Patent ID: 8018867

Claim:
A network system comprising: a monitored node which is connected to a network for isochronous transfer and asynchronous transfer and has a utility function; a monitoring node which monitors an operating state of the monitored node; and a further node which is different from the monitored node and the monitoring node and provides a cycle start packet to the network, wherein the monitored node cyclically transmits a command representative of a normal operating state thereof to the monitoring node in one of isochronous channels in a time cycle of the network that differs from an isochronous channel used for the utility function in the time cycle, and when the monitoring node determines non-reception of the command representative of the normal operating state from the monitored node, the monitoring node transmits, to the monitored node, a real-time command to execute abnormality response processing, in one of the isochronous channels, and the monitored node executes the abnormality response processing in response to reception of the real-time command.