EP0166738A1

EP0166738A1 - Transmission control unit for controlling transmission networks

Info

Publication number: EP0166738A1
Application number: EP19840904140
Authority: EP
Inventors: Alexandre Latour
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-12-09
Filing date: 1984-11-20
Publication date: 1986-01-08
Also published as: JPS61500643A; AU3670284A; FR2556533A1; WO1985002739A1; FR2556533B1

Abstract

L'invention permet les opérations de diagnostic et de maintenanceà partir d'un centre unique (1) qui dispose des données d'analyse,de contrôles et de commande. Les fonctions réalisées par l'automate sont de transmettre: l'état des fonctions d'un autocommutateur; l'analyse des scénarios de communications (3) (4) (5); les résultats des mesures de circuits et de modifier les fonctions d'un autocommutateur. Le fonctionnement est automatique ou manuel selon le degré de gravité effectué à l'évènement et ceci quelque soit l'ensemble conjugué de la parole et des données pris en surveillance par l'automate.The invention allows diagnostic and maintenance operations from a single center (1) which has analysis, control and command data. The functions performed by the PLC are to transmit: the state of the functions of a PABX; analysis of communication scenarios (3) (4) (5); the results of circuit measurements and to modify the functions of a PABX. Operation is automatic or manual depending on the degree of severity carried out at the event and this regardless of the combined set of speech and data monitored by the automat.

Description

AUTOMATED DECONTROL OF TRANSMISSION NETWORKS

The present invention relates to an automatic control system for transmission networks in a remote diagnosis and remote maintenance set:. (E.T.T.D.) Terminal equipment for data transmission at a bit rate less than or equal to 19.2 k bits / s. (E.T.C.D.) Terminal equipment for data circuits at a bit rate less than or equal to 19.2 k bits / s. electronic telephone exchanges. specialized transmission links. This automaton is the element which captures incidents on a remote site that we want to supervise and which transmits them to a maintenance center. It performs cyclic tests and compares the results. The control automaton makes it possible to centralize information on the state of the transmissions and the equipment connected to it. All the elements likely to help with the maintenance and repair of the equipment (or) of the circuits of transmission are transmitted to a remote maintenance center. The purpose of this center is to record incidents, to process them so as to provide statistical data, but also to provide maintenance technicians with the elements necessary for rapid and precise intervention. This increased efficiency will lead to an improvement in the quality of the services provided by the data processing and / or telephone installations. It will follow comfort in operation and profitability of maintenance operations.

CURRENT STATE OF THE ART

A - Current telephone maintenance It is carried out piecemeal on the equipment when one or more users of the same exchange perceive a deterioration or an interruption in traffic. This perception can take place, and this is often the case, when an entire beam is disturbed.

The maintenance personnel are not always the right ones and when the right operator is selected at the right time, the equipment diagnosis poses other problems (availability of control equipment, change of circuits, modification of subscription classes ... ) The telephone exchanges of the current generation have automata that help with maintenance (Automatic line test robot - RELA). We note that RELA are only planned on large capacity exchanges (several thousand subscribers). They require a human presence, yet this skill can be used by several medium and low capacity exchanges. This is the main purpose of this patent.

B - Current IT maintenance This maintenance calls for a very wide variety of instruments (recorders, simulators, controllers, level meters). It requires a method adapted to each of the large networks. Generally a team is responsible for initiating maintenance operations and this team is led by "a network man". It has significant resources which will make it possible to take measurements requiring long operations from the farm. This inadequacy can be seen on all major networks. It results in service interruption time on a user terminal. These values related to the network opening time is the availability rate, the extremes of which are 0.99 to 0.70 in the short term. The monitoring by the PLC of certain network nodes will allow a maintenance system separate from the operation. A quick and refined diagnosis will be obtained with a trace of the shortest incidents such as micro-interruption of the data transmission circuits.

C - Transmission of voltage states This technique is not new, the automaton performs this operation without it being its vocation. Its role is to control these states and to transmit them only if their chronology or their levels are not those expected. This information is a necessary complement to the knowledge of the environment of telephone and data processing equipment. D - Maintenance of circuits in the current state of technology.

Maintenance is done at the express request of a subscriber who signals to the administration, the interruption or degradation of the service provided by the transmission medium. The interruption is a phenomenon quickly diagnosed while the degradation of the service is less so because its consequences remain diffuse and modify the operating yield.

The PLC in these functions will control the distortions of the test signal between two rests on the circuit. Degradation is therefore known instantly and reported to managers PREAMBLE

The diversity of communication techniques, the integration of services, the decentralization of resources and the multiplicity of locations are all factors that have contributed to the increase in the costs of upkeep and maintenance of the networks.

On the other hand, all of the techniques used require skills that can no longer be required of a single specialist. The automaton, object of this patent, is one of the tools which will allow a team to carry out from a main remote maintenance center: - Diagnosis of breakdowns,

- Statistical treatment of incidents,

- First level commissioning and troubleshooting of equipment,

- To publish results on the quality of service criteria. - Remote maintenance of electronic telephone exchanges.

OBJECTIVE OF TELEMAINTENANCE

The aim of remote maintenance is to reduce the costs of breakdown and maintenance operations for a communication network, while improving the quality of the services offered. It is based on:

- rapid and precise knowledge of anomalies that occur at different levels of the communication chain,

- the implementation of the means specific to the recovery of each breakdown,

- statistical knowledge of breakdowns that affect each element of the communication chain.

THE DIAGNOSIS

The diagnosis of a breakdown must be carried out quickly in order to trigger, as quickly as possible, the breakdown operations, but also, it must be clear and precise, so as to displace only the necessary and appropriate skills to deal with the fault. To do this, all incidents are centralized and managed by a single authority, available at all times and which has sufficient means to record events, interpret them and trigger preventive or curative maintenance operations. ORGANIZATION OF A TELEDIAGNOSIS AND TELEMAINTENANCE SERVICE (Fiq.1) Remote maintenance is organized from an incident management center which receives, from all user sites, information defined in advance and whose value changes will be analyzed . The incident management center has the means to:

- receive and recognize data received from remote sites,

- to address the suspected site,

- check the status of the indicators,

- to launch a test on the "Tests" access interface. Each event in the center is recorded and displayed on a logbook. The manager of the maintenance center organizes the technicians' trips, based on the incidents collected, the nature of the fault, the availability of the components necessary to correct the fault. It is therefore very selectively that the tasks of remote maintenance are assigned.

THE MESURES THAT TOOK PLACE

The remote maintenance network includes 1 set of hardware and software, which make it possible to remotely diagnose faults in a primary network, of the telephone or data or mixed transmission type.

Remote maintenance is based on the dynamic analysis of the state of a communication, as well as on the knowledge of the environment surrounding the equipment of the primary network. In essence, information that deals with the state of the primary network will not use the same transport circuits as this, at the risk of losing both the use of the primary network and knowledge of the failure. . The media used will be either: - The general telephone network of the Postal Administration and

Telecommunications.

- A private telephone network.

- A leased transmission network, consisting of independent circuits or by secondary transmission channels. The elements that go into making up the remote maintenance network are state transmitters, installed near the bodies to be controlled, communication circuits and an information management center. The organs to be checked can be very diverse in nature: PABX 8, Data Transmission Terminals 53, Modems 33 Hubs 13, Controllers or Multiplexers 35.

In all cases, we can observe the climatic conditions, the primary and secondary energies distributed, the access rapes and, more generally, the environment of each of the organs.

THE TELEMAINTENANCE CENTER (Fiq. 2)

The main remote maintenance center consists of:

- a central unit 56, managing communications with remote sites equipped with remote diagnostic means

- a set of links, connecting the remote sites to the remote maintenance center 51, permanently or temporarily, depending on the reliability criteria of the set to be maintained

- a file 18 on discs of the incident recording - a logbook printer 21 which provides the maintenance team with the nature of the faults, the time stamping of the incidents and the address in plain text, disrupted sites, the timestamp of the restoration of services

- terminals 52 which will allow dialogue with the remote maintenance system.

This supposes means of communications addressing remote sites

- back-up sources of energy 3 making it possible to collect calls from remote sites around the clock

- an IT link with the managers of a network or a person authorized to know the state of the network.

One of the special features of the remote maintenance system is that it has a synoptic table 48 which can be transferred to the premises of a customer. This table receives, from supervised sites, the states "Major Alarm or Minor Alarm" and the indication that these states have or have not been recorded at the main remote maintenance center. At the central site, the time-stamped event is recorded on paper, then stored on disk in an ui format allowing statistical processing to be carried out cyclically.

REMOTE SITES

Remote sites are equipped with a standalone whose functions are:

- Recognition and memorization of a minor event,

- Recognition and memorization of a major incident,

- Management of incoming calls, either on dedicated links, either on dial-up telephone connections.

- Management of outgoing calls that can alert two different centers, to guarantee the successful completion and consideration of serious events by at least one decision site, - Analysis and verification of compliance with one or more scenarios of transmission recorded in PROM. Failure to respect the scenario causes the incident to be transmitted.

N O T A: The particularity of this automaton is that it can both:

- Receive information and transmit it

- Orient incoming communication to a line adapter, connected to the system to be monitored. The central remote maintenance site can then, from a distance, converse with the remote maintenance unit. - Adapt to different scenarios specific to data processing, or telephone exchanges.

PRESENTATION OF THE TE PLC 1

TE 1 in Teleinformatics (Fig. 3)

The PLC is transparent to the transmission procedure and to the codes. Depending on time slots, it assigns a telephone link to the supervisory body alone, or to the data transmission terminal. This access to teleinformatics is limited by the use of the national switched network.

The transmission mode is asynchronous at 1200 Bauds in half-duplex. The transfer loss is zero between input and output. This standardized access allows, from a maintenance site, to send a test transaction to a data processing terminal or to a transmission chain. This transaction will receive a response in case the assembly is correct.

The TE 1 receives one or two interfaces which allow the simultaneous analysis of 8 to 16 V 24 junctions. The signals are captured in parallel on the high-impedance operation so as not to create disturbance or interruption of the operation in supervision system malfunction.

Annex 1 gives the supervised communication scenario. The controller can analyze five different scenarios. The RS 232 ports will allow the signals from the terminal junctions to be analyzed:

- Either dynamically for fixed signals 105 -106 ...)

- Either dynamically for variant signals up to 19.2 Khz (103 - 104 ...)

- Or for all of the data processing signals. The terminal environment is supervised by entering the signals available on the machines or created nearby by additional bodies (Temperature - Energy - Fire - Access ...). Voltage levels are those compatible with T.T.L. There are 72 of them for the basic version. An extension card can be adapted to this version if 72 additional states are to be processed. The T.T.L. can be transformed by optoelectric interfaces which limit to 72 the number of supervisions. The maintenance center can assign a dynamic count of minor incidents that occur on a data processing link. Thus, for example, the supervision of the wire 109 shows the micro-cuts of the lines. This incident is generally minor and therefore transmitted during interrogation by the maintenance center. However, a large number of interruptions introduces a degradation of communications. The allocation of the event counter will allow the measurement of the error rate as follows:

Number of micro-breaks Number of bits / s Reading time - Triggering time

TE 1 in Telephony The TE 1 PLC allows, in telephony, to deport the alarms produced locally by the telephone installation. The telephone exchange of recent generations has an interface which allows a man-machine dialogue. This dialog is deported to the maintenance center so that remotely, the tables of anomalies will be consulted and the programs modified on request.

The TE 1 automaton outside these applications performs a cyclic reading of the PABX tables and in the event of a serious event that the operator of the maintenance center will define, it triggers the numbering and the transmission of the incident. For minor incidents, the automaton records them and announces them either periodically according to a programmed cycle or at the time of an interrogation of the maintenance site. TE 1 in Telemetry of PRINCIPE transmission circuits (Annex 2)

Characteristic frequencies must be generated cyclically at the address of a receiving end in order to know the amplitude variations provided by the line.

The test of this circuit will be made in operation for a very short time which should not cause discomfort for the user. An elementary test time is approximately 150 ms with a recurrence of a quarter of an hour or half an hour. The frequencies transmitted are included in the voice band.

The frequency combinations have a one-to-one relationship with a binary code stored in reprogrammable memory.

These combinations will be issued in groups of three or four to speed up the test cycle. The level of the circuits to be measured is from -40 to 0 db in data processing. The accuracy of the measurement is given by the number of steps "p" emitted db ≠ 6 db or by the analysis on reception of a finer part of the dynamics, ie for example db ≠ 0.8 db which will allow a conversely, a very small variation around a known level. A code is transmitted online at a given level which is specific to it.

Do not, for example so that the receiver which has a sensitivity "S" will interpret the values of level Nr ≥ S with Nr = the attenuation / α / - / Nc / of line

In addition, the receiving end has an automaton whose role is to check the values received on a set of lines, that is to say that each must find a frame consisting of a series of codes.

1 - 2- 3 - 4 - 5 - 6 - 7 - 7 - 7 At the interruption of the suite is located the level

Nr limit that the user wants to know This measurement will be done on ten lines simultaneously.

The TE 1 in surveillance and access control (Fig. 4) The TE 1 PLC does not have the essential vocation of transmitting alarms although its constitution allows to solve the problems of 13 remote alarm.

The machine has interfaces that allow you to read badges or perforated encoded cards. These codes are read by parallel readers which supply the code pulses and the signal for loading data into the management card.

When a reader is active, it forces the busy line which prevents any other reader on the line, the possibility of access. Thus, a badge reading interface may require ten points from the management card. It will therefore be planned to connect both badges to a TE 1 and to provide, after the code validity test, access validation information in a building or in a room. The list of numbers accredited for access to the building or to the premises is known only from the central site.

There is therefore an exchange of information with the central site before validating access to the building. This precaution is a guarantee of security and leaves the operator the possibility of instantly modifying the list of accredited persons. This assembly can receive an image-by-image transmission system connected through access V 24 of the TE 1 automaton and in this case, the center operator has a receiver that will allow reception of the image Applicant's video.

It is then noted that this receiver can be allocated to several applications.

PRESENTATION OF TE 1 - (Fig. 5)

The TE 1 state transmission automaton is in the form of a box of 2 units high (10 cm approx.) And 19 inches. The depth is 40 cm. The electronic equipment, installed in this box, can be put in a telecommunication bay of the same standard 19 inches. These equipments include:

- Interface cards of two types:. V 24 interfaces - a card has 8 ports

. TTL Interfaces - one card has 72 accesses. Telemetry interface

- a management and line interface card

- a main power supply of 220 Volts - An optional backup battery

- On the front panel are the On - Off controls and the Line seizure indicators - Call - Smission and Reception

- On the rear side, all the connections are made to the mains supply through a grommet Arrival of V 24 junctions on 9-point connectors

Arrival of monitored points in TTL. This equipment can be optionally fitted with optoelectric interfaces added to the basic version, to provide 32 access points electrically isolated from use.

THE FUNCTIONS OF TE 1

The standard TE 1 equipment which equips a station aims to:

- Trigger two calls on the telephone network in the event of damage or a serious incident in the environment of the equipment.

- Respond to requests from a maintenance center responsible for knowing the state of the equipment, its environment and traffic.

- To repeat the calls to a telephone number for remote maintenance, then to a number in the operating room of the computer systems.

- To allow, with a remote maintenance center, the visualization of the state of the equipment and exchanges in a transmission network. This equipment will be used on dedicated or switched links. SIMPLE OPERATION OF TE 1

TE 1 link to Remote Maintenance Center on switched network. When a situation change is made on the PLC accesses, the microprocessor takes it into account. When this event occurs on an access reserved for "Major Alarms", the PLC causes the line to be taken and manages the establishment of communication. It causes the emission of a telephone number registered in PROM: this number corresponds to the remote maintenance center. When the center responds, the line adapter detects it, signals it to the microprocessor and communication is established. When the telephone exchange returns the occupation or the remote maintenance center is occupied, the microprocessor makes other attempts, then changes the number to alert a different center. He then indicates the causes of his call and indicates that the previous number was not contacted. The messages exchanged are short and if, however, an exchange should exceed the time of 1.5 seconds, the link would be broken by the remote maintenance center.

If the transmission was correct, the remote maintenance center notifies the PLC and breaks the link. Otherwise, he asks repeating the message.

CONNECTION PROCEDURE

We analyze in this paragraph, the various methods allowing to establish the physical connection between the main station and the TE 1

A - The calling TE 1: (use of the switched network) At the start of this phase, the TE 1 arms a T ∅ at 120 s. This will be disarmed by the remote maintenance center at the end of the shift. It prohibits any line occupation greater than 120 s. (time estimated sufficient to carry out the exchanges in good conditions). In fact, if the T ∅ has not been disarmed and is expiring, this means that the vacation went wrong (communication impossible to establish: transmission disturbed by errors involving too many repetitions, etc.) .

It causes the line to be released by the remote site. Then the remote site takes the telephone line. It waits for the presence of 420 Hz for 15 s (this signals that the exchange has recorded the line seizure and prompts to dial,), - If 420 Hz appears, we test its presence again for

1.5 s.

- If after 15 seconds we have not been able to obtain the confirmed 420 Hz, we hang up for 10 seconds. The appeal procedure can then be renewed. - If 420 Hz is confirmed, the remote site dials and arms a T secondes of 30 seconds. This "time out" will be disarmed as soon as the remote site has received a message from the remote maintenance center. If the T ∅ expires, this means that the numbering has not been correct. The line is rendered and we wait at least 5 seconds before trying to dial again.

NOTE: To prevent the remote site from constantly calling when its call cannot be completed: CEA is set to 5 in the initialization program. It will be decremented by 1 each time the remote site initiates a call on the switched network; it will be reset to 5 each time the remote site receives an ACK message. After dialing, the detection of a 420 Hz outage for more than 10 s results in the line being released. Indeed, such a cut signals the occupation of the requested number. After these attempts if the number of the remote maintenance center is not still not obtained, TE 1 makes an attempt on a second number. This number could correspond to the customer's computer center or to that of the remote maintenance manager. APPENDIX 3 - Test counter.

B - The TE 1 called (use of the switched network) The reception of a call coming from the general switched network creates an interruption of the program in progress and causes the telephone line to be taken. If no data arrives within an adjustable period (on average 3 seconds), the line is released.

C - Use of dedicated lines In this case, all TE 1 substations are physically permanently connected to the central station which interrogates them cyclically. In order to allow exchanges, all of the TE 1 substations are in reception and analyze the addresses sent by the central station and only respond when the address received is the same as that assigned to them. Their number will be voluntarily limited to 100.

COMMUNICATION PROCEDURE A - GENERAL

The communication procedure meets the following characteristics:

- The remote site never sends a message by itself: it only responds with a RESPONSE message to a REQUEST message sent by the remote maintenance center. - The remote site only sends the response message when it has received a fully correct REQUEST.

- The remote site does not have to interpret the order of succession of REQUESTS. Each REQUEST elicits a specific response.

- After each transmission of a RESPONSE message, the remote site hangs up, if it has not received a new correct REQUEST from the remote maintenance center within 5 seconds (in RC only).

- The reception by the central station of a call from a TE 1 (switched network) causes the sending of an unmarked request, that is to say with a station number equal to 0. B - CODE OF TRANSMISSION

The transmission between the central station and the TE 1s will be carried out at 1200 bauds, according to the following code:

- 1 start

- 8 data bits - 2 stops

- link possible in half-duplex

C - MESSAGES REQUEST

They are sent by the remote maintenance center to TE 1. They are made up of 4 bytes:

NSTAT It is the number of the station when it is known to the remote maintenance center (case of LS and requests other than the first addressed by the remote maintenance center connected to TE 1 by the switched network), or it is an unmarked number recognized by any TE 1 connected by RC, during the first REQUEST sent (indeed, the center does not know the number of the site that calls it). Supplement to 1 of NSTAT. CDE Order value; we will find the following commands:

- POOL: the remote maintenance center asks the remote site if it has a message (used mainly for polling TE 1 on a dedicated line).

- VAL CDE: The operator who validated the order the remote maintenance center advises the remote site that the order must be applied. The site will respond by giving the result of this application.

- CANCEL: The operator canceled the order he had requested. The remote site cancels the order - It responds as for VAL CDE

- STATUS: The operator requested the status of the remote site. This responds by sending its status (see below).

- ACK: Positive acknowledgment by the remote maintenance site of the text message sent by the remote site. : complement to 1 of CDE

D - RESPONSE MESSAGES These messages are sent to the remote maintenance center by the TE 1s in response to the request messages. Message format:

NSTAT station number T: complement to 1 of NSTAT REP: see above: complement to 1 of REP

C∅: text byte count (see NOTE 1 below)

TEXT: text, ie content of the counters, value of the states which have changed or state of the remote site This text may not exist (in the case C∅ = 0)

LRC: odd longitudinal parity character calculated over the entire message, from NSTAT included to the last character of text included.

The REP values:

They are dictated by the request received and by the state of the remote site at this time:

NOTE I: The values of C ∅

C ∅ is equal to the number of text characters in the case of a STATUS response

Last 5 bits: number of states transmitted.

Organization chart: see figure NOTE II: Specific actions on some requests

- CDEi: TE 1 stores in memory the two bytes CDEi and CDEi

- CANCEL: TE 1 erases in memory the two bytes CDEi and CDEi

- VAL CDE: The TE 1 tests if it has the CDEi and CDEi information in memory, if these are valid (existing command (CDE) = (CDE), it applies the command, reads the value of the commands applied, checks that the command has been successfully applied. If this is not the case, it starts again 3 times before sending "command impossible" to the remote maintenance center.

- STATUS: TE 1 reads information from the states CDEi possible: we will find:

- 7 external walking controls

- 7 external stop commands

- RESET

- TE 1 standby (it takes the states into account but does not transmit them).

- Return to activity of TE 1 The status of TE 1

It comprises :

- the station number (transmitted in NSTAT)

- the value of the remote controls applied (option)

- RC / LS information

- registered telephone numbers

- the number of states wired in TE 1 - the value of all states

- the communication scenario present or expected on the V 24 accesses

FUNCTIONAL ORGANIZATION OF TE 1 TE 1 is organized into four modules. The purpose of this cutting is to separate the different functions of this assembly and to allow commissioning and relief of rapid faults. Furthermore, this equipment can be suitable for several different applications and therefore the transformation of the interfaces must be easy.

This equipment consists of:

- a microprocessor and modem card

- two V 24 state management cards

- two TTL state management cards - a line telemetry card

- a 220 V mains power source

- a backup power source

Figure 5 gives us a presentation view of the whole.

THE MICROPROCESSOR AND MODEM CARD GENERAL: It aims to provide links between TE 1 and:

- TTL state management cards

- V 24 junction state management cards - RC / LS transmission line

- the maintenance terminal at 300 bds

- the 1200 bds data processing terminal It allows:

- manage telephone communications - decide to send a message to the remote maintenance center

- to read the states present on the management cards

- compare the states read with those of the saved tables

- compare the states of a communication with those expected

- answer a call from the remote maintenance center.

THE STATE MANAGEMENT CARD V 24

GENERAL:

The management body establishes the relationship between the information taken from the V 24 junction of a terminal and wired to a terminal block and the "micro and modem" card. She permits :

- reading in TTL form of the main V 24 signals with fast variation (up to 19.2 Kbits / s) - reading in TTL form of the main V 24 signals with slow variation.

- the transformation of a bivalent signal into a TTL voltage compatible with the core of the system.

- high impedance data entry so as not to modify the operation of the terminals.

THE GENERAL TTL STATE MANAGEMENT CARD

The management body establishes the relationship between the information taken from terminals or the triggering of alarms (intrusions, temperatures, pressure, energy, etc.) and wired to a terminal block and the "micro and modem" card. She permits :

- TTL reading of TTL signals or dry loops whose variation will be slow (of the order of a ms)

- high impedance data entry in order not to disturb the sources of the analyzed signals.

- transmission to the "micro-modem" card in TTL of the states taken from the terminal blocks. LINE ADAPTATION FUNCTION A - GENERAL This purpose of the micro-modem card is:

- ensure the interface with the telecommunications network (digital analog transformation). - to dial, under the control of the management card, to allow the connection TE 1 - main station.

- answer a call from the general switched network (initialized by the main station), under the control of the card.

B - OPERATION The diagram in figure 6 gives the detail of the line interface The diagram in figure 7 gives the spectrum in lines. Two specific cases are analyzed in detail below:

- sending a call: on command of the management card, the line interface card operates as follows (see diagram on page next).

- The reception of a call: this call is timed by a circuit which switches the line relay on the input transformer. If after the time delay of 10 + 20 s (adjustable) no data arrives, the line relay drops out awaiting a new call. On the other hand, in the case where a datum is received, the DS signal is in automatic maintenance of the line relay, which authorizes the fallout of the call signal. The DS light is on on the front of the unit as well as the IA light. The signal received from the correspondent is routed through the duplexer and the reception filters.

These filters are of two kinds. One or two amplifier and filter stages are switched to obtain a constant 0 dB level on the second filter. Out of the filters, a zero detector stage provides a perfectly cyclic signal. The signal is then amplified to obtain the steep edges necessary for the demodulation circuit. The filter circuits are of the active type. On reception after switching of the received frequency group, two filters, each with a gain of 25 dB, are switched in cascade in order to tolerate reception at low level (-50dB) or high level (0 to -25 dB). IMPLEMENTATION

Perform the RC or LS command depending on whether you want to operate on a dedicated line or on a switched network. Using the maintenance and commissioning terminal, save the system parameters.

- number at TE 1

- telephone number of the remote maintenance center

- telephone number of the rescue centers TECHNICAL CHARACTERISTICS

Common supply 220 volts 0.25 A

Low voltage supply ± 12 volts + 5 volts

Modulation speed I 200 bits / sec

Emission frequencies I 300 Hz 2 100 Hz

Tolerances ± 10 Hz

Spectrum emitted online width at 3 dB: 1,100 Hz to 2,300 - useful bandwidth: 900 to 2,500 Hz

Transmission level 0 to - 15 dB Reception level 0 to - 42 dB Mismatch <20% ANNEX 1 -

GENERAL ANALYSIS OF JUNCTIONS

The computer outputs of the junction patching system are connected to a monitoring system which analyzes the changes in polarity of certain wires (108, 106, 103, 104, respectively Data terminal equipment ready - Ready to send - Signal detector received on the data channel - Data reception) and deduces 4 operating states of the common core:

State 0: the line was not initialized by the computer operator,

State 1: the line has been initialized but no terminal has yet responded, State 2: the line has been initialized and at least one terminal has already responded; on the other hand, polling does not take place correctly. This case corresponds to an incident on the link during operation. State 3: the line has been initialized; polling is effective on the line which is in normal operation. States 1, 2, 3 are displayed on the monitoring system by LEDs of different colors (1: orange - 2: red - 3: green).

State 0 is displayed by the fact that all the lamps are off A junction is analyzed by a track card of the surveillance system which has the three indicators mentioned above, these indicators memorizing the appearance of states 1, 2, 3. A group card centralizes the information provided by 16 channel cards, in two possible operating modes, selected by a switch on the group card.

Mode 1: States 2 and 3 are displayed in real time, as they appear. Mode 2: State 2 is maintained from the moment it appeared. This mode makes it possible to "trap" fugitive faults. Each channel card has the possibility of not transmitting the mode information to the group card. TE 1 analyzes the following V 24 junction wires: - 103 Data transmission

- 104 Receiving data

- 106 Ready to send

- 107 Data station ready

- 109 Detector of the line signal received on the data channel. Dynamic monitoring

The analysis of wires 104, 106, 109, 108/2 makes it possible to define the conditions necessary for the elaboration of the states described below. These are memorized when they appear until the next reset which acts on all conditions.

See Annex 4

Time setting

On each channel card, it will be possible to set timers of 0, 4, 96, 112, 120, 124, 126 seconds on circuits 109.

A N N E X E 2 -

RECEIVING TELEMETRY SIGNALS

PRINCIPLE:

On the circuit to be measured are present signals of variable amplitude whose frequencies are known and, these frequencies considered in groups, constitute a one-to-one association with a code of decimal type which we know in advance, the finite sequence.

Thus the line telemetry signal receiver will decode the sequence and compare it to a table of expected codes. The first missing code combination will identify the line loss level.

Ten separate receivers are sliced on the lines to be measured.

They are managed by an external body which will read in series all the values received and sampled in parallel. To do this, the measurement values will be stored in memory with an additional bit which will indicate whether the received word corresponds to a data or not.

All these data will be read in parallel on an order communicated by the external body and shifted in series to the rhythm of a clock, which is also supplied externally.

The read order will have a period of a few milliseconds and will be a 20 us pulse.

The data shift clock will be 20 us.

Use of memory 2716 (1024 x 8 bits) This memory will receive the addresses of a register generating the 1024 states without interruption.

Ado Ad 1024 Ado etc

In these addresses the programmed codes are located equidistant in order to define zones of silence which will correspond to: - the frequency separation - the recurrence of the tests

To generate three frequencies (7 combinations + 0) we will use 5 memory zones.

(See Annex 5)

Tests 1 and 2 are spaced 15 to 30 minutes apart, or 336 addresses to 000 ... explored in 15 or 30 minutes.

This implies not performing 336 steps but N times 1024 after the test x - 1 to start the test x.

This condition is fulfilled by the inhibition of the N test x +2 and x +3

FIGURE 1 - Remote Diagnosis and Remote Maintenance Service

FIGURE 2 - Remote maintenance center

FIGURE 3 - TE 1 in Teleinformatics

FIGURE 4 - Building access control

FIGURE 5 - TE 1 assembly FIGURE 6 - Line interface

FIGURE 7 - Spectrum online

- APPENDIX 1 - General analysis of junctions

- ANNEX 2 - Reception of Telemetry signals

- APPENDIX 3 - Test counter - APPENDIX 4 - Dynamic monitoring

- APPENDIX 5 - Memoir 2716 with 7 combinations

NOMENCLATURE OF FIGURES

1 Adaptation of the numbering

2 Referrals

3 Back-up power

4 Display

5 Agency

6 Appeal

7 Stop

8 Electronic branch exchange

9 TE 1 controller

10 Calculations

11 Technical center

12 Orders

13 Concentrator

14 System console

15 Call detection

16 Tone detection

17 Program

18 File

19 Front

20 Keep

21 Printer

22 Incident

23 Interfaces

24 Invitation to dial

25 Invitation to issue

26 Logbook

27 Badge reader

28 Release

29 Tap line 30 steps

31 Masking

32 Coded measures

33 Modem 34 Motor

35 Multiplexer

36 Numbering

37 Computer

38 Line seizure

39 Central processor

40 Management processor 41 Protection

42 Reception

43 PTT line distributor

44 Telephone switched network

45 Signals

46 Simulator

47 Supervision

48 Synoptic table

49 Remote control

50 Telephone

51 Remote maintenance

52 Master terminal 53 Consultation terminal

54 Tone test

55 Line transformation

56 Central maintenance unit

57 Visual consultation

Claims

R E V E N D I C A T I O N S

1) Transmission network control automaton characterized in that it comprises interface cards (23), a management card (40), a modem (33), powered by back-up equipment (3 ). This assembly allowing the control of each user center by a remote maintenance center, the said remote maintenance center being backed up by a synoptic table (48) being composed of a central maintenance unit (56), of an instructed file (18) by an operator using a terminal (53), a master terminal (52) diffusing the results on a printer (21), transcribing the incidents perceived by the user centers on a logbook (26), the said incidents being stored in concentrators (13) managing communications through the automata (9) connected to the lines leading to the distributor (43).

2) Network control automaton according to claim 1, characterized in that it comprises a management card (40), a modem (33), a power supply (3) on the card (40) an opto-electric coupling and a junction V 24 allowing connection to modern electronic exchanges, this automaton located in telephone user centers, scans for anomalies by triggering the call and instructing the maintenance center, with a date-time group added to the analysis of the anomaly, the said center being able in turn to dialogue with the central by calling the automaton, this making it possible to modify the classes and categories of the stations remotely, to periodically record the telephone consumption, station by station or by service , the memory of the PLC management card comprising all of the dialogue expected from the automatic exchange, in order to be independent of each type of automatic exchange. 3) Network control automaton according to claim 1 characterized in that it comprises a management card (40), a modem (33), one or two V 24 interface cards (23), the so-called cards (23) being powered by back-up equipment (3) and the capacity of each V 24 junction interface card (23) being 8 junctions, i.e. a simultaneous analysis of 16 junctions and the memory of the management card ( 40) being downloaded by the remote maintenance center describing junction by junction the signals expected by the modems (33) and the front ends (19) or the modems (33) and the concentrators (13) or the modems (33) and the multiplexers ( 35). At each change of a serious or de ned event as such, by the remote maintenance center, the automaton transmitting its analysis with the date-time group.

4) A network control machine according to claims 1, 2 and 3 characterized in that it comprises interface cards (23) of V 24 signals controlling 144 electrical states, a management card (40), d 'a modem (33), said cards being powered by back-up equipment (3), the automaton installed in telematics user centers making it possible to control the states of 16 V 24 junctions implementing analyzes by controlling the environment , at each appearance or disappearance of a state that the remote maintenance center considers serious, the machine describes the state by adding the date-time group of the event.

5) A network control machine according to claims 1 and 4 characterized in that it comprises a management card (40), a modem (33) managing one or two interface cards (23) with telemetry functions converting analog measurements in digital signals understood as a set of electrical states, the automaton transmitting the digital values to the competition of 144 states organized in significant groups.

6) Network controller according to claims 1 and 5 characterized in that it comprises an interface card (23), a management card (40) of a modem (33) of a backup power supply (3 ) constituting an access control automaton making it possible to read up to four badges simultaneously, by transmitting the readings to the maintenance center, offering the holder of the badge the possibility of accessing or not a protected site, the center carrying out for this purpose a remote control addressing the interface corresponding to the badge reader.