formed in the INT and the test data is transmitted to the EX side from a LINE-T line termination section. The DLC stores it to a reception register REGr via a reception R and a reception selector SELr, the test data stored in the REGt and the data of the REGr are compared so as to decide the propriety of the DAU. |
