It becomes possible for a user to set a transmission or reception channel arbitrarily and easily. Each of equipment connected to an IEEE 1394 bus may include a register provided within a RAM 113 to thereby set a transmission or reception default channel. If channels used in the transmission and the reception are not set when the transmission is started, then default channel may be used. When equipment is set to a channel setting mode by operating an operation section 116, a control section 112 may display a channel setting picture on a display section 115. In this state, a user may select a set channel by operating an up-key 116a and a down-key 116b of the operation section 116. Thereafter, when a user operates a "YES" key 116c, the control section 112 may write a selected channel in the above-mentioned register, and ends a default channel setting operation. A user can set the transmission or reception channel arbitrarily and easily.