Double ring network system and communication control method thereof, and transmission station, and program for transmission stations

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:nfor 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; anda 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; furthera 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; anda 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; furtherfor 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; andfor 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, whereinthey 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.

A double ring network system including a plurality of transmission stations having any one thereof as a base station, and each respectively connected by a dual transmission line composed of a first communication line and a second communication line, the respective transmission station comprising a first communication port for receiving at one end side thereof left-handed information from the base station and outputting right-handed input information from the base station or information generated at this station in a right-handed direction from the one end side, and a second communication port for receiving at another end side thereof right-handed input information from the base station and outputting the left-handed information or information generated at this station in a left-handed direction from the other end side, to perform bi-directional communications in between, characterized in thatnthe base station comprises, for an initial phase of startup,initialization frame transmitting means for transmitting right-handed and left-handed initializing first frames containing information having a source as the base station and a destination of transmission station designated, simultaneously from the first communication port and the second communication port, andthe other stations comprise, for the initial phase of startup,initialization frame reception permitting means for permitting reception of information from the first communication port and the second communication port,first-come determining means for determining, when the first frames are received at the first communication port and the second communication port, the communication port having first-received said first frame,own station position identifying means for determining, when the right-handed and left-handed first frames having this station as a destination are received the right-handed at the first station and the left-handed at the second station, respectively, the station being positioned at a left-handed end or a right-handed end, whichever is in accordance with line lengths from the base station to this station and identification information of respective stations the right-handed and left-handed routed through as contained in the first frames, and outputting a terminal station setting signal to have set if it stands as a terminal station on either hand,first terminal station deciding means for operating with the terminal station setting signal output, for a result of the first-come determination that the first communication port has first received the right-handed first frame, to set the own station to be a terminal station mode at a left-hand end from the base station, transmit the left-handed first frame the second communication port has received temporarily to a left-hand adjacent station, and thereafter, stop sending information from the second communication port, andsecond terminal station deciding means for operating with the terminal station setting signal output, for a result of the first-come determination that the second communication port has first received the first frame, and the first communication port has received the left-handed first frame from a right-hand adjacent station, to set the own station to be a terminal station mode at a right-hand end from the base station, and stop sending information from the first communication port.

A transmission station for double ring network systems including a plurality of transmission stations having any one thereof as a base station, and each respectively connected by a dual transmission line composed of a first communication line and a second communication line, the respective transmission station comprising a first communication port for receiving at one end side thereof left-handed information from the base station and outputting right-handed input information from the base station or information generated at this station in a right-handed direction from the one end side, and a second communication port for receiving at another end side thereof right-handed input information from the base station and outputting the left-handed information or information generated at this station in a left-handed direction from the other end side, to perform bi-directional communications in between, characterized in thatnthe base station comprises, for an initial phase of startup,initialization frame transmitting means for transmitting right-handed and left-handed initializing first frames containing information having a source as the base station and a destination of transmission station designated, simultaneously from the first communication port and the second communication port, andthe other stations comprise, for the initial phase of startup,initialization frame reception permitting means for permitting reception of information from the first communication port and the second communication port,first-come determining means for determining, when the first frames are received at the first communication port and the second communication port, the communication port having first-received said first frame,own station position identifying means for determining, when the right-handed and left-handed first frames having this station as a destination are received the right-handed at the first station and the left-handed at the second station, respectively, the station being positioned at a left-handed end or a right-handed end, whichever is in accordance with line lengths from the base station to this station and identification information of respective stations the right-handed and left-handed routed through as contained in the first frames, and outputting a terminal station setting signal to have set if it stands as a terminal station on either hand,first terminal station deciding means for operating with the terminal station setting signal output, for a result of the first-come determination that the first communication port has first received the right-handed first frame, to set the own station to be a terminal station mode at a left-hand end from the base station, transmit the left-handed first frame the second communication port has received temporarily to a left-hand adjacent station, and thereafter, stop sending information from the second communication port, andsecond terminal station deciding means for operating with the terminal station setting signal output, for a result of the first-come determination that the second communication port has first received the first frame, and the first communication port has received the left-handed first frame from a right-hand adjacent station, to set the own station to be a terminal station mode at a right-hand end from the base station, and stop sending information from the first communication port.

A non-transitory computer readable medium storing a program for control of communications for double ring network systems including a plurality of transmission stations having any one thereof as a base station, and each respectively connected by a dual transmission line composed of a first communication line and a second communication line, whereinna respective transmission station comprising a first communication port for receiving at one end side thereof left-handed information from the base station and outputting right-handed input information from the base station or information generated at this station in a right-handed direction from the ore end side, and a second communication port for receiving at another end side thereof right-handed input information from the base station and outputting the left-handed information or information generated at this station from the other end side, to perform bi-directional communications in between, whereina respective transmission station comprising a first communication port for receiving at one end side thereof left-handed information from the base station and outputting right-handed input information from the base station or information generated at this station in a right-handed direction from the one end side, and a second communication port for receiving at another end side thereof right-handed input information from the base station and outputting the left-handed information or information generated at this station in a left-handed direction from the other end side, to perform bi-directional communications in between,characterized in that the program for control of communications for double ring network systems implements functionsfor the base station, for an initial phase of startup, asinitialization frame transmitting means for transmitting right-handed and left-handed initializing first frames containing information having a source as the base station and a destination of transmission station designated, simultaneously from the first communication port and the second communication port, andfor the other stations, for the initial phase of startup, asinitialization frame reception permitting means for permitting reception of information from the first communication port and the second communication port,first-come determining means for determining, when the first frames are received at the first communication port and the second communication port, the communication port having first-received said first frame,own station position identifying means for determining, when the right-handed and left-handed first frames having this station as a destination are received the right-handed at the first station and the left-handed at the second station, respectively, the station being positioned at a left-handed end or a right-handed end, whichever is in accordance with line lengths from the base station to this station and identification information of respective stations the right-handed and left-handed routed through as contained in the first frames, and outputting a terminal station setting signal to have set if it stands as a terminal station on either hand,first terminal station deciding means for operating with the terminal station setting signal output, for a result of the first-come determination that the first communication port has first received the right-handed first frame, to set the own station to be a terminal station mode at a left-hand end from the base station, transmit the left-handed first frame the second communication port has received temporarily to a left-hand adjacent station, and thereafter, stop sending information from the second communication port, andsecond terminal station deciding means for operating with the terminal station setting signal output, for a result of the first-come determination that the second communication port has first received the first frame, and the first communication port has received the left-handed first frame from a right-hand adjacent station, to set the own station to be a terminal station mode at a right-hand end from the base station, and stop sending information from the first communication port.