Patent ID: 8724640

Claim:
A method for operating a distributed communications network with a plurality of network nodes, each network node being assigned an identity value from a range of identity values and an address to communicate with other network nodes, and each network node being responsible for a sub-range of identity values from the range, comprising: managing a table by each operational network node, wherein the table is a double-key hash table containing an entry for each operational network node in the communications network, the entry comprising the identity value and the address of the respective network node, wherein the identity values equal hash values, and wherein the double-key hash table further comprises an engineering component identity for each network node, each engineering component identity corresponding to an engineering component or a part of an engineering component of an engineering system; sending regularly activity messages by each operational network node to the other network nodes of the communications network, the activity messages each containing the identity value, the address of the respective network node and the engineering component identity; and synchronizing the table by each operational network node, upon receiving an activity message, with the contents of the activity message, monitoring the network nodes in order to detect when a network node becomes inactive, the monitoring being performed via a monitoring node which is assigned to the network node, wherein the monitoring node monitors whether the network node is transmitting activity messages, wherein, when the network node is no longer transmitting activity messages, the monitoring node transmits a deactivation message to all the other network nodes, the deactivation message containing the identity value of the network node, wherein the inactive network node no longer sends activity messages, and wherein a network node receiving a deactivation message sets the status field of the entry of the network node given by the identity value in the deactivation message to inactive.