JPS60170353A - Data transmitting system - Google Patents
Data transmitting systemInfo
- Publication number
- JPS60170353A JPS60170353A JP2499984A JP2499984A JPS60170353A JP S60170353 A JPS60170353 A JP S60170353A JP 2499984 A JP2499984 A JP 2499984A JP 2499984 A JP2499984 A JP 2499984A JP S60170353 A JPS60170353 A JP S60170353A
- Authority
- JP
- Japan
- Prior art keywords
- communication device
- transmission
- communication
- data
- priority
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/42—Loop networks
- H04L12/427—Loop networks with decentralised control
- H04L12/433—Loop networks with decentralised control with asynchronous transmission, e.g. token ring, register insertion
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Small-Scale Networks (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は、複数の通信装置を伝送路によりループ状に接
続し、一定方向へデータの伝送を行なうデータ通信方式
に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a data communication system in which a plurality of communication devices are connected in a loop through a transmission path and data is transmitted in a fixed direction.
第１図は従来例を示すブロック図でちゃ、各々が送信端
Ｓおよび受信端Ｒを有する複数の通信装置ＣＥム〜ＣＨ
Ｄが設けられ、これらの間は伝送路Ｌ１〜Ｌ４により、
互に隣接する通信装置の送信端Ｓと受信端Ｒとが接続さ
れており、全般的に通信装置ＣＥム〜ＣＥＤが直列とし
てループ状に接続され、矢印により示す一定方向へデー
タの伝送が行なわれるものとなっている。FIG. 1 is a block diagram showing a conventional example, in which a plurality of communication devices CE to CH each have a transmitting end S and a receiving end R.
D is provided, and transmission lines L1 to L4 are provided between them.
The transmitting end S and the receiving end R of adjacent communication devices are connected, and generally the communication devices CE~CED are connected in series in a loop, and data is transmitted in a fixed direction indicated by the arrow. It has become something that can be done.
しかし、この場合は、例えば通信装置ＣＥＡとＣＥｃと
の間においてデータの送受信を行なうものとすれば、通
信装置ｃＥｎとＣＥＤとにおいて、各々受信データを自
己宛のものでないと判断のうえ送信する中継動作が行な
われるため、通信装置ＣＩＡとＣＥｃとの間におけるデ
ータ伝送に遅延を生じ、総合的な通信所要時間が大とな
る欠点を生ずる。However, in this case, if data is to be sent and received between the communication devices CEA and CEc, the communication devices cEn and CED each determine that the received data is not addressed to them, and then transmit the data. This operation causes a delay in data transmission between the communication devices CIA and CEc, resulting in a drawback that the total communication time becomes long.
本発明は、従来のかかる欠点を根本的に解決する目的を
有し、各通信装置毎に切替器を設け、自己が送信権を有
するときには切替器により送信端を送信側伝送路へ接続
し、送信権を有しないときには切替器により受信側伝送
路を直接送信側伝送路へ接続し、通信に関与しない通信
装置は伝送路中から排除するものとし、更には、送信権
の有無を判断する際、自己の送信優先度と受信した他の
送信優先度とを比較し、自己の送（ｉ優先度が他の送信
優先度に比し同等以下でないときに自己が送信権有りと
判断するものとし、優先度の付与により重要な通信の遅
滞を阻止した極めて効果的な、データ通信方式を提供す
るものである。The present invention has an object of fundamentally solving such drawbacks of the conventional technology, and includes providing a switching device for each communication device, and connecting the transmitting end to the transmitting side transmission path by the switching device when the communication device has the transmission right. When it does not have the right to transmit, the receiving side transmission line shall be directly connected to the transmitting side transmission line by a switch, and communication devices that are not involved in communication shall be excluded from the transmission line. , compares its own transmission priority with the transmission priority of other received transmissions, and determines that it has the right to transmit when its own transmission (i priority) is not equal to or lower than other transmission priorities. , provides an extremely effective data communication method that prevents delays in important communications by assigning priorities.
以下、実施例を示す第２図以降により本発明の詳細な説
明する。Hereinafter, the present invention will be explained in detail with reference to FIG. 2 and subsequent figures showing embodiments.
第２図は、通信装置毎の構成を示すブロック図であシ、
通信装置ＣＦの受信端Ｒには、光ファイバによる受信側
伝送路ＬＲが光電変換器０／Ｅを介して接続され、これ
と、電光変換器Ｅ１０を介する光ファイバの送信側伝送
路Ｌ８との間には、切替器ＳＷが挿入されており、通信
装置ＣＥの判断に基づく制御に応じ、自己に送信権が有
るときは通信装置ＣＥの送信端Ｓを選択し、送信権を有
しないときには受信側伝送路ＬＲ側を選択し、送信側伝
送路Ｌ８へ接続するものとなっている。FIG. 2 is a block diagram showing the configuration of each communication device.
An optical fiber receiving transmission line LR is connected to the receiving end R of the communication device CF via a photoelectric converter 0/E. A switch SW is inserted in between, and according to the control based on the judgment of the communication device CE, it selects the transmitting end S of the communication device CE when it has the right to transmit, and selects the transmitting end S of the communication device CE when it does not have the right to transmit. The side transmission line LR side is selected and connected to the transmission side transmission line L8.
したがって、切替器ＳＷが受信端Ｒ側を選択していれば
、通信装置ＣＥは受信のみが可能となり、伝送路中から
排除され、受信側伝送路ＬＲからの信号がそのｉま送信
側伝送路Ｌ８へ送信され、通信装置ＣＥの介在による伝
送上の遅延が全く生じないものとなる。Therefore, if the switch SW selects the receiving end R side, the communication device CE is enabled only for reception, is excluded from the transmission path, and the signal from the receiving side transmission path LR is transferred to the transmitting side transmission path. It is transmitted to L8, and there is no transmission delay due to the intervention of the communication device CE.
また、切替器ＳＷが渚信端Ｓ側を選択すれば、画伝送路
Ｌ Ｒ＋ Ｌ ｓ間が分離され、通信装置ＣＥは送信お
よび受信が自在となる。Furthermore, if the switch SW selects the shore terminal S side, the image transmission paths L R + L s are separated, and the communication device CE becomes free to transmit and receive.
第３図は、第２図の構成に基づく全体のブロック図であ
り、各変換器０／Ｅ 、Ｅ／’Ｏｔ−省略すると共に、
通信状況の推移に応じた切替器ＳＷＡ〜ＳＷ。FIG. 3 is an overall block diagram based on the configuration of FIG. 2, in which each converter 0/E, E/'Ot is omitted, and
Switching devices SWA to SW according to changes in communication status.
の選択状況を（５）〜（Ｅ）にわたって示しており、第
４図には、第２図の各段階と対応する各種信号の送受信
状況を示しておる。The selection status is shown in (5) to (E), and FIG. 4 shows the transmission/reception status of various signals corresponding to each stage of FIG. 2.
ここにおいて、まず、第３図（４）および第４図のとお
り、通信装置ＣＥＡが送信権を有し、データ信号ＤＴ＾
を送信端Ｓから通信装置ＣＥＣ宛に送信する一方、これ
を受信端Ｒから受信した通信装置ＣＥｃが応答信号ＡＳ
ｃを送信すれば、これが通信装置ＣＩＡの受信端Ｒへ与
えられ、通信装置ＣＥＡとＣＥｃとの間においてデータ
通信が行なわれる。Here, first, as shown in FIG. 3 (4) and FIG. 4, the communication device CEA has the transmission right, and the data signal DT^
is sent from the sending end S to the communication device CEC, while the communication device CEc, which received it from the receiving end R, sends a response signal AS.
When c is transmitted, it is given to the receiving end R of the communication device CIA, and data communication is performed between the communication devices CEA and CEc.
ついで、通信装置ＣＩＡがデータ信号ＤＴＡの送信およ
びデータ信号ＡＳＣの受信を終了すると、通信装置ＣＥ
Ａへ終了信号ＣＤｃを送信するだめ、通信装置ＣＥｃは
、終了信号ＣＤｃの受信に応じ確認信号ＣＵｃを送信し
、その直後、切替器ＳＷｃを受信端Ｒ側とすることによ
り、第３図（Ｂ）のとおりになり、通信装置ＣＢｓ〜Ｃ
ＥＤがすべて受信のみの受信モードとなる。Then, when the communication device CIA finishes transmitting the data signal DTA and receiving the data signal ASC, the communication device CE
Instead of transmitting the end signal CDc to A, the communication device CEc transmits a confirmation signal CUc in response to receiving the end signal CDc, and immediately after that, sets the switch SWc to the receiving end R side. ), and the communication devices CBs to C
All EDs are in reception mode, where only reception is possible.
通信装置ＣＩＡは、確認信号ＣＵｃを受信した後、通信
装置ＣＥｃが切替器ＳＷｃを（Ｂ）の状態とするまでの
所定時間を経てから、第４図のとおり送信権を引継がせ
る旨を示す引継信号ＣＰを送信するため、これが他の通
信装置ＣＥｓ ” ＣＥｏ において受信され、通信装
置ＣＥＢが送信すべきデータを有するものとすれば、自
己の切替器ＳＷＢを制御して送信端Ｓ側とし、第３図（
Ｃ）の送信モードとなって待機する。After the communication device CIA receives the confirmation signal CUc, after a predetermined period of time has elapsed until the communication device CEc sets the switch SWc to the state (B), the communication device CIA sends a takeover signal indicating that the transmission right is to be taken over as shown in FIG. In order to transmit a signal CP, if this is received by another communication device CEs'' CEo and the communication device CEB has data to be transmitted, it controls its own switch SWB to switch to the sending end S side and Figure 3 (
It enters the transmission mode of C) and waits.
ついで、通信装置ＣＩＡは、送信データを有する他の通
信装置が切替器を（Ｃ）の状態とするまでの所要時間を
経た後、更に通信装置ＣＥＡが送信データを有する場合
は、送信権の要求を示す要求信号ＣＴＡに対し、送信デ
ータの優先度を示す優先度コード（１）を付加のうえ、
これらを要求信号ＣＴＡ （ＩＩ）として第４図のとお
り送信する。Next, after the time required for another communication device that has the transmission data to set the switch to the state (C), if the communication device CEA also has the transmission data, the communication device CIA requests the transmission right. A priority code (1) indicating the priority of the transmission data is added to the request signal CTA indicating the
These are transmitted as a request signal CTA (II) as shown in FIG.
すると、これが通信装置ＣＥＨにおいて受信され、自己
の有する送信データの優先度が（１）であれば、これと
の比較により自己が優先的に送信権を占有すべきものと
判断し、通信装置ＣＥｓが優先度コード（１）を付加の
うえ要求信号ＣＴＢ（１）を第４図のとおり送信するた
め、これが通信装置ＣＥＡにおいて受信される。Then, if this is received by the communication device CEH and the priority of the transmission data it owns is (1), it is determined that it should preferentially occupy the transmission right by comparison with this, and the communication device CEs The priority code (1) is added and the request signal CTB (1) is transmitted as shown in FIG. 4, so that it is received by the communication device CEA.
通信装置ＣＥＡは、受信した要求信号ＣＴＢ（１）と自
己の優先度（ＩＩ）との比較により、送信権を通信装置
ＣＥＢへ引継ぐべきものと判断し、要求信号ＣＴＢ（１
）を第４図のとおりそのまま送信してから、切替器ＳＷ
Ａを受信端Ｒ側とし、第３図（Ｄ）の状態とする。The communication device CEA compares the received request signal CTB(1) with its own priority (II), determines that the transmission right should be handed over to the communication device CEB, and transmits the request signal CTB(1).
) as shown in Figure 4, and then switch the switch SW.
A is set to the receiving end R side, and the state shown in FIG. 3(D) is established.
通信装置ＣＥＡから転送された要求信号ＣＴＢ（１）を
通信装置ＣＥＢが受信すると、ここにおいて自己に送信
権が付与されたものとの判断がなされ、第４図のとおり
通信装置ＣＥＢから宛先アドレスおよび自己アドレスの
コードを付加した応答要求信号Ｃｏｏが送信されるため
、宛先コードによ多通信装置ＣＥＤが指定されれば、こ
れに応じて同装置ＣＥｎが切替器ＳＷｕを送信端Ｓ側と
し、第３図（６）の状態となシ、通信装置ＣＥＤが確認
信号ＣＵＤを送信するため、通信装置ＣＥａは、この確
認信号を受信してからデータ信号ＤＴａを送信し、デー
タ信号ＤＴＢの受信に応じ応答信号ＡＳＤの送信を開始
する。When the communication device CEB receives the request signal CTB(1) transferred from the communication device CEA, it is determined that the transmission right has been granted to itself, and as shown in FIG. 4, the communication device CEB sends the destination address and Since the response request signal Coo with its own address code added is transmitted, if the multi-communication device CED is specified by the destination code, the device CEn accordingly sets the switch SWu to the sending end S side and In the state shown in FIG. 3 (6), the communication device CED transmits the confirmation signal CUD, so the communication device CEa transmits the data signal DTa after receiving this confirmation signal, and responds to the reception of the data signal DTB. The transmission of the response signal ASD is started.
したがって、通信装置ＣＥＢ Ｉ ＣＥｏとの間におい
て、データ通信が行なわれ、これの終了に応じて以上の
各動作が反復されるものとなり、各通信装置ＣＥＡ〜Ｃ
ＥＤにおいて、高優先度のデータから逐次送信がなされ
るため、重要なデータの送信に遅滞を生じ々いものとな
る。Therefore, data communication is performed with the communication device CEB I CEo, and each of the above operations is repeated in response to the end of the data communication, and each communication device CEA to C
In ED, since data is transmitted sequentially starting from high priority data, delays in transmitting important data are likely to occur.
第５図は、引継信号ＣＴを受信してから以降の通信装置
ＣＥＡ −ＣＥＤによる判断および動作状況を示すフロ
ーチャートであり、プロセッサおよびメモリ等からなる
制御部を備えることにより、これらを実現することがで
きる。FIG. 5 is a flowchart showing the judgment and operation status of the communication device CEA-CED after receiving the takeover signal CT, and these can be realized by providing a control section consisting of a processor, memory, etc. can.
すなわち、引継信号”ｃｐ受信？ ” １０１がＹＥＳ
と々れば、自己に“送信データあり？ ” １０２を判
断し、これのＹＥＳに応じて切替器ＳＷを制御し“送信
モード設定”１０３を打力い、要求信号“ＣＴ受信？”
１０４がＹＥＳとなれば”自己優先度≦受信優先度？”
１０５を判断のうえ、これのＹＥＳに応じて６受信ＣＴ
転送”１０＠を行なってから切替器ＳＷを制御し、”受
信モード設定°“１０７を行なう。In other words, the takeover signal "CP reception?" 101 is YES
If so, it determines ``Is there data to be transmitted?'' 102, and in response to YES, controls the switch SW, presses ``Set Transmission Mode'' 103, and issues a request signal ``CT Reception?''
If 104 is YES, “self priority ≦ reception priority?”
After determining 105, if YES to this, 6 reception CT
After performing "transfer" 10@, the switch SW is controlled and "receiving mode setting °" 107 is performed.
一方、ステップ１０５がＮＯであれば、自己の優先度が
他の優先度に比し同等以下でなく、自己に送信権が有る
ため、”自己ＣＴ送信”１１１を行ない、要求信号”Ｃ
Ｔ受佃？°′１１２のＹＥＳに応じ、これが”自己ＣＴ
？”１１３を判断し、これのＹＥＳにしたがって”デ
ータ送信”１１４へ移行する。On the other hand, if step 105 is NO, its own priority is not equal to or lower than other priorities and it has the right to transmit, so it performs "Self CT Send" 111 and sends a request signal "C".
T uke Tsukuda? In response to YES at °'112, this is the "self-CT"
? ``113'' is determined, and in accordance with YES, the process moves to ``data transmission'' 114.
なお、優先度は、各送信データ毎に重要度を示すコード
を付加するものとすればよく、これの等級は（１） 、
（Ｉｆ）のみならず、条件に応じて定めればよい０
このほか、ステップ１０３まだは１１１についでタイマ
ーを起動し、これがタイムアツプするまでの一定時間中
にステップ１０４または１１２がＹＥＳとならなければ
、強制的にステップ１０７へ移行するものとしてもよく
、データ信号ＤＴの宛先アドレスにより、送信権を有す
る通信装置以外のすべてが同時に指定されたときは、指
定された各通信装置が受信モードを維持するものとして
もよい。Note that the priority may be determined by adding a code indicating the importance to each transmitted data, and the rank of this is (1),
In addition to (If), it can be determined according to the conditions. In addition, a timer is started after step 103 or 111, and if step 104 or 112 does not become YES within a certain period of time until the timer expires. , the process may be forcibly shifted to step 107, and when all communication devices other than those having transmission rights are simultaneously specified by the destination address of the data signal DT, each specified communication device maintains the reception mode. It may also be something to do.
また、第２図においては、切替器ＳＷを光スィッチとし
、各変換器０７Ｅ、Ｉ１０を通信装置ＣＥ内へ設けても
よく、各伝送路Ｌ Ｒ＋ Ｌ ８が電気信号を通ずるも
のであれば、各変換器０／Ｅ、Ｅ１０を省略し、切替器
ＳＷに一般のスイッチを用いればよい等、本発明は種々
の変形が自在である。In addition, in FIG. 2, the switch SW may be an optical switch, and each converter 07E, I10 may be provided in the communication device CE, and if each transmission line L R+ L 8 is one that passes an electric signal, The present invention can be modified in various ways, such as omitting the converters 0/E and E10 and using a general switch as the switch SW.
以上の説明により明らかなとおり本発明によれば、デー
タ伝送上総合的な通信所要時間が短縮される一方、重要
なデータの送信に遅滞を生ぜず、ビル管理設備の各端末
間データ通信等、多数の通信装置がループ状に接続され
る各種のデータ通信において顕著な効果が得られる。As is clear from the above explanation, according to the present invention, the overall communication time required for data transmission is shortened, and there is no delay in transmitting important data, and data communication between terminals of building management equipment, etc. Remarkable effects can be obtained in various data communications in which a large number of communication devices are connected in a loop.
第１図は従来例を示すブロック図、第２図以降は本発明
の実施例を示し、第２図は通信装置毎の構成を示すブロ
ック図、第３図は全体のブロック図、第４図は各種信号
の送受信状況を示す図、第５図は判断および動作状況を
示すフローチャートである。
ＣＥ、ＣＥ＾〜ＣＥＤ ・・・−通信装置、Ｓ−・・・
送信端、Ｒ１１ｅ ＊−受信端、ＳＷ、ｓｗＡ〜ｓｗＤ
・・・・切替器、ＬＲ・・自・受信側伝送路、Ｌ８・・
・・送信側伝送路、Ｌ１〜Ｌ４・・ｅ・伝送路。
特許出願人 山武ハネウェル株式会社
代理人 山川数構（ほか２名）
第１図
第２図
第３図
（Ａ）
第３図
（Ｂ）
（Ｃ）
第３図
（Ｄ）
（Ｅ）Fig. 1 is a block diagram showing a conventional example, Fig. 2 and subsequent figures show embodiments of the present invention, Fig. 2 is a block diagram showing the configuration of each communication device, Fig. 3 is an overall block diagram, and Fig. 4 5 is a diagram showing the transmission/reception status of various signals, and FIG. 5 is a flowchart showing the judgment and operation status. CE, CE^~CED...-Communication equipment, S-...
Transmission end, R11e *-Reception end, SW, swA to swD
...Switcher, LR...Local/receiving side transmission line, L8...
...Transmission side transmission line, L1 to L4...e transmission line. Patent applicant: Yamatake Honeywell Co., Ltd. Agent: Kazuha Yamakawa (and 2 others) Figure 1 Figure 2 Figure 3 (A) Figure 3 (B) (C) Figure 3 (D) (E)
Claims (2)
状に接続し、一定方向へデータの伝送を行なうデータ伝
送方式において、前記通信装置の受信端へ接続された受
信側伝送路と前記通信装置の送信端とを選択し送信側伝
送路へ接続する切替器を前記各通信装置毎に設け、自己
の通信装置が送＠権を有するときに前記切替器により前
記送信端を選択し、前記自己の通信装置が前記送信権を
宿しないときには前記切替器により前記受信側伝送路を
選択することを特徴としたデータ通信方式。(1) In a data transmission method in which a plurality of communication devices are connected in series in a loop through a transmission path and data is transmitted in a fixed direction, a receiving side transmission path connected to a receiving end of the communication device and the communication device A switching device is provided for each of the communication devices to select the sending end and connect it to the sending side transmission line, and when the own communication device has the transmission right, the switching device selects the sending end and connects the sending end to the sending side transmission path. A data communication system characterized in that when the communication device does not have the transmission right, the receiving side transmission path is selected by the switching device.
状に接続し、一定方向へデータの伝送を行なうデータ伝
送方式において、前記通信装置の受信端へ接続された受
信側伝送路と前ｄ己通信装置の送信端とを選択し送信側
伝送路へ接続する切替器を設け、自己の送信優先度と受
信した他の送信優先度とを比較し、前記自己の送信優先
度が前記他の送信優先度に比し同等以下でないときに自
己の、通信装置が送信権布シと判断して前記切替器によ
り前記送信端を選択し、前記比較により前記自己の通信
装置が送信権を有しないと判断したときには前記切替器
により前記受信側伝送路を選択することを特徴としたデ
ータ通信方式。(2) In a data transmission method in which a plurality of communication devices are connected in series in a loop through transmission paths and data is transmitted in a fixed direction, the receiving side transmission path connected to the receiving end of the communication device and the front d A switch is provided to select the transmitting end of the communication device and connect it to the transmitting side transmission path, and compares its own transmission priority with the other received transmission priority, and determines whether the self transmission priority is the same as the other transmission priority. If the priority is not equal to or lower than the priority, the own communication device determines that the transmission right has been granted and selects the transmission end by the switching device, and the comparison determines that the own communication device does not have the transmission right. A data communication system characterized in that when a determination is made, the receiving side transmission path is selected by the switching device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2499984A JPS60170353A (en) | 1984-02-15 | 1984-02-15 | Data transmitting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2499984A JPS60170353A (en) | 1984-02-15 | 1984-02-15 | Data transmitting system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60170353A true JPS60170353A (en) | 1985-09-03 |
Family
ID=12153667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2499984A Pending JPS60170353A (en) | 1984-02-15 | 1984-02-15 | Data transmitting system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60170353A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63236438A (en) * | 1987-03-25 | 1988-10-03 | Toshiba Corp | Modem |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5523629A (en) * | 1978-08-07 | 1980-02-20 | Mitsubishi Electric Corp | Loop transmission system |
| JPS5559536A (en) * | 1978-10-30 | 1980-05-06 | Hitachi Ltd | Bus priority control system in loop bus network system |
| JPS5632854A (en) * | 1979-08-24 | 1981-04-02 | Hitachi Zosen Corp | Control method for occupying right of data highway |
| JPS57201353A (en) * | 1981-06-03 | 1982-12-09 | Toshiba Corp | Data transmission system |
| JPS58212244A (en) * | 1982-06-03 | 1983-12-09 | Fuji Electric Co Ltd | Controlling system of loop transmission |
-
1984
- 1984-02-15 JP JP2499984A patent/JPS60170353A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5523629A (en) * | 1978-08-07 | 1980-02-20 | Mitsubishi Electric Corp | Loop transmission system |
| JPS5559536A (en) * | 1978-10-30 | 1980-05-06 | Hitachi Ltd | Bus priority control system in loop bus network system |
| JPS5632854A (en) * | 1979-08-24 | 1981-04-02 | Hitachi Zosen Corp | Control method for occupying right of data highway |
| JPS57201353A (en) * | 1981-06-03 | 1982-12-09 | Toshiba Corp | Data transmission system |
| JPS58212244A (en) * | 1982-06-03 | 1983-12-09 | Fuji Electric Co Ltd | Controlling system of loop transmission |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63236438A (en) * | 1987-03-25 | 1988-10-03 | Toshiba Corp | Modem |
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