JP5195023B2 - Communication apparatus and communication method - Google Patents

Description

  The present invention relates to a data communication system conversion technique.

  The access control method in the network can be said to be a method for solving the collision (collision) of data on the network media. In addition, various standards or specifications that define access control methods define how to control electrical signals that flow through a transmission medium.

  The above-mentioned collision is a data collision occurring in the network. For example, in the case of the half-duplex transmission method, when data is simultaneously transmitted from different nodes on the same network, the data collide on the transmission path and the data is broken.

  The above-described access control method is generally realized by a MAC (Media Access Control) layer and a physical layer of the data link layer.

The above-described collision will be described with reference to FIG. In the network configuration of FIG. 11, the network is terminated by termination resistors T ₁ and T ₂ , and terminals P _{A to} P _E are connected.

Transmission state S _t11 at terminal P _A from the terminal P _E of the network of FIG. 11, when the terminal P _E thus transmitting the transmission terminal P _C at the same time, collides with the next transmission state S _t12 (collision occurs) Therefore, these transmitted data are corrupted. One method for avoiding such data collapse due to collision is the CSMA / CD method. In addition, a range where collision may occur on the network is referred to as a collision domain (for example, a collision domain D _{C in} FIG. 11).

  The access control method in Ethernet (registered trademark) related to (or included in) the Internet protocol used in the communication method of the current remote monitoring and control device is “IEEE (Institut of Electrical and Electronic Engineers) 802.3 CSMA / CD”. (Carrier Sense Multiple Access with Collision Detection) ”. Similarly, the access control method in the token ring method and the FDDI (Fiber Distributed Data Interface) method used in the communication method of the remote monitoring control device is defined by “IEEE 802.5 token passing”.

  The FDDI method is an extended method of the token ring method, and realizes a transmission rate of 100 Mbps (megabit per second) using a double ring optical fiber by using the token passing method. In the general FDDI system, a communication cable is laid with a double structure of a primary ring and a secondary ring. In normal communication, a primary ring is used, and when the primary ring breaks down or the like, communication can be prevented by turning back to the secondary ring side so as to avoid that portion.

  Hereinafter, the CSMA / CD method and the token passing method of the access control method will be described.

  The CSMA / CD method is called a collision detection type carrier detection multiple access method, and is a method often used in a network such as a general LAN (Local Area Network). The feature of this CSMA / CD system is a mechanism that makes it safe even if a collision occurs, and not a mechanism that prevents a collision. The CSMA / CD system is premised on a bus topology in which terminals such as a plurality of computers are connected to one coaxial cable.

Information transmission in the CSMA / CD system is performed in the following procedure.
(Procedure A1) Carrier Sense (Carrier Sense): A terminal that transmits data detects whether or not a carrier wave already exists before transmission.
(Procedure A2) Multiple Access: Multiple cables share a single cable.
(Procedure A3) Collision Detection: When data is flowing simultaneously, collision occurs in the cable. When the collision is detected, transmission is stopped, a random time is waited, and transmission is performed again. This process is called back-off, and the random waiting time is called back-off time.

  The token passing method is an access control method used in a token ring type topology. In the token ring type, as its name suggests, several terminals are connected in the ring type. In the token passing method, a frame called a token is passed from terminal to terminal, just like a bucket relay, and transmitted to a target terminal. This method does not cause a collision because there is only one token on the network. Therefore, it is not necessary to detect a collision unlike the CSMA / CD method.

An example of an information transmission procedure in this token passing system will be described with reference to FIG. The network in FIG. 12 is a token ring type, and terminals P _{A to} P _E are connected to the network. Further, in FIG. 12 is assumed to transfer data from the terminal P _C to the terminal P _E.
(Procedure B1) When data is not transmitted, an empty token is circulating on the network (transmission state _St21 ). This empty token is called a free token.
(Step B2) free token terminal P _C which has received the (transmits) flow to the transmission line also put the contents to be transmitted to the token (Network) (transmission state S _t22). The token containing this data is called a busy token.
(Procedure B3) Each terminal determines whether or not the data in the passed token is addressed to itself, and if not, it passes to the next terminal (transmission state _St23 ).
(Procedure B4) When the terminal P _E has received the corresponding data (transmission state _{St 24} ), the terminal _PE extracts the data from the token to make it empty, and flows the free token over the network again.

  Further, from the viewpoint of the media access method, the CSMA / CD method and the token passing method will be described in detail.

  IEEE 802.3, IEEE 802.4, and IEEE 802.5 standardize the LAN, but the biggest difference between these three standards is the media access method. That is, IEEE 802.3 uses the CSMA / CD method, and IEEE 802.4 and IEEE 802.5 use the token passing method.

In the CSMA / CD system, data communication is performed according to the following procedure.
(Procedure C1) When there is data to be transmitted, it is checked whether the network can communicate. That is, it is checked whether the communication line is free.
(Procedure C2) If the communication line is free, data is transmitted.

However, when another node transmits data in a short time between the procedure C1 and the procedure C2, a collision (collision) occurs.
(Procedure C3) When this collision is detected, after waiting for a while, the procedure C1 is started again.

In the token passing method, data communication is performed according to the following procedure.
(Procedure D1) A small packet data called a token is circulated to each terminal of the network. There are two states for tokens: free and busy.
(Procedure D2) When the terminal receives a free token, when there is no data to be transmitted, the terminal passes as it is, and when there is data to be transmitted, the token is changed to a busy state, and the destination and data are transferred to the token. Append and send.
(Procedure D3) When the terminal receives a busy token, it first checks the destination. If it is addressed to itself, the data is received, and a reception completion mark is added and transmitted. If it is not addressed to you, let it pass.
(Procedure D4) When a busy token returns to the sending terminal, the terminal changes the busy state to the free state and sends it.

In remote monitoring and control systems, the above-described remote monitoring and control technology based on the token ring method (for example, see Patent Document 1) is widely known.
JP-A-8-51737 (paragraphs [0022] to [0023] etc.).

  In general, an Internet protocol (CSMA / CD system) method (hereinafter simply referred to as an Internet protocol) is used for a communication device that uses the same communication line and is connected by a loop type token ring (or FDDI (Token Passing)) method. A corresponding communication device cannot be incorporated (or updated).

For example, the loop Token Ring (or FDDI) type network TN ₁ in FIG. 13, the packet has visited all times to token ring communication device compatible TD _A ~TD _D. However, the loop token ring scheme network TN ₂ in FIG. 13, write set a communication device ED _C corresponding to Internet Protocol system within that loop (for example, embedded by the device replacement) also do, is always a cyclic packet It is not performed and communication is impossible.

  More specifically, as described in Patent Document 1 described above, when communication data circulates in the token ring system, a part of communication devices can be exchanged (or converted) to an Internet protocol system having a different data format. Therefore, since the communication apparatus of a different data communication system cannot be used at the time of facility update etc., it will be limited to the communication apparatus of the same communication system.

  The present invention has been made based on the above problems, and provides a communication device and a communication method for performing communication that is not limited to a single communication method.

In order to solve the above problem, the invention of claim 1 is a communication device for converting a communication protocol of communication data transmitted and received using a communication unit,
A communication conversion unit that performs data conversion between token data in the token ring method and Internet protocol data in the Internet protocol method ;
Position number conversion means for converting the data area by the communication conversion unit including the position number and control command data included in the token data in the remote monitoring control in the data area corresponding to the position number of the Internet protocol data ,
It is characterized by providing.

The invention of claim 2 is a communication method for converting a communication protocol of communication data transmitted and received using a communication unit,
A communication conversion step for performing data conversion between token data in the token ring method and Internet protocol data in the Internet protocol method ,
The communication conversion step includes converting the data area by including the position number and control command data included in the token data in the remote monitoring control in a data area corresponding to the position number of the Internet protocol data;
It is characterized by having .

According to the first or second aspect of the present invention, data can be transmitted and received between the token ring system and the Internet protocol , and token data and Internet protocol data can be transmitted and received in the remote monitoring control .
Can be sent and received.

  As described above, according to the first, second, third, and fourth aspects of the invention, communication that is not limited to a single communication method can be performed.

  These can contribute to the field of data communication technology.

  Hereinafter, a communication device according to an embodiment of the present invention will be described in detail with reference to the drawings.

  The embodiment of the present invention is a communication device that allows an existing token ring communication device to be used as it is, and a communication device based on Internet protocol data can be connected with the same position number.

  The communication apparatus according to the present embodiment uses an IP (Internet Protocol) remote control apparatus (hereinafter, referred to as an IP protocol) connected to a loop-type token ring (or FDDI (token passing)) system using the same communication line. Is called a distance control device).

  A configuration of a loop type token ring network system including a communication device according to the present embodiment will be described below with reference to FIG.

The loop type token ring type network TN _{1 in} FIG. 14 is the same as the loop type token ring TN ₁ in FIG. Also, replaces the communication device TD _C in the loop token ring scheme network TN ₁ to the communication device MD _C are loop token ring scheme network TN _3. Communication device MD _C can use the same communication line, those incorporating a far system device Internet Protocol system to loop Token Ring (or FDDI (token passing)) connected in the manner devices.

The configuration and operation of the communication device MD _C will be described with reference to FIG.

Communication device MD _C in Figure 1, Token Ring or FDDI mode communicating unit 11 for communicating with the Token Ring or FDDI type communication line CP _1, communication converter to convert data between token ring or FDDI system and Internet Protocol The apparatus includes a unit 12, an Internet protocol communication unit 13, and a device main body processing unit 14.

Incidentally, while the communication conversion unit 12 and the Token Ring or FDDI mode communicating unit 11 communicates with Internet protocol communication CP _2. Communication between the communication conversion unit 12 and the Internet protocol communication unit 13 is performed by Internet protocol communication CP ₃ . Portions that perform communication using the Internet protocol communication CP ₂ and the Internet protocol communication CP ₃ may be directly coupled by a communication line (or communication line).

A more detailed description of the portions of the communication device MD _C above. The basic flow of processing of the communication device MD _C in the case of reception, the process of token ring or FDDI mode communicating unit 11, the processing of the communication conversion unit 12, the processing of the Internet protocol communication unit 13, device main body processing In the order of processing of the unit 14, in the case of transmission, the processing is performed in the reverse order.

The token ring or FDDI communication unit 11 performs the following transmission / reception processing. First, the transmission process is as follows.
(Procedure E1) A small packet data called a token is circulated to each communication device of the network (for example, loop type token ring type network TN ₃ ) via the token ring or the FDDI type communication line CP ₁ . There are two states for tokens: free and busy.
(Procedure E2) When the token ring or FDDI communication unit 11 receives a free token, when there is no data to be transmitted, the token ring or the FDDI communication unit 11 passes the token as it is. The destination and data are added to the token and sent to the token ring or FDDI communication line CP ₁ .
(Procedure E3) When the token ring or FDDI communication unit 11 receives a busy token, it first checks the destination. If addressed to itself receives the data, it adds a mark of reception completion, and sends to the token ring or FDDI system communication line CP _1. If it is not addressed to you, let it pass.
(Procedure E4) When a busy token returns to the sending token ring or FDDI communication unit 11, the token ring or FDDI communication unit 11 changes the token ring or FDDI communication line from the busy state to the free state. Send to CP ₁ .

The procedure of the reception (or reception) processing of the token ring or FDDI communication unit 11 is as follows.
(Procedure F1) When a busy token addressed to itself is received, data is transmitted to the communication conversion unit 12.

  A specific data conversion operation between the token ring or FDDI system and the Internet protocol in the communication conversion unit 12 will be described below.

As the first data conversion operation, the communication conversion unit 12 edits the token data _DTK received from the token ring or FDDI communication unit 11 to match the Internet protocol (the first editing method for conversion will be described later). ) _Sent to the Internet protocol communication unit 13.

  The first editing method described above will be described with reference to FIG.

The token data _DTK in FIG. 2 includes a from code _DFR that is a code indicating a transmitting device, a to code _DTO that is a code indicating a receiving device, and general data _DTDT that is data to be carried in token data.

Internet Protocol Data D _IP, the header data D _HD including the destination device number D _RC is a number corresponding to the source device ID D _SD and destination device the corresponding number for the source apparatus, the data to be carried in the Internet Protocol General data D _IDT .

First, copy the Fromm code D _FR and toe code D _TO token data D _TK Internet protocol data D _IP source device number D _SD and the destination device number D _RC of.

Then, the general data D _TDT of the token data D _TK is converted by the first conversion method according to the data content included in the general data D _TDT and set to the general data D _IDT of the Internet protocol data D _IP .

  The first conversion method described above will be described in detail later.

A second data conversion operation, a communication conversion unit 12, a second editing method for editing (conversion to match the Internet Protocol data D _IP received from the internet protocol communication portion 13 to the token ring or FDDI method, described later Token data D _TK thus sent is sent to the token or FDDI communication unit 11.

  The second editing method described above will be described with reference to FIG. In FIG. 3, the description of the same reference numerals as those in FIG. 2 is omitted.

First, copy the transmission of Internet protocol data D _IP source device number D _SD and the destination device number D _RC in Fromm code D _FR and toe code D _TO token data D _TK.

Then, the general data D _IDT Internet Protocol data D _IP, converted by the second conversion method in accordance with the data contents included in the general data D _TDT, set to general data D _TDT token data D _TK.

  In addition, the above-mentioned 2nd conversion method is converted in the reverse procedure of a 1st conversion method.

The Internet protocol communication unit 13 performs the following transmission / reception processing. First, the transmission process is as follows.
(Procedure G1) When there is data to be transmitted, it is checked whether or not the network (for example, the loop type token ring network TN ₃ ) is communicable (that is, whether or not the line in the network is free). If the data is free, data is transmitted using (or via) the FDDI communication unit 11 and the communication conversion unit 12.
(Step G2), however, other nodes little time between processing of the processing and the communication conversion unit 12 of the token ring or FDDI mode communicating unit 11 (e.g., another communication device TD _A, TD _B, either TD _D ) Transmits data, a collision occurs. And when this collision is detected, it waits for a while and starts again from the processing of the token ring or the FDDI system communication unit 11.

The reception process of the Internet protocol communication unit 13 is as follows.
(Procedure H2) When the data received from the communication conversion unit 12 is addressed to the own device, the data is sent to the apparatus main body processing unit 14.

  Here, the first conversion method between the token data of the communication conversion unit 12 and the Internet protocol data will be described with reference to FIG. The description of the same reference numerals in FIG. 4 as those in FIGS. 2 and 3 is omitted.

  First, the data structure in the first conversion method will be described with reference to FIG.

The general data D _TDT of the token data D _TK in FIG. 4 includes one or more control data (for example, control data D _TD1 ). The control data includes POS data indicating position numbers (for example, data POS _T (1) and data POS _T (2) in FIG. 4), I data indicating control commands (for example, data I _T ( 1) and data I _T (2)).

The POS data of the token data _DTK is a position number. For example, the data is stored in 8 bits (bits). In one position number, a plurality of control data of one device can be transmitted and received. For example, it is possible to transmit / receive a control command to a disconnector of a certain switchgear and a control command to a circuit breaker with one position number.

The I data of the token data _DTK is control command data and contains data corresponding to “ON” or “OFF” of the control command.

The general data D _IDT of the Internet protocol data D _{IP in} FIG. 4 includes one or more control data (for example, control data D _ID1 ). For example, the data includes 32 bits (bits). Control data Internet Protocol data D _IP, there are several types, control control data, response control data, there is a display contact control data.

Control control data Internet Protocol data D _IP has POS data, the code data. For example, the control data D _ID11 in FIG. 4 is control data for control, and includes data POS _I (1′-1) and code data COD _I.

Response control data of the Internet Protocol data D _IP has a POS data, code data, control result. For example, control data D _ID14 in FIG. 4 is response control data, and includes data POS _I (1 ′), code data COD _I , and control result RES _I.

Internet protocol data D _IP display contact control data includes POS data, the Johen bit. For example, the control data D _ID15 in FIG. 4 is display contact control data, and has data POS _I (1 ″) and a state change bit STC _I.

  The data included in each type of control data in the Internet protocol data will be described in detail later.

POS data Internet Protocol data D _IP, the data enters in 12bit, will contain POS data token data D _TK is position number.

Code data COD _I Internet Protocol data D _IP is the same as the I data token data D _TK. An example of the code data will be described with reference to FIG. The code data I _OFF in FIG. 5 indicates the control command “OFF”, and its value is a binary number “0001”. The code data _ION indicates “ON” of the control command, and its value is a binary number “0010”. The code data I _EX indicates “third place, individual solution” of the control command, and its value is a binary number “0100”.

The control result RES _I of the Internet protocol data D _IP is a response (control result) to the control command data.

The distance control device (that is, the communication device MD _C ) checks the response as an answer to the control command data because there are times when the response (control result) to the control command data is different (that is, it does not move as controlled). .

However, in the case of control without response, if control and response are transmitted and received with one position number, a portion corresponding to the response becomes an empty data area. Therefore, the control instruction data and the response of the communication conversion unit 12, the Internet Protocol data D _IP allocated to different position numbers, are packed free data area. Communication conversion unit 12 performs data conversion based on the correspondence table table determined in advance, and the control command data and response in the token data D _TK to correspond to a single position number.

  Next, the first conversion method will be specifically described. The first conversion method has the following conversion method.

Position number conversion method, Internet Protocol data D _IP of the POS data (or the data region) performs conversion to include the control command data (POS data token data D _TK) position number. For example, for data POS _I in FIG. 6, the pre-4bit put control command data I _T as extension, add position number POS _T to the rear 8bit. Since only one control command data for one device can be transmitted / received to one position number, the extension unit switches the control command data. That is, control command data for distributing a plurality of control commands is identified by this extension unit.

Contrary to the above, the POS data of the Internet protocol data D _IP may have the front 8 bits as the position number and the rear 4 bits as the extension.

For example, the control command data of the disconnector corresponding to the data POS _I (1′-1) included in the control data D _ID11 in FIG. 4 and the data POS _I (1′-2) included in the control data D _ID12 One control command data is entered with one position number like the control command data of the circuit breaker to be performed. Similarly, the control data D _ID13 can contain one control command data with one position number.

In the control result conversion method, the control result is collated with a specific control result conversion condition, and the control result is converted according to the collation result. For example, the control result conversion condition B _ST1 in FIG. 7 converts the control result to “refractory motion” when an abnormality is detected in bit 3 of the control result. The control result conversion condition B _ST2 converts the control result to “none” when an abnormality is detected in bit2, bit1, and bit0.

Johen bit conversion method, Johen bit Internet protocol data D _IP, to convert to include specific data and auxiliary code token data D _TK. For example, for state change bit STC _I in FIG. 8, to include an extended portion X _T auxiliary code D _T.

  As described above, since the first conversion method (and the second conversion method) can pack the empty data of the Internet protocol data, the memory capacity in the Internet protocol data can be reduced by data conversion in addition to the correspondence in the update facility. And cost reduction is possible. In addition, since there is no empty data area and the data is displayed in the internet protocol data, the data is easily visible.

  Note that each procedure (or each process) of the method in the present embodiment may be implemented as a means (for example, a means in a computer program) to configure the communication apparatus in the present embodiment.

  As described above, according to the present embodiment, the apparatus of FIG. 1 and FIG. 14 is used to newly install an Internet protocol system apparatus to an apparatus connected by the loop type token ring system or the FDDI system using the same communication line. Can be incorporated into.

  In addition, the apparatus configuration of FIG. 1 and FIG. 14 can update the apparatus of the Internet protocol system from the apparatus connected by the loop type token ring system or the FDDI system using the same communication line.

  When the entire communication method is changed to the Internet protocol method by partial update from the device connected by the loop type token ring method or FDDI method to the Internet protocol method device using the same communication line, only the line connection change is required. Yes.

For example, in FIG. 9, a communication line connection change of the communication device MD _C, Internet Protocol enabled communication device ED _A, ED _B, ED _D connects the Internet protocol communication portion 13 and the Internet Protocol communication line CP4 in Figure 10 In other words, since the entire communication line is connected to the Internet protocol (that is, the Internet protocol network IN ₁ ), the change contents can be minimized.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

The block diagram of the communication apparatus in this embodiment. The figure which shows the 1st editing method which edits token data into Internet protocol data. The figure which shows the 2nd editing method which edits internet protocol data into token data. The figure which shows the 1st conversion method between token data and Internet protocol data. The figure which shows an example of code data. The figure which shows the position number conversion method. The figure which shows the control result conversion method. The figure which shows a state change bit conversion method. The figure which shows a mode that the whole communication system is changed into an internet protocol system by the partial update from the apparatus connected by the loop type token ring system or the FDDI system to the apparatus of an internet protocol system. The figure which shows having set it as the Internet protocol coupling | bonding by communication line connection change. The figure which shows the collision in a network. The figure which shows an example of the procedure of the information transmission in a token passing system. The figure which shows a mode that the communication apparatus corresponding to an internet protocol was integrated in the loop of a loop type | mold token ring (or FDDI) system. The figure which shows a mode that the communication apparatus in this embodiment was integrated in the loop of a loop type token ring (or FDDI) system.

Explanation of symbols

11 ... Token Ring or FDDI type communication unit 12 ... communication conversion unit 13 ... Internet protocol communication portion 14 ... apparatus body unit B _ST1, B _ST2 ... control result conversion conditions _{COD I, I OFF, I ON} , I EX ... code data CP ₁ ... Token ring or FDDI communication line CP ₂ , CP ₃ ... Internet protocol communication CP ₄ ... Internet protocol communication line D _C ... Collision domain D _FR ... From code D _HD ... Header data D _IP ... Internet protocol data D _ID1 , _{D ID11, D ID12, D ID13} , D ID14, D ID15 ... Internet control in a protocol data data D _IDT ... general data D _RC to be transported in Internet protocol data ... destination device number D _SD ... source device ID D _T ... auxiliary Code D _TD1 Token data General data D _TK ... token data D _TO ... toe code to be conveyed in the control data D _TDT ... token data in _{ED A, ED B, ED C} , ED D ... Internet Protocol enabled communication device IN ₁ ... Internet Protocol network I _T ... Control command data I _T (1), I _T (2)... I data MD _C ... Communication devices P _{A to} P _E ... Terminals POS _I , POS _I (1′-1), POS _I (1′-2), POS _I (1′-3), POS _I (1 ′), POS _I (1 ″)... POS data in Internet protocol data POS _T , POS _T (1), POS _T (2)... POS data in token data (Position number)
RES _I ... control result STC _I ... Johen bit _{S t11, S t12, S t21} ~S t24 ... transmission condition T _1, T ₂ ... terminating resistor _{TN 1, TN 2, TN 3} ... loop token ring scheme network TD _A ~TD _D ... token ring compatible communication device X _T ... extension

Claims (2)

A communication device that converts a communication protocol of communication data transmitted and received using a communication unit,
A communication conversion unit that performs data conversion between token data in the token ring method and Internet protocol data in the Internet protocol method ;
Position number conversion means for converting the data area by the communication conversion unit including the position number and control command data included in the token data in the remote monitoring control in the data area corresponding to the position number of the Internet protocol data ,
A communication apparatus comprising: A communication method for converting a communication protocol of communication data transmitted and received using a communication unit,
A communication conversion step for performing data conversion between token data in the token ring method and Internet protocol data in the Internet protocol method,
The communication conversion step includes converting the data area by including the position number and control command data included in the token data in the remote monitoring control in a data area corresponding to the position number of the Internet protocol data;
Communication method characterized by having a.

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