DK167792B1

DK167792B1 - PROCEDURE FOR DIAGNOSTICATION AND CHECKING OF AN INTERFACE COMPONENT

Info

Publication number: DK167792B1
Application number: DK661187A
Authority: DK
Inventors: Bruno Steis; Alfred Jugel; Horst Martin
Original assignee: Siemens Ag
Priority date: 1986-12-17
Filing date: 1987-12-16
Publication date: 1993-12-13
Also published as: FI875541A; EP0274653A2; DE3772024D1; DK661187A; EP0274653A3; AR243048A1; DK661187D0; FI88984B; BR8706853A; FI875541A0; ATE66109T1; EP0274653B1; FI88984C

Description

DK 167792 B1DK 167792 B1

Opfindelsen angår en fremgangsmåde til diagnosticering og kontrol af en interfacekomponent til forbindelse af en PCM-overføringsstrækning i et digitalt tidsmultipleks-telekommunikationssystem med en formid-5 lingsplads i et telekommunikationssystem, som foruden andre bestanddele har et talelager til tidsmæssig tilpasning af den på overføringsstrækningen dannede impulsramme efter den impulsrarame, der ligger til grund for formidlingspladsens drift, endvidere for sit ved-10 kommende er udstyret med en række forskellige kriterier for informationsoverføringen på PCM-strækningen bedømmende overvågningskoblinger, til hvilke der i det mindste tildels er knyttet fejltællere, og som over et datamatinterface står i forbindelse med en egen sty-15 ring, hvorved koblingerne samt efterkoblede fejltællere, talelageret og datamatinterfacet under den uændret vedvarende bestemmelsesmæssige drift af interfacekomponent en underkastes rutinekontroller, hvortil koblingerne foranlediget af styringen påvirkes med si-20 mulationsstørrelser, som svarer til en fejl, og hvor der med henblik på fejllokalisering og til kontrol af interfacekomponenten før idrifttagelse ved afbrudt hhv. endnu ikke påbegyndt bestemmelsesmæssig drift af interfacekomponenten dannes kontrolsløjfer.The invention relates to a method for diagnosing and controlling an interface component for connecting a PCM transmission line in a digital time multiplex telecommunication system with a transmission space in a telecommunication system which, in addition to other components, has a voice storage for temporarily adapting the impulse line formed on the transmission line. in addition, for the impulse frame on which the intermediary site operates, for its future, is equipped with a number of different criteria for the transmission of information on the PCM section judging monitoring links, to which at least in part there are error counters, and which over a the computer interface communicates with its own control, whereby the couplings and after-coupled error counters, the voice storage and the data interface during the unchanged continuous operation of the interface component are subjected to routine checks to which the couplings are caused by the control is affected by si-20 simulation sizes which correspond to a fault and where for the purpose of fault locating and for checking the interface component before commissioning at the interrupted, respectively. Determined operation of the interface component has not yet begun, control loops are formed.

25 En sådan interfacekomponent er i praksis udfor met som højintegreret komponent og konciperet således, at den er egnet til universelanvendelse. Den opfylder relativt komplekse funktioner. Hertil hører foruden den nævnte tilpasning af strækningstakten efter formid-30 lingstakten og tilpasningen af strækningsimpulsrammen efter formidlingspladsens impulsramme bl.a. i relation til modtagne digitalsignaler funktionerne modforvrængning, niveautilpasning, strækningstaktudvindelse, afkodning af HDB3-koden, udblænding af impulsramme-mel-35 dingsordet og i relation til afgående digitalsignaler eksempelvis indføjning af impulsramme-kendingsordet og 2 UK ID//yZ Dl af impulsramme-meldingsordet, HDB3-kodningen samt udsendelsen af det afgående digitalsignal.In practice, such an interface component is designed as a highly integrated component and designed to be suitable for universal use. It performs relatively complex functions. This includes in addition to the said adjusting of the stretching rate after the dissipation rate and the adaptation of the stretching pulse frame according to the impulse frame of the intermediate position, among other things. in relation to received digital signals, the functions distortion, level adjustment, stretch rate recovery, decoding of the HDB3 code, dimming of the pulse frame message word and in relation to outgoing digital signals eg insertion of the pulse frame message word and 2 UK ID // yZ Dl , The HDB3 encoding and the output of the outgoing digital signal.

Fra tidsskriftet "Telcom Report", bind 8 (1985), nr. 5 side 321-326 er det i forbindelse med ru-5 tinekontroller kendt at overvåge overvågningskoblingerne i en sådan interfacekomponent på den måde, at disse koblinger under den uforandret fortsatte bestemmelsesmæssige drift af interfacekomponenten, foranlediget af interfacekomponentstyringen, ud over de kriterier, som 10 skal overvåges, får tilført simulationsstørrelser, som svarer til en fejl, hvorved der i tilfælde af en reaktion i overvågningskoblingen som f.eks. ved optræden af en faktisk fejl i den funktion, der skal overvåges, sker fejlindikering i et tilstandsregister. I forbin-15 delse med en uden for den bestemmelsesmæssige drift liggende kontroldrift, som tjener til fejllokalisering og kontrol af interfacekomponenten forud for idriftsæt-ning, er det fra nævnte publikation endvidere kendt at danne kontrolsløjfer, som omfatter forskellige bestand-20 dele af en interfacekomponent.From the journal "Telcom Report", Volume 8 (1985), no. 5 pages 321-326, in connection with routine checks, it is known to monitor the monitoring couplings in such an interface component in such a way that these couplings during the unchanged continued operational operation of the interface component, caused by the interface component control, in addition to the criteria to be monitored, simulation sizes corresponding to an error are added, whereby in the event of a reaction in the monitoring coupling, e.g. when an actual error occurs in the function to be monitored, error indication occurs in a state register. Furthermore, in connection with an out-of-control operation which serves to locate and control the interface component prior to commissioning, from said publication it is known to form control loops comprising various components of an interface component. .

Opfindelsen har nu til opgave at anvise et sådant diagnosticerings- og kontrolkoncept for en inter-facekomponent, som både omfatter on-line og off-line kontrol af interfacekomponentens talelager.It is the object of the invention to provide such a diagnostic and control concept for an interphase component, which includes both on-line and off-line control of the interface component's voice memory.

25 Til løsning af denne opgave er fremgangsmåden ifølge opfindelsen ejendommelig ved de i patentkravets kendetegnende del angivne foranstaltninger.In order to solve this problem, the method according to the invention is characterized by the measures specified in the characterizing part of the patent claim.

Opfindelsen er i det følgende forklaret nærmere på grundlag af et udførelseseksempel og med henvisning 30 til tegningen, hvor fig. 1 viser interfacekomponenter af den art, som fremgangsmåden ifølge opfindelsen vedrører, indordnet i et digitalt tidsmultipleks-telekommunikations-system, og 35 fig. 2 et mere detaljeret blokdiagram over en sådan interfacekomponent.The invention is explained in more detail below on the basis of an exemplary embodiment and with reference to the drawing, in which fig. 1 shows interface components of the kind to which the method of the invention relates, arranged in a digital time multiplex telecommunication system, and FIG. 2 shows a more detailed block diagram of such an interface component.

3 DK 167792 B13 DK 167792 B1

Fig. 1 viser dele af en formidlingsplads i et digitalt tidsmultipleks-telekommunikationsnet. Dette er et dubleret koblingsnet SN0-SN1 samt tilslutningsgrupper LTGl-LTGn til tilslutning af FCM-overførings-5 strækninger PCM-ΰ, som etablerer forbindelser til yderligere sådanne formidlingspladser.FIG. 1 shows portions of a switching location in a digital time multiplex telecommunications network. This is a duplicate switching network SN0-SN1 as well as connection groups LTG1-LTGn for connecting FCM transmission lines PCM-ΰ, which establish connections to further such switching sites.

Tilslutningsgrupperne LTGl-LTGn omfatter for deres vedkommende hver især en interfaceenhed LIU, over hvilken der etableres en forbindelse til koblings-10 nettet SN, endvidere en gruppekobler GS samt in-terfaceenheder DIU for digitale overføringssystemer, hvis egentlige interfacedel er interfacekomponenten FAU, som fremgangsmåden ifølge opfindelsen vedrører, og som etablerer en forbindelse til en af de allerede 15 nævnte PCM-overføringsstrækninger PCM-ϋ; en tilslutningsgruppe LTG kan omfatte indtil fire interface-enheder DIU.The LTG1-LTGn connection groups each comprise an interface unit LIU, over which a connection is established to the switching network SN, a group switcher GS and 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 transmission lines PCM-allerede already mentioned; a connection group LTG can comprise up to four interface units DIU.

Interfacekomponenten FAU står under styrepåvirkning fra en styring DIU-C.The FAU interface component is controlled by a DIU-C control.

20 Det detaljerede blokdiagram over interfaceenhe- den FAU i fig. 2 viser i sendegrenen over hvilken informationer, der modtages fra koblingsnettet SN, videregives til en PCM-overføringsstrækning PCM-li's afgående gren, en kanaludvælgelseskobling IC, en kob-25 ling PG, som frembringer sendeimpulsrammen, i hvilken den til rette tid stiller et rammekendingsord og et meldingsord til rådighed, en sendekobling CLT, en kobling CRC4-G, ved hjælp af hvilken der med henblik på synkronisering indføjes bestemte bit i informations-30 strømmen, samt udstyr HDB3- E, ved hjælp af hvilket sendesignalet til overføringen kodes i den såkaldte HDB3-kode.20 The detailed block diagram of the FAU interface unit of FIG. 2 shows in the transmitting branch which information received from the switching network SN is transmitted to the outgoing branch of a PCM-transmission PCM-li, a channel selection switching IC, a coupling PG, which generates the transmit pulse frame in which it at the right time places a frame acknowledgment word and a message word available, a transmit switch CLT, a switch CRC4-G, by means of which, for synchronization, certain bits are inserted into the information stream, and equipment HDB3-E, by means of which the transmit signal for the transmission is encoded in it. so-called HDB3 code.

I den i fig. 2 viste interfacekomponents modtagegren ligger der på tilslutningssiden for PCM-stræk-35 ningen en dekoder HDB3-D, ved hjælp af hvilken det i den nævnte HDB3-kode kodede ledningssignal afkodes, et 4In the embodiment shown in FIG. 2, on the connection side of the PCM line, there is a decoder HDB3-D, by which the conduction signal encoded in said HDB3 code is decoded, a 4

Ulv IO//3Z D IWolf IO // 3Z D I

organ PS, der i første række sørger for impulsramme-synkroniseringen, et talelager SM, der som pufferlager etablerer faseforskelle mellem den ankommende bitstrøm og de tidsforhold, der ligger til grund for 5 formidlingspladsens drift, samt et organ OS, der svarende til organet IC i modtagegrenen tjener· til tidskanaludvælgelse .means PS, which primarily provides the pulse frame synchronization, a voice storage SM which, as a buffer layer, establishes phase differences between the arriving bit stream and the time conditions underlying the operation of the mediation space, and a means OS corresponding to the means IC in the receiving branch serves · for time channel selection.

Den i fig. 2 viste interfacekomponent omfatter endvidere en række overvågningskoblinger, nemlig kob-10 lingen ϋ-DCV, som overvåger den ankommende bitstrøm med hensyn til, om HDB3-kodens lovmæssighed er blevet krænket gentagne gange, en overvågningskobling O-AIS, som reagerer, hvis der i den ankommende bitstrøm over længere tidsrum vedvarende forekommer bit med binær-15 værdien 1, en overvågningskobling 0-NOS, som leverer et alarmsignal, hvis der på overføringsstrækningen overhovedet ikke forekommer noget PCM-signal, og en overvågningskobling 0-CRC4, som overvåger den ankommende bitstrøm med hensyn til den tidskorrekte fore-20 komst af et kodeord, som definerer en overramme. Den forannævnte synkroniseringskobling indeholder ligeledes en her ikke særskilt vist overvågningskobling, som kontrollerer den korrekte forekomst af rammekendingsord. Sluttelig findes der også en overvågningskobling U—SM, 25 der tjener til kontrol af talelageret SM.The FIG. 2 also comprises a series of monitoring couplings, namely the coupling DC-DCV, which monitors the arriving bit stream for repeatedly violating the law of the HDB3 code, a monitoring coupling O-AIS which responds if the arriving bit stream over a sustained period of time occurs bits with the binary value 1, a monitoring coupling 0-NOS, which provides an alarm signal if no PCM signal is present on the transmission line, and a monitoring coupling 0-CRC4 which monitors the arriving bit stream with respect to the time-correct occurrence of a password defining an over frame. The aforementioned synchronization coupling also contains a monitoring coupling not shown here, which controls the correct occurrence of frame recognition words. Finally, there is also a monitoring coupling U-SM, 25 which serves to control the voice memory SM.

Interfacekomponenten FAU bliver som omtalt styret af en styring DIU-C, der imidlertid ikke er vist i fig. 2. Informationsudvekslingen mellem denne styring og et ordreregister CR sker over en data-30 bus DB. Desuden findes der en adressebus AB, over hvilken styringen leverer aktiveringsadresser til en adressedekoder Ad-D.As mentioned, the interface component FAU is controlled by a control DIU-C, which, however, is not shown in FIG. 2. The exchange of information between this control and an order register CR occurs over a data bus DB. In addition, there is an address bus AB, over which the control delivers activation addresses to an address decoder Ad-D.

Fig. 2 viser endvidere et statusregister SR, i hvilket der er lagret angivelser om bestående alarm-35 meldinger.FIG. 2 also shows a status register SR, in which information about existing alarm messages is stored.

Til enkelte af overvågningskoblingerne er der knyttet fejltællere.Some of the monitoring connections have error counters attached.

5 DK 167792 B1 I det følgende gås der med henvisning til fig. 2 nærmere ind på fremgangsmåden ifølge opfindelsen.5 DK 167792 B1 In the following, reference is made to FIG. 2 more closely with the method according to the invention.

Denne fremgangsmåde er opdelt i såkaldte ONLINE-kontroller, ved hvis udførelse interfacekomponentens 5 bestemmelsesmæssige drift ikke afbrydes, og hvor der er tale om rutinekontroller, og i OFFLINE-kontroller, ved hvilke interfacekomponentens bestemmelsesmæssige drift afbrydes, og som tjener til fejllokalisering og til kontrol af interfacekomponenten FAU hhv. hele inter-10 facekomponenten DIU i tilkoblet tilstand. Til ONLINE-kontrollerne hører kontrollen af selve overvågningskoblingerne. Denne foretages på den måde, at de enkelte overvågningskoblinger ud over de kriterier, som de skal overvåge, får tilført simulationsstørrelser, som sva-15 rer til et fejltilfælde. (I fig. 2 antydet ved signalindgange (2) på overvågningskoblingerne). Derpå angivne fejlsignaler bliver eventuelt talt i den tilknyttede fejltæller hhv. fører til, at den tilsvarende bit sættes i statusregistret SR. Såfremt de af enkelte over-20 vågningskoblinger overvågede kriterier kan betragtes som hørende til den samme kategori og fejl følgelig kræver de samme reaktioner, er de af disse overvågningskoblinger afgivne alarmsignaler kombineret til et sumsignal.This approach is divided into so-called ONLINE controls, in which execution of the interface component 5 is not interrupted and in the case of routine checks, and in OFFLINE controls, in which the interface component determination operation is interrupted, which serves to locate and control errors. the interface component FAU respectively. the entire inter-phase component DIU in the connected state. The ONLINE controls include the control of the monitoring links themselves. This is done in such a way that the individual monitoring couplings, in addition to the criteria that they must monitor, are supplied with simulation sizes, which correspond to an error case. (In Fig. 2 indicated by signal inputs (2) on the monitoring connections). The error signals then specified are optionally counted in the associated error counter, respectively. causes the corresponding bit to be put in the status register SR. If the criteria monitored by single monitoring couplings can be considered as belonging to the same category and consequently require the same responses, the alarm signals issued by these monitoring couplings are combined into a sum signal.

25 I kontrolkoblingen PS bliver der ved simula tion frembragt slupbetingelser, som fører til afgivelse af et signal, der i normaldrift bevirker en slupudligning ved et kanaltællerspring, her i kontroldriften i-midlertid forbliver uden konsekvenser.25 In the control coupling PS, simulation conditions are generated which lead to the output of a signal which in normal operation causes a slip equalization at a channel counter jump, here in the control operation i temporarily remain without consequences.

30 Foranstaltninger, der i normale tilfælde even tuelt træffes ved reaktion af overvågningskoblingerne, udebliver under denne kontrol af overvågningskoblingerne.30 Measures normally taken in response to the monitoring couplings in normal cases will not be subject to this control of the monitoring couplings.

I tilslutning til denne kontrolfase bliver sta-35 tusregistret og fejltællerne afsprugt og udnyttet ved hjælp af styringen DIU-C. Overvågningskoblingerne 6In connection with this control phase, the STA-35 register and the error counters are tested and utilized by the DIU-C control. The monitoring couplings 6

Ulv ib//»z m står under denne kontrolfase ikke til rådighed til deres egentlige overvågningsopgaver, men på den anden side forbliver den i sammenhæng med informationsoverføringen bestående drift af interfacekoblingen opretholdt 5 uændret.During this control phase, wolf ib // »z m is not available for their actual monitoring tasks, but on the other hand, the operation of the interface coupling remains unchanged in the context of the information transfer.

I talelageret SM kan en ONLINE-kontrol ved fremgangsmåden ifølge opfindelsen udføres i to varianter.In the voice storage SM, an ONLINE check by the method of the invention can be performed in two variants.

Ved den første variant bliver relateret til en 10 enkelt lagercelle, som er tilknyttet en tidskanal, de informationer, der skal indskrives, forsynet med en paritetsbit og efter udlæsning ved hjælp af overvågningskoblingen 0-SM underkastet en paritetskontrol. (I fig. 2 antydet ved en kontrolvej SMC). Det spiller her 15 ingen rolle, hvilken tilstand den pågældende tidskanal befinder sig i, altså om kanalen er ledig eller opta get.In the first variant, related to a single storage cell associated with a time channel, the information to be entered is provided with a parity bit and after readout by the monitoring coupling 0-SM is subjected to a parity check. (In Fig. 2 indicated by a control path SMC). Here it does not matter what condition the time channel in question is in, that is, whether the channel is free or busy.

En anden kontrolvariant bliver i modsætning til den førstnævnte, hvis forløb styringen DIU-C er an-20 svarlig for, foranlediget af en overordnet styring, der vedrører samtlige tilslutningsgrupper LTGl-LTGn i fig. l. Ved denne kontrol bliver i hvert enkelt tilfælde en bestemt tidskanal blokeret formidlingsteknisk, og et kodeord med et normalt som frikanal-kode sendt 25 kodeords bitkombination formidles til den pågældende talelagercelle i talelageret SM og derfra igen sendt tilbage til formidlingspladsen, hvor det af den nævnte overordnede styring sammenlignes med bør-værdien for et frikanal-kodeord. (I fig. 2 antydet ved kontrolvejen 30 SC-L). De øvrige tidskanaler forbliver upåvirkede af denne procedure, således at der også her kan tales om en ONLINE-kontrol.Another control variant, in contrast to the former, whose operation the control DIU-C is responsible for, is caused by an overall control relating to all connection groups LTG1-LTGn in FIG. l. In this case, in each case, a particular time channel is blocked dissemination technically, and a code word with a normal free-channel code sent 25 code bit combination is transmitted to the respective voice storage cell in the voice memory SM and from there again sent back to the transmission place where said overall control is compared to the setpoint of a free channel password. (In Fig. 2 indicated by the control road 30 SC-L). The other time channels remain unaffected by this procedure, so that an online check can also be spoken here.

Sluttelig bliver også interfacet til interface-komponenten FAU's styring DIU-C kontrolleret i ON-35 LINE-drift, idet styreinformationer, der af denne styring er indlæst i styreregistret CR, udlæses ødelæg- DK 167792 B1 7 gelsesfrit under deres respektive adresser og sendes tilbage til styringen, hvor der sker en sammenligning med en pågældende bør-information. (I fig. 2 antydet ved kontrolvejen PJP).Finally, the interface of the interface component FAU's control DIU-C is also checked in ON-35 LINE operation, as control information entered by this control into the control register CR is read out destructively under their respective addresses and sent back for the control, where a comparison is made with a particular information on the should. (In Fig. 2 indicated by the control path PJP).

5 Foruden disse ONLINE-kontroller foretages der ifølge opfindelsen også OFFLINE-kontroller af inter-facekomponenten FAU, hvilke kontroller dels tjener til at foretage en fejllokalisering i tilfælde, i hvilke resultatet af ONLINE-kontrollen ikke tillader en én-10 tydig bestemmelse af fejlstedet, dels til at kontrollere interfacekomponenten FAU i tilkoblet drift.In addition to these ONLINE controls, according to the invention, OFFLINE checks are also made of the interface component FAU, which partly serves to make a fault location in cases in which the result of the ONLINE check does not allow a single clear determination of the fault location. partly to control the FAU interface component in connected operation.

Disse kontroller foranlediges ligeledes af den nævnte overordnede styring. De udføres i en driftstilstand, i hvilken der ikke finder nogen formidlingstek-15 nisk drift sted, ved dannelse af kontrolsløjfer, som valgfrit kontrollerer forskellige bestanddele af interfacekomponenten og derudover af komponentgruppen DIU, der er bestanddel af interfacekomponenten. I tilfælde af en kontrol, der omfatter talelageret, bliver 20 et kontrolmønster tilført modtageindgangen DXI på komponenten IC i interfacekomponentens modtagegren i samtlige kanaler, hvorhos indholdet af hver to på hinanden følgende impulsrammer er forsynet med en paritetsbit, således at der er taget hensyn til det ramme-25 vise skift af synkroniseringsord og meldingsord ved im-pulsrammebegyndelsen, hvilket mønster ad vejen over komponenterne IC, PG, CLT, CLR og PS indlæses i talelageret. Ved genudlæsningen bliver der ved hjælp af overvågningskoblingen 0-SM foretaget en paritetskon-30 trol. Af denne kontrolsløjfe omfattes altså ikke blot selve talelageret men også dele af komponentgruppen DIU's sende- og modtagegren.These controls are also triggered by the aforementioned overall control. They are carried out in an operating state in which no intermediary technical operation occurs by forming control loops which optionally control various components of the interface component and in addition of the component group DIU which is component of the interface component. In the case of a control comprising the voice memory, a control pattern is applied to the receive input DXI of the component IC in the receiving component of the interface component in all channels, the contents of each two consecutive pulse frames being provided with a parity bit, so that it is taken into account. frame-25 shows changes of synchronization words and message words at the pulse frame beginning, which pattern along the way of components IC, PG, CLT, CLR and PS is loaded into the voice memory. On the read-out, a parity check is performed by means of the monitoring connection 0-SM. This control loop thus includes not only the voice storage itself but also parts of the DIU's sending and receiving branch.

Ved dannelsen af en anden kontrolsløj fe bliver det kodede signal fra separate udgange TA og TB på 35 HDB3-koderen HDB3-E i stedet for PCM-strækningen PCM-0 sløj fet tilbage til indgangene DRA og DRB påUpon the formation of another control loop, the encoded signal from separate outputs TA and TB of the 35 HDB3 encoder HDB3-E instead of the PCM stretch PCM-0 is fed back to the inputs DRA and DRB at

Claims

8 Ulv Tb // 3Z bl HDB3 decoder HDB3-D. (Control Path HDB3-L). As a result of this loop control, the units HDB3-E and HDB3-C, the monitoring couplings U-AIS, ϋ-NOS, U-CRC4 and the pulse frame monitoring of the component PS 5 are also monitored for the delivery of a "good" signal, such a In each case, the looped bit stream meets the criteria to be monitored by these monitoring links.An above mentioned second HDB3 encoder HDB3-E simultaneously provides an indication signal to the PCM transmission line, which signal to the transmission on the opposite side, which can be reached over this stretch, an indication A provides that there is currently an unusual operation, namely a diagnostic operation.

Alternatively to the explained control loop, during the bypass of the encoder or the control loop respectively, decode HDB3-E respectively. HDB3-D is loop controlled, the binary signal at the OPOUT output is looped back to the OPIN input. (Control route TTL-L in Fig. 2). A method for diagnosing and controlling an interface component (FAU) for connecting a PCM-25 transmission line in a digital time multiplex telecommunication system with a transmission space in a telecommunication system which, in addition to other components, has a voice memory (SM) for temporarily adapting it to the transmission line. generated pulse frame according to the 30 pulse frame underlying the operation of the intermediary site, and in addition is equipped with a number of different criteria for the information transfer on the PCM section judging monitoring links (U-AIS, ϋ-NOS, O-DCV, U-CRC4 , U-SM), to which at least in part, error counters are associated, and which, over a computer interface (DB / CR), are connected to a separate control (DIU-C), whereby the couplings (O- AIS, U-NOS, 0-DCV, U-CRC4, O-SM) as well as back-fault error counters, voice storage (SM) and data interface (DB / CR) under the unchanged continuous best Emotional operation of the Interface Component (FAU) is subjected to routine checks to which the couplings caused by the control are affected by simulation sizes corresponding to a fault, and for the purpose of fault location and control of the Interface component 10 before commissioning or interrupted operation, respectively. Determined operation of the interface component has not yet begun, control loops are formed, characterized in that during the routine checks, in the voice storage (SM), either in each case in relation to a channel individual storage cell, the information to be loaded is provided with a parity bit and subjected to a readout. parity control (U-SM), or a bit-pattern transmitted bit pattern normally transmitted as a free-channel password, is controlled by an overall control of the transmission space after the technical blockage of the channel in question, transmitted to the voice storage cell in question and sent again back to the intermediary site, to be compared there with a real free-channel password, and the contents of the control component (DIU-C) control register (CR) ascribed by the interface component are read destruction-free and in each case compared to a should information which is below it in the event of interruption For example, as yet not determined operation of the interface component checks have been made for control loop testing of the voice memory (SM), a content of two pulse frames comprising parity checks is made. 35