Data communication method, communication frame generating method, and medium on which program for carrying out the methods are recorded

摘要

A control portion A transmits only a transmission right to a control portion B. The control portion B receives the transmission right sent from the control portion A, obtains transmission-requested data B from a utilization portion B, and then transmits it with the transmission right to the control portion A. The control portion A receives the data B and transmission right transmitted from the control portion B. If the control portion A is receiving a transmission request for data A from the utilization portion A at this time, it first obtains the transmission-requested data A from the utilization portion A and transmits it to the control portion B together with the transmission right. After transmitting the data A, the control portion A transfers the data B received from the control portion B to the utilization portion A.