A transmission frame structure for use in a control communication network allows all
process control stations contained in the control communication network to share monitoring / control information received from a field communication network or an information communication network, and properly copes with faulty operations of channels (i.e., ring-shaped lines) or
process control stations for use in the control communication network. The transmission frame structure of a control communication network for use in a nuclear-power-
plant distributed control system which broadcasts data received from a node having transmission authority to all nodes via a bypass line, and allows a ring accelerator to detour the data and to isolate an erroneous
station from normal stations, includes a transmission frame. The transmission frame includes: a destination address for performing the
broadcasting operation; a
source address for recording a source node address (ID) therein; a type / length field for classifying frames into a
control data frame and a
network management event frame; a
network management (NM_TYPE) field which is valid only when it is designated by type / length field, and performs different roles according to
network management event frame types; a Seq&Ver field for including the number of transmissions of a data frame and frame
upgrade version information; a NS_ID field for recording number information of a node equal to the next token reception node, and being used when one
station transmits a token to the next
station; a
data field having a predetermined
maximum size of 1 kbyte, for including not only general control information according to a value of the type / length field, but also 7 event frames such as a token frame; and a CRC (Cyclic Redundancy Code) field for inspecting the presence or absence of a CRC error, whereby the transmission frame operates the communication network, solves a malfunction or error of the communication network, and recovers the communication network.