| 摘要 |
<p>PURPOSE:To attain efficient data communication without error by sending a rise-up test command when the state of line is good, and increasing the line state thereby maintaining the data communication. CONSTITUTION:When the line state is excellent and the line speed of the data during communication is increased, a protocol control section 3 sends the rise-up command at the line speed during communication at present to the receiver side. In detecting the rise-up command, a protocol processing section 4 sends a rise-up acknowledge to the caller side and informs it to a control section 8 that the line speed is to be increased, and the control section 8 controls a modulator-demodulator section 6 to increase the line speed. In detecting the rise-up reply from the receiver side, the processing section 3 informs the increase of the line speed to the control section 7, which controls the modulator- demodulator section 5 to increase the line speed. Thus, after the line speed is increased for both the sender/receiver sides, the link of communication protocol is established between the processing sections 3 and 4.</p> |
