摘要 |
A network effectively providing multi-node communication of audio information has a number of node units (20, 40) interconnected to enable any node unit to send audio and/or control information to any other node unit. The connecting cable (6) interconnecting the node units (20, 40) has both transmit and receive pairs so that there is no requirement to form physical rings with return cables, but the node units (20, 40) are interconnected to form logical rings (RINGS 1-5). Because each node unit at the end of a ring has only a single one of its connection parts connected to other node units of that ring, each node unit (20, 40) on being connected into the network is able to identify whether it is an end, or a middle, node unit, such that, on formation of the network, the ring structure is configured automatically. Furthermore, one of the node units provides the reference clock for the whole of the network, and the remaining node units (20, 40) synchronise themselves to the clock source node unit automatically on set up. For example, one node unit (HUB 2) may be designated as the clock master unit on initialisation. The node unit (HUB 2) is established first of all as the clock master of a ring (RING 1), and thereafter, the rings communicate to set that node unit (HUB 2) as the clock master for the network. |