| 摘要 |
PURPOSE:To change the communication speed without stopping data transmission by providing a data flow control section to a communication controller, switching a communication speed of an MODEM of a terminal device side with deceleration and restoring the speed to the original communication speed after the restoration of the rater of operation. CONSTITUTION:The communication controller 2 is provided with a data flow control section 9, a flow control command signal 8' is transmitted to the control section 9 when the rate of use reaches a ference value from a rate of use supervisory section 8 supervising the use rate 5' of a transmission/reception buffer during the data processing, and a communication speed changeover command signal 9' is transmitted to an MODEM3A at a terminal device. Then the communication speed of the MODEM at the terminal device is switched into 1/2 or 1/4 of the normal speed by using the signal 9' and continued, and when the rate of use is restored, the speed is restored the original communication speed. |
