DK166525B1 - PROCEDURE FOR CHECKING AN INTERFACE COMPONENT - Google Patents

PROCEDURE FOR CHECKING AN INTERFACE COMPONENT Download PDF

Info

Publication number
DK166525B1
DK166525B1 DK661287A DK661287A DK166525B1 DK 166525 B1 DK166525 B1 DK 166525B1 DK 661287 A DK661287 A DK 661287A DK 661287 A DK661287 A DK 661287A DK 166525 B1 DK166525 B1 DK 166525B1
Authority
DK
Denmark
Prior art keywords
monitoring
simulation
couplings
coupling
supply
Prior art date
Application number
DK661287A
Other languages
Danish (da)
Other versions
DK661287D0 (en
DK661287A (en
Inventor
Bruno Steis
Alfred Jugel
Horst Martin
Original Assignee
Siemens Ag
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Siemens Ag filed Critical Siemens Ag
Publication of DK661287D0 publication Critical patent/DK661287D0/en
Publication of DK661287A publication Critical patent/DK661287A/en
Application granted granted Critical
Publication of DK166525B1 publication Critical patent/DK166525B1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
    • H04Q11/0421—Circuit arrangements therefor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/22—Arrangements for supervision, monitoring or testing
    • H04M3/24—Arrangements for supervision, monitoring or testing with provision for checking the normal operation
    • H04M3/244—Arrangements for supervision, monitoring or testing with provision for checking the normal operation for multiplex systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
  • Maintenance And Management Of Digital Transmission (AREA)
  • Time-Division Multiplex Systems (AREA)
  • Testing Or Measuring Of Semiconductors Or The Like (AREA)
  • Electrophonic Musical Instruments (AREA)
  • Electrically Operated Instructional Devices (AREA)
  • Eye Examination Apparatus (AREA)
  • Memory System Of A Hierarchy Structure (AREA)
  • Testing Of Individual Semiconductor Devices (AREA)
  • Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)

Abstract

In an interface unit (FAU) for connecting a PCM transmission path (PCM-Ü) to an exchange of a TDM telecommunications system, the supervisory circuits (Ü1 to Ün) of the system, which monitor information transmission criteria, should be monitored in such a way that their actual function is interrupted for a short time only. To achieve this, they are supplied successively with simulated parameters corresponding to an error event, even if they transmit one group- individual alarm signal only. If an error signal is produced, the supply of simulated parameters is immediately interrupted. If no error signal of this type occurs, the simulated parameters are fed in at least once more. <IMAGE>

Description

DK 166525 B1DK 166525 B1

Opfindelsen angår en fremgangsmåde til kontrol af en interfacekomponent til forbindelse af en PCM-overføringsstrækning i et digitalt tidsmultipleks-tele-kommunikationssystem med en formidlingsplads i dette 5 telekommunikationssystem, hvilken komponent bl.a. er udstyret med en række overvågningskoblinger, som bedømmer forskellige kriterier for informationsoverføringen over PCM-strækningen, og evt. disse tilknyttede fejltællere.The invention relates to a method for controlling an interface component for connecting a PCM transmission line in a digital time multiplex telephony communication system with an intermediate location in this telecommunication system. is equipped with a series of monitoring links that assess different criteria for the transmission of information over the PCM section, and possibly these associated error counters.

10 En sådan interfacekomponent er beskrevet i en artikel i Telcom Report, bind 8, nr. 5, side 321-326 med titlen "Wartung von PCM-Anschlussen in System EWSD, og er i praksis udformet som en høj integreret komponent og konciperet således, at den er egnet til 15 universel anvendelse. Den opfylder i den forbindelse relativt komplekse funktioner. Hertil hører foruden tilpasningen af strækningstakten til formidlingstakten og tilpasningen af strækningsimpulsrammen til formidlingspladsens impulsramme bl.a. i relation til modtagne 20 digitalsignaler funktioner som modforvrængning, niveautilpasning, strækningstaktudvindelse, afkodning af HDB3-koden, udblænding af impulsramme-meldingsordet og i relation til afgående digitalsignaler indføjning af impulsramme-kendingsordet og af impulsramme-meldings-25 ordet, HDB3-kodning samt udsendelse af det afgående digitalsignal.10 Such an interface component is described in an article in Telcom Report, Vol. 8, No. 5, pages 321-326, entitled "Wartung von PCM-Anschlussen in System EWSD, and is in practice designed as a highly integrated component and thus designed, it is suitable for 15 universal applications, it performs relatively complex functions in this connection. , decoding the HDB3 code, flashing the pulse frame message word and in relation to outgoing digital signals insertion of the pulse frame recognition word and of the pulse frame message word, HDB3 encoding as well as transmitting the outgoing digital signal.

Ved en foreslået diagnose- og kontrolprocedure, jf. DK patentansøgning nr. 6611/87, foretages der på den ene side rutinekontroller under den bestående for-30 midlingsdrift af formidlingspladsen og på den anden side diagnosekontroller, som navnlig tjener til fejllokalisering og overvågning i tilkoblingstilfældet, og under hvis varighed der ikke er nogen formidlingsdrift.In a proposed diagnostic and control procedure, cf. DK Patent Application No. 6611/87, routine checks are performed on the one hand during the existing dissemination operation of the mediation site and on the other, diagnostic checks, which mainly serve to locate and monitor the connection case. , and for the duration of which there is no dissemination operation.

Af rutinekontrollerne berøres i det foreslåede 35 tilfælde i første linie overvågningskoblingerne, der er bestanddele af en sådan interfacekomponent.Of the routine controls, in the proposed case, in the first line, the monitoring couplings which are constituents of such an interface component are affected.

DK 166525 B1 2 I det mindste en del af disse overvågningskoblinger er sammenfattet til overvågning af fejl i en gruppe af fejl, som tilhører den samme fejlkategori og følgelig også nødvendiggør den samme reaktion. Sammen-5 fatningen sker på den måde, at disse overvågningskoblinger sammen frembringer et alarmsignal, som da ganske vist ikke giver nogen anvisning på, hvilken fejl der netop foreligger inden for den pågældende kategori.At least part of these monitoring couplings are summarized for monitoring faults in a group of faults belonging to the same fault category and consequently also necessitating the same response. The summary is done in such a way that these monitoring couplings together produce an alarm signal, which does not, however, give any indication of the error that exists precisely within the category concerned.

Ved rutinekontrollerne i den foreslåede kontrol-10 procedure er den bestemmelsesmæssige drift af inter-facekomponenten ganske vist ikke afbrudt, men under forløbet af sådanne rutinekontroller er overvågnings-koblingerne virkningsløse med hensyn til- deres overvågningsopgave .The routine checks in the proposed control procedure do not interrupt the determined operation of the interface component, but during the course of such routine checks, the monitoring couplings are ineffective with regard to their monitoring task.

15 Opfindelsen har til opgave at angive en frem gangsmåde, ved hvilken kontrolforløbet ved kontrollen af overvågningskoblingerne styres således, at den bestemmelsesmæssige drift af interfacekoblingen ikke afbrydes, og at overvågningskoblingerne udtages af deres 20 overvågningsopgave så kortvarigt som muligt, hvorhos kontrolresultatet så pålideligt som muligt skal angive, at der faktisk foreligger en fejl, og også differentieret skal kunne konstatere sådanne overvågningskoblinger, der på den nævnte måde er sammenfattet til kontrol 25 af fejl i den samme kategori.The invention has for its object to provide a method in which the control process in controlling the monitoring couplings is controlled so that the determined operation of the interface coupling is not interrupted and that the monitoring couplings are taken out of their monitoring task as briefly as possible, where the control result must be as reliable as possible. indicate that there is in fact an error and must also be able to differentially detect such monitoring couplings which in the said manner are summarized for checking 25 errors in the same category.

Ifølge opfindelsen løses denne opgave ved, at overvågningskoblingerne under den uændret vedvarende bestemmelsesmæssige drift af interfacekomponenten, også hvis de normalt som følge af de af dem overvågede kri-30 teriers slægtsskab med kriterier, som overvåges af én eller flere andre overvågningskoblinger, sammen med disse overvågningskoblinger kun afgiver et gruppeindividuelt alarmsignal, efter hinanden underkastes en rutinekontrol på den måde, at de foruden at blive påvir-35 ket af de kriterier, som de skal overvåge, påvirkes af simulationsstørrelser, som svarer til en fejl, hvorhos DK 166525 B1 3 tilførslen af simulationsstørrelser i tilfælde af afgivelse af et alarmsignal fra overvågningskoblingerne afbrydes umiddelbart, og tilførslen af simulationsstør-relser i tilfælde af udeblivelse af et alarmsignal, som 5 betyder en fejl, gentages mindst en yderligere gang, og at der under kontrolfasen ikke foretages nogen af de foranstaltninger, der er påtænkt for det tilfælde, at der foreligger en faktisk fejl.According to the invention, this task is solved by monitoring the couplings during the unchanged continuous operation of the interface component, even if, as a result of the kinship of the monitored criteria, they are met with criteria monitored by one or more other monitoring couplings, together with these monitoring couplings. only give a group individual alarm signal, one after the other being subjected to a routine check in such a way that, in addition to being influenced by the criteria which they must monitor, they are affected by simulation sizes corresponding to an error, which is the reason why DK 166525 B1 3 is applied. simulation magnitudes in the event of an alarm signal being output from the monitoring couplings are immediately interrupted and the supply of simulation magnitudes in the event of failure of an alarm signal signifying an error is repeated at least one more time and no measures are taken during the control phase. , intended for d a case of an actual error.

Opfindelsen er i det følgende forklaret nærmere 10 på grundlag af et udførelseseksempel og med henvisning til tegningen, hvor fig. 1 viser interfacekoblinger af_den art, som fremgangsmåden ifølge opfindelsen vedrører,- indordnet i et digitalt tidsmultipleks-telekommunikationssystem, og 15 fig. 2 en række overvågningskoblinger i en in- terfaceenhed med deres tilknytning til det PCM-over-føringssystem, til hvis overvågning de tjener, og til en styring, som bevirker deres kontrol.The invention is explained in greater detail in the following on the basis of an exemplary embodiment and with reference to the drawing, in which fig. 1 shows interface couplings of the kind to which the method of the invention relates, arranged in a digital time multiplex telecommunication system, and FIG. 2 shows a series of monitoring couplings in an interface unit with their connection to the PCM transmission system to which monitoring they serve and to a control which exerts their control.

Fig. 1 viser dele af en formidlingsplads i et 20 digitalt tidsmultipleks-telekommunikationsnet. Det er et dubleret koblingsnet SN samt tilslutningsgrupper LTGl-LTGn til tilslutning af PCM-overføringsstræknin-ger PCM-ϋ, der etablerer forbindelser til yderligere sådanne formidlingspladser.FIG. 1 shows portions of a switching location in a digital time multiplex telecommunications network. It is a duplicated switching network SN as well as connection groups LTG1-LTGn for connection of PCM transmission lines PCM-ϋ, which establishes connections to further such switching locations.

25 > Tilslutningsgrupperne LTGl-LTGn omfatter for deres vedkommende hver især en interfaceenhed LIU, over hvilken der etableres en forbindelse til koblingsfeltet SN, endvidere en gruppekobler GS samt inter-faceenheder DIU til digitale overføringssystemer, 30 hvis egentlige interfacedel er interfacekomponenten FAU, som fremgangsmåden ifølge opfindelsen vedrører, og som etablerer en forbindelse til en af de allerede nævnte PCM-overføringsstrækninger PCM-U.25> The LTG1-LTGn connection groups each comprise an interface unit LIU, over which a connection is established to the switch field SN, a group switcher GS as well as interface units DIU for digital transmission systems, the actual interface part of which is the interface component FAU, as the method of the invention relates to and which establishes a connection to one of the PCM transfer lines PCM-U already mentioned.

Interfacekomponenten FAU står under styrepå-35 virkning fra en styring DIU-C.The interface component FAU is under the control of a DIU-C control.

En tilslutningsgruppe LTG kan omfatte indtil fire interfaceenheder DIU.A connection group LTG can comprise up to four interface units DIU.

DK 166525 B1 4DK 166525 B1 4

I fig. 2 vises af en interfacekomponent FAUIn FIG. 2 is shown by an interface component FAU

blot de dele, der er af interesse i sammenhæng med udøvelsen af fremgangsmåden. Dette er i første linie overvågningskoblinger ϋΐ-ϋη, som tjener til at bedøm-5 me forskellige kriterier for informationsoverføringen over PCM-strækningen. Således tjener eksempelvis én af disse overvågningskoblinger til at overvåge den ankommende bitstrøm med hensyn til, om lovmæssigheden af den såkaldte HDB3-kode er blevet krænket gentagne gange, en 10 yderligere overvågningskobling reagerer, hvis der i den ankommende bitstrøm gennem længere tidsrum vedvarende forekommer bit med binærværdien 1, og en yderligere overvågningskobling leverer et alarmsignal, hvis der på overføringsstrækningen overhovedet ikke forekommer no-15 get PCM-signal.merely those parts of interest in the practice of the process. This is in the first line of monitoring couplings ϋΐ-ϋη, which serve to assess various criteria for the transmission of information over the PCM line. Thus, for example, one of these monitoring links serves to monitor the oncoming bitstream as to whether the legality of the so-called HDB3 code has been repeatedly violated, a further monitoring link responds if in the oncoming bitstream for longer periods of bit by the binary value 1, and an additional monitoring coupling provides an alarm signal if no transfer PCM signal is present at all on the transmission line.

Som yderligere eksempel kan nævnes en overvågningskobling, som overvåger den ankommende bitstrøm med hensyn til den tidskorrekte fremkomst af et kodeord, som definerer en overramme, og en overvågningskobling, 20 som kontrollerer den korrekte fremkomst af rammekendingsord. Til overvågningskoblingerne er der som antydet ved Un knyttet en fejltæller Z, hvis først en flerdobbelt fremkomst af en fejl bedømmes som utilladelig driftstilstand.As a further example may be mentioned a monitoring coupling which monitors the arriving bitstream with respect to the time-correct emergence of a password defining an overwrite and a monitoring coupling 20 controlling the correct emergence of frame recognition words. As indicated by Un, an error counter Z is associated with the monitoring couplings if a multiple occurrence of a fault is first considered as an inadmissible operating state.

25 De nævnte overvågningskoblinger påvirkes dels af de kriterier, der skal overvåges, dels af simulationsstørrelser, som leveres foranlediget af en simulationsstyring SIMSt, der her er vist som bestanddel af inter facestyr ingen DIU-C. Påvirkningen dels af de kri-30 terier, der skal overvåges, dels af simulationsstørrelser svarende til fejltilfældet er i figuren anskuelig-gjort ved anvendelse af ELLER-led OD, hvis ene indgang står i forbindelse med en kore i PCM-overførings-strækningen PCM-U, og hvis anden indgang er forbun-35 det med udgangen på en simulationskobling SS.25 The monitoring couplings mentioned are influenced partly by the criteria to be monitored and partly by simulation sizes provided by a simulation control SIMSt, which is shown here as a component of Interface Control no DIU-C. The influence partly of the criteria to be monitored and partly of simulation sizes corresponding to the error case is illustrated in the figure using OR-link OD, whose one input is connected to a choir in the PCM transmission line PCM. U and whose second input is connected to the output of a simulation coupling SS.

Simulationskoblingerne SS leverer hver især på grundlag af en af simulationsstyringen SIMSt afgivet simulationsordre SIMl-SIMn til et fejltilfælde sva-The simulation couplings SS each deliver on the basis of a simulation order issued by SIMSt simulation sim SIM-SIMn for an error case

Claims (2)

5 UK 166525 Bl rende simulationsstørrelser for de kriterier, der skal overvåges af den tilknyttede overvågningskobling 01-Øn. Udgangene på overvågningskoblingerne 01-On, 5 over hvilke der afgives alarmsignaler i tilfælde af en reaktion af overvågningskoblingen, er hver især forbundet med tilbagestillingsindgangen på den tilknyttede simulationskobling SS. Herved afbrydes tilførslen af simulationsstørrelser umiddelbart efter at overvåg-10 ningskoblingen har reageret, hvormed dens korrekte funktion står fast, således at der igen kan finde en normal overvågning af informationsoverføringen sted, hvilket jo ikke er muligt under kontrollen af overvågningskoblingerne, fordi afgivelsen af alarmsignaler un-15 der simulationen ikke fører til den sædvanlige reaktion, eksempelvis frakoblingsforanstaltninger. Såfremt en overvågningskobling ikke reagerer på tilførslen af simulationsstørrelser, bedømmes dette som fejl ved overvågningskoblingen. For at man imidlertid kan være 20 sikker på, at en overvågningskobling virkelig ikke arbejder korrekt, bliver tilførslen af simulationsstørrelser i et sådant tilfælde gentaget n-gange, dog mindst 2 gange efter hinanden. Først når den gentagne tilførsel har givet en bekræftelse af den ikke-korrekte 25 drift af overvågningskoblingen, foranlediges der en tilsvarende melding og en egnet koblingsforanstaltning.5 UK 166525 Current simulation sizes for the criteria to be monitored by the associated monitoring coupling 01-Island. The outputs of the monitoring couplings 01-On, 5 over which alarm signals are issued in the event of a reaction of the monitoring coupling, are each connected to the reset input of the associated simulation coupling SS. Hereby, the supply of simulation magnitudes is interrupted immediately after the monitoring coupler has reacted, with which its correct function is established, so that a normal monitoring of the information transmission can take place, which is not possible during the control of the monitoring couplings, because the alarm signals are emitted. -15 where the simulation does not lead to the usual reaction, for example disconnection measures. If a monitoring coupling does not respond to the supply of simulation sizes, this is judged to be a failure of the monitoring coupling. However, in order to be sure that a monitoring coupling is not working properly, in such a case the supply of simulation sizes is repeated n times, but at least twice in succession. Only when the repeated supply has confirmed the incorrect operation of the monitoring coupling does a corresponding message and a suitable coupling measure occur. 30 Fremgangsmåde til kontrol af en interfacekompo- nent (FAU) til forbindelse af en PCM-overføringsstrækning (PCM-Ø) i et digitalt tidsmultipleks-telekommuni-kationssystem med en formidlingsplads i dette telekommunikationssystem, hvilken komponent bl.a. er udstyret 35 med en række overvågningskoblinger (01, 02,...,On), som bedømmer forskellige kriterier for informations- DK 166525 B1 6 overføringen over PCM-strækningen, og evt. tilknyttede fejltællere (Z), kendetegnet ved, at overvågningskoblingerne under den uændret vedvarende best emmel s esmæssige drift af interfacekomponenten, også 5 hvis de normalt som følge af de af dem overvågede kriteriers slægtsskab med kriterier, som overvåges af én eller flere andre overvågningskoblinger, sammen med disse overvågningskoblinger kun afgiver et gruppeindividuelt alarmsignal, efter hinanden underkastes en ru-10 tinekontrol på den måde, at de foruden at blive påvirket af de kriterier, som de skal overvåge, påvirkes af simulationsstørrelser, som svarer til en fejl, hvorhos tilførslen af simulationsstørrelser i tilfælde af afgivelse af et alarmsignal fra overvågningskoblingerne af-15 brydes umiddelbart, og tilførslen af simulationsstørrelser i tilfælde af udeblivelse af et alarmsignal, som betyder en fejl, gentages mindst en yderligere gang, og at der under kontrolfasen ikke foretages nogen af de foranstaltninger, der er påtænkt for det tilfælde, at 20 der foreligger en faktisk fejl.A method of controlling an interface component (FAU) for connecting a PCM transmission line (PCM-)) in a digital time multiplex telecommunication system with a switching location in this telecommunication system. is equipped 35 with a series of monitoring couplings (01, 02, ..., On) which assess various criteria for the information transmission over the PCM line, and possibly. associated fault counters (Z), characterized in that the monitoring couplings during the unchanged continuous operation of the interface component, also 5 if, as a result of the relatedness of the monitored criteria, they are normally accompanied by criteria monitored by one or more other monitoring couplings with these monitoring couplings only emits a group individual alarm signal, one after the other being subjected to a routine check in such a way that, in addition to being influenced by the criteria which they must monitor, they are affected by simulation sizes corresponding to an error where the supply of simulation sizes in the case of the issuing of an alarm signal from the monitoring couplings, the interruption is immediately discontinued and the supply of simulation magnitudes in the event of the failure of an alarm signal signifying a fault is repeated at least one more time and no measures are taken during the control phase. that is intended for that case e that 20 is an actual error.
DK661287A 1986-12-17 1987-12-16 PROCEDURE FOR CHECKING AN INTERFACE COMPONENT DK166525B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3643112 1986-12-17
DE3643112 1986-12-17

Publications (3)

Publication Number Publication Date
DK661287D0 DK661287D0 (en) 1987-12-16
DK661287A DK661287A (en) 1988-06-18
DK166525B1 true DK166525B1 (en) 1993-06-01

Family

ID=6316408

Family Applications (1)

Application Number Title Priority Date Filing Date
DK661287A DK166525B1 (en) 1986-12-17 1987-12-16 PROCEDURE FOR CHECKING AN INTERFACE COMPONENT

Country Status (6)

Country Link
EP (1) EP0272513B1 (en)
AT (1) ATE66557T1 (en)
BR (1) BR8706850A (en)
DE (1) DE3772354D1 (en)
DK (1) DK166525B1 (en)
FI (1) FI87617C (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8923158D0 (en) * 1989-10-13 1989-11-29 Plessey Telecomm Fault detection and bandwidth monitoring means for an atd switch
ES2066027T3 (en) * 1990-03-23 1995-03-01 Siemens Ag CIRCUIT PROVISION FOR ROUTINE VERIFICATION OF AN INTERFACE BETWEEN CONNECTION GROUPS AND THE COUPLING NETWORK OF A TELECOMMUNICATION-PMC SWITCHING SYSTEM.

Also Published As

Publication number Publication date
BR8706850A (en) 1988-07-26
ATE66557T1 (en) 1991-09-15
FI875542A (en) 1988-06-18
FI875542A0 (en) 1987-12-16
DE3772354D1 (en) 1991-09-26
FI87617C (en) 1993-01-25
DK661287D0 (en) 1987-12-16
EP0272513A3 (en) 1988-08-03
EP0272513A2 (en) 1988-06-29
FI87617B (en) 1992-10-15
DK661287A (en) 1988-06-18
EP0272513B1 (en) 1991-08-21

Similar Documents

Publication Publication Date Title
EP0570882B1 (en) A distributed control methodology and mechanism for implementing automatic protection switching
US5233600A (en) Method and apparatus for identifying a failed span in a network of span interconnected nodes
US6466539B1 (en) Bus system
US5069521A (en) Optical transmission apparatus
KR940006367A (en) Method and system for protecting group facilities in digital telecommunication systems
US6385665B1 (en) System and method for managing faults in a data transmission system
US5473752A (en) Fault isolation circuit
DK166525B1 (en) PROCEDURE FOR CHECKING AN INTERFACE COMPONENT
JP3854372B2 (en) Optical cross-connect device
CA1299656C (en) Protection against loss or corruption of data upon switchover of a replicated system
KR100333954B1 (en) The Mehod and Apparatus of Dual Operation and Fault Detection in Optical Network Using Single Core
JP4302290B2 (en) Data transmission control system
JP2637299B2 (en) External monitoring device for communication systems
DK167792B1 (en) PROCEDURE FOR DIAGNOSTICATION AND CHECKING OF AN INTERFACE COMPONENT
JPH10313278A (en) Star type optical subscriber transmission system
JP3781523B2 (en) Optical subscriber line transmission apparatus and standby optical transmission line monitoring method
JPS6398242A (en) Series data exchanger
KR100551164B1 (en) Method for controlling link state of V5.2 protocol
JPS61274449A (en) Supervisory system for ring-shaped transmission line
JPH0454747A (en) Data transfer system
JPS63272149A (en) Alarm transferring system for remote telephone exchange
JPS6184950A (en) Exchanging system
JPH0389739A (en) Reception part duplex circuit
JPS6285544A (en) Abnormality supervisory unit
JPH0451625A (en) Fault segmenting system

Legal Events

Date Code Title Description
B1 Patent granted (law 1993)
PBP Patent lapsed