Patent ID: 7583692

Claim:
A communications network comprising: at least two network nodes, between which data can be transmitted via a transmission medium; a communications schedule for allotting time slots to the network nodes for access to the transmission medium, wherein the network nodes each comprises at least one communication controller with a first scheduler for controlling access by the network nodes to the communications schedule; and at least one bus guardian with a second scheduler for monitoring accesses by the network nodes to the transmission medium according to a monitoring schedule, wherein the communication controller comprises means for generating a local, independent clock signal and a global clock signal, which is determined by at least one parameter of the communications system; and a divider, wherein the divider receives the local, independent clock signal and divides a frequency of the local, independent clock signal to output a bus guardian tick signal to the bus guardian, wherein the communication controller supplies the global clock signal to the bus guardian, and wherein the bus guardian monitors the global clock signal by means of the bus guardian tick signal, and wherein means for providing the global clock signal is provided both to the first schedulers of the communication controllers to clock the first schedulers, and is provided to the second scheduler of the bus guardian to clock the second scheduler of the bus guardian.