Patent ID: 8028112

Claim:
A communication method in a network system with a plurality of I/O devices, wherein at least one of the plurality of I/O devices has a device control means for controlling an input and an output of data to a device, and the at least one of the plurality of I/O devices comprises: a receiving means for receiving information including at least contents instructing an input time and an output time to said plurality of I/O device; a time tag generating means for generating a time tag indicative of said input and said output time included in said information received at said receiving means to output the same to said device control means; and a clock means for outputting a clock signal indicative of a present time, wherein said device control means is configured to compare said input time and said output time indicated by said time tag output from said time tag generating means with the present time indicated by said clock signal output from said clock means, and wherein said device control means is configured to output designated data to said device and input data from said device at said input and said output time; wherein the communication method in the network system is characterized in that, the plurality of I/O devices are connected in a daisy chain, the plurality of I/O devices are classified into a master node and a plurality of slave nodes, a terminal slave node of the plurality of slave nodes is an active node and other intermediate slave nodes of the plurality of slave nodes are passive nodes, and generation of a communication frame is performed at said active node only.