| 摘要 |
PURPOSE:To increase the allowable data transfer quantity of a dual communication line and make a normal data transfer possible even when the communication line is faulty, by providing a data type discriminating means and specific switching means and processing means in each of the transmission end and the receiving end. CONSTITUTION:In the data transfer system where data is transferred through a dual communication line 3 consisting of two communication lines 31 and 32 where data is communicated in two directions, discriminating circuits 61 and 71 which discriminate the type of transfer data are provided in the transmitting end and the receiving end of data, repsectively. Switching circuits 63 and 73, which switch the communication directions of two communication lines 31 and 32 to the same direction in accordance with the type discriminated by circuits 61 and 71, and processing circuits 64 and 74 which convert data, which is transferred in parallel through two communication lines 31 and 32 whose directions are set by switching of circuits 63 and 73, in the transmitting end and convert this data reversely in the receiving end are provided. For example, these circuits 61-74 are provided in data transfer controllers 6 and 7, and data transfer is performed through two-way MODEMs 40 and 50 in accordance with the data type. |
