| 摘要 |
PURPOSE:To switch a data line terminator to the DCE/DTE mode by switching automatically an input/output signal line of the data line terminator depending whether an input voltage of a reception signal voltage detecting circuit is within a prescribed voltage or at the outside of the range. CONSTITUTION:When a reception signal voltage at the input terminal of a receiver 11 is measured by a reception signal voltage detecting circuit 14, the reception signal voltage is <=-3V or >=+3V according to the specification. Thus, the circuit 14 detects it in such a case, its built-in relay 21 is inactivated and contacts 12, 13 are brought into the position shown in dotted lines. If the received signal voltage is between -3V-+3V by the decision of the circuit 14, the built-in relay 21 is activated and the contacts 12, 13 are thrown to the position shown in solid lines.
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