Patent ID: 9100211
Filing Date: 2015-08-04
Classification: H04L

Abstract:
1. A communication control method for double ring networks including a plurality of transmission stations, each configured with a pair of communication ports for communications to be implemented bi-directionally, and mutually connected by said pairs of communication ports in a ring form through a transmission line to implement intercommunications between the transmission stations, comprising: for one transmission station in said plurality of transmission stations as a base transmission station, a step of sending initialization frames, which are periodically initialization-instructing transmission frames, in both directions; for a respective transmission station receiving and detecting said initialization frames, a step of turning repeat of transmission frame from a communication port on the received side to a communication port on the other side, from a prohibiting state to a permitting state; and a step of permitting reception and take-in of transmission frame thereafter at the communication port on the received side, and sending an initialization frame as a responding acknowledgment at the communication port side, as a response for reception acknowledgment; further a step of responding to reception and detection, as following the sending the initialization frame, of a said above-noted responding acknowledgment initialization frame from an adjacent transmission station in a repeating direction from said communication port having first received an initialization frame to the other communication port, by turning repeat of transmission frame from a communication port on the received side to a communication port on the other side, from a prohibiting state to a permitting state; and a step of permitting reception and take-in of transmission frame thereafter at the communication port on the received side, whereby at this transmission station thereafter reception and take-in of transmission frames to be received at communications ports on bi-directional sides and repeat to the other sides are enabled; further for a transmission station in a position to receive said initialization frames at communication ports on both sides, and a transmission station in a position adjacent to said transmission station, as they are determined in accordance with a total number of said transmission stations, and a total length of the transmission line connecting said transmission stations with each other, a step of having a transmission frame sent from one said transmission station's communication port and received at said other transmission station's opposing communication port, detected at this transmission station; and for said transmission frame to be responded in accordance with information contained, setting repeat from the received communication port to the other communication port to a permitting state, wherein they are configured as terminal stations also for reception and take-in to be prohibited, whereby at a respective one of these terminal stations no transmission frame received from the other terminal station is repeated to send to subsequent transmission stations in a repeating direction, and transmission frames sent from respective transmission stations are kept from circulating in the double ring networks, wherein for one transmission station in said plurality of transmission stations as a base transmission station, a step of sending initialization frames, which are periodically initialization-instructing transmission frames, in both directions: for a transmission station adjacent to said transmission station having received and detected said initialization frames, a step of turning repeat of transmission frame from a communication port on the received side to a communication port on the other side, from a prohibiting state to a permitting state; and a step of permitting reception and take-in of transmission frame thereafter at the communication port on the as-having-received side; and a step of sending initialization frames as a responding acknowledgment addressing a source address of said initialization frame as a destination, in both directions, as a response for reception acknowledgment; further a step of responding to reception and detection, as following the sending the initialization frame, of a said responding acknowledgment initialization frame of an adjacent transmission station addressing own station, from said adjacent transmission station in a repeating direction from said communication port having first received an initialization frame to the other communication port, by turning repeat of transmission frame from a communication port on the received side to a communication port on the other side, from a prohibiting state to a permitting state, wherein reception and take-in of transmission frame are permitted thereafter at the communication port on that as-having-received side, whereby at this transmission station thereafter reception and take-in of transmission frames to be received at communications ports on both sides and repeat to the other sides are enabled, and beginning from said transmission station as a base having sent initialization frames in both directions, sequentially on respective transmission stations in positions in both directions, reception of an initialization frame is responded by again sending initialization frames at communications ports on both sides, a step of thereby determining in accordance with a total number of said transmission stations, and a total length of the transmission line connecting said transmission stations with each other, a transmission station in a position to receive initialization frames at communication ports on both sides, and a transmission station in a position adjacent to said transmission station; for a respective one of which a step of having a transmission frame sent from one said transmission station's communication port and received at said other transmission station's opposing communication port, detected at this transmission station, and for said transmission frame to be responded in accordance with information contained, setting repeat from the received communication port to the other communication port to a permitting state, wherein they are configured as terminal stations also for reception and take-in to be prohibited, whereby at a respective one of these terminal stations no transmission frame received from the other terminal station is repeated to send to subsequent transmission stations in a repeating direction, and transmission frames sent from respective transmission stations are kept from circulating in the double ring networks.