Patent ID: 7280550

Claim:
A node for a ring topology network having a plurality of ring segments, comprising: a first selectable configuration wherein the node comprises means for measuring a transmission time, diff 0 , of a first clock signal transmitted by the node in a first direction around the network and propagated by each slave node on the network; and a second selectable configuration wherein the node comprises means for determining a propagation delay, delay i , for a ring segment associated with each slave node the means for determining comprising: means for transmitting a second clock signal in the first direction to a selected slave node, i; means for transmitting a third clock signal in a second direction, opposite the first direction, to the selected slave node i, whereby the selected slave node I measures the difference, diff i , in the arrival times of the second and third clock signals; means for receiving a signal representative of the difference, diff i , from the selected slave node i; means for determining the propagation delay, delay i , for a ring segment associated with the selected slave node i; means transmitting a signal representative of the propagation delay, delay i , to the selected slave node i in response to which the selected slave node i adjusts a clock signal generator to compensate for the propagation delay, delay i .