Patent ID: 7349329

Claim:
A network system comprising: a plurality of nodes arranged on a bidirectional ring network, each node comprising: a buffer control unit, a controller; and a data transmitter-receiver having two transmit/receive units, one transmit/receive unit for a normal direction and another transmit/receive unit for a reverse direction, each transmit/receive unit having an intermediate buffer between an input buffer and an output buffer; and a nonredundant transmission line formed in a closed loop for connecting every pair of adjacent nodes of the ring network, wherein data is transmittable bidirectionally between the nodes through the transmission line; and wherein operation modes of the nodes include a data communication verification mode in which the controller controls the data transmitter-receiver and the buffer control unit to selectively activate and deactivate the buffers of each transmit/receive unit to transmit packets of data at a series of definite times in normal and reverse directions alternately to determine if each node receives every packet of data from the nodes.