DE1512902B2 - Circuit arrangement for subscriber stations in telecommunication systems, in particular telephone systems - Google Patents

Description

The invention relates to a circuit arrangement for subscriber stations in telecommunications, in particular Telephone systems to block the unauthorized generation of certain dialing codes.

In telecommunications, in particular telephone systems, the participants are according to the possible types of Connections are each assigned to a specific authorization class. For example there is the so-called Local authorization, in which certain subscriber stations from long-distance traffic, in particular from self-dialing long-distance traffic, excluded are. There is also an authorization class through which calls can be made for certain Participants who cannot be reached will be included. Obtain other types of authorization on the possibilities of automatic call charge announcement developed in newer systems or in private branch exchanges to the direct dialing option in the local traffic network.

With the different types of authorization, the respective participant also has different fees to be paid. Probably the most significant effect here is the remote voting authorization, through which it is in the In the course of the introduction of self-dialing long-distance traffic is possible by choosing a zero as a long-distance identification number Establish call connections, through which in comparison to local traffic significantly higher fees are caused.

The need now often arises for subscriber stations, which are often operated by unauthorized persons, as well as for subscriber stations in PBXs the possibility of using certain authorizations and the resulting to block increased fees, i.e. the broadcast associated with the use of special services to prevent certain dialing codes or their effect on the switching equipment.

Various dialing codes are already available to block the unauthorized generation of certain dialing codes Known solutions that relate either to measures at the subscriber station or to measures in the switching office or refer to both possibilities.

For example, mechanical devices are used to block remote dialing authorization for stations with dial dialing Facilities known that are provided in the form of a lock to be locked with a key and choosing a zero as the first dialing code prevent a series of dialing codes. It is also known that after the connection is established in the exchange incoming first charge pulse to identify the respective authorization to use. Here, however, the disadvantage arises that the switching equipment is initially for a are occupied for a certain period of time until they are released again after the unauthorized election has been determined. she are therefore not used for their actual purpose during such an occupancy.

Further known possibilities for blocking the unauthorized generation of a certain dialing code consist in the fact that the circuit used for dialing identification is in the subscriber station upon actuation of the mechanical element assigned to the specific dial indicator is switched to ineffective. This is done, for example, by short-circuiting the dialing codes generating switching element, z. B. the dial pulse contact for pulse dialing. With this bridging however, the disadvantage arises that during the time in which the digit to be blocked is dialed, the occupancy circuit is still closed and the switching equipment occupies an unnecessarily long time stay. This disadvantage is avoided in other known arrangements in that the for The circuit used for the dialing code was interrupted when the dialing code to be blocked was selected will. In these arrangements there is also a normally open contact or a mechanism for short-circuiting or latching of the normally closed contact is provided when generating dialing codes that are not to be blocked. In these solutions, however, it is necessary to use the normally closed contact, which has been actuated once in the event of an unauthorized choice by a switching measure that must be carried out by the participant himself, so z. B. by hanging up of the handset or, in the case of coin-operated machines, by inserting a coin. If a participant selects unauthorized z. B. the blocked remote elimination number, so the interruption of the circuit used for dialing identification generation. The station circuit is thus disconnected from the subscriber line, and there can be no dial tone from the exchange are received so that the subscriber is not informed of the unauthorized choice made will.

The present invention is based on the object, while avoiding the disadvantages of the known

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th arrangements a circuit arrangement for blocking the unauthorized generation of a dialing code to create, in which the participant is automatically informed of his unauthorized choice and for this purpose receives a dial tone from the exchange.

For a subscriber station circuit with a break contact to interrupt the circuit used to generate dialing codes when actuated of the mechanical element assigned to a dialing identifier to be blocked and a normally open contact for short-circuiting the normally closed contact when the dialing code that is not to be blocked is actuated mechanical element, this object is achieved in that the break contact only up to Return of the mechanical element assigned to the dialing code to be blocked into the rest position remains actuated and that the working contact in a known manner by the participant after the election Actions taken (e.g. pressing an end-of-dial button or hanging up the handset) in its rest position is brought.

In the case of an unauthorized choice, a loop interruption occurs first with the normally closed contact, the but only lasts as long as the mechanical element, i.e. a dial or a dial button, is actuated. The interruption of the loop unlocks the already occupied brokerage facilities, and after the normally closed contact has returned to its rest position, the loop closure causes a renewed occupancy. The subscriber thus receives a dial tone from the exchange, which he has to repeat Vote is requested or informed about the previous unauthorized election. Since only the one for Circuit used to generate dialing codes, for example the subscriber loop, but not the Elements generating dialing codes influenced by the inventive circuitry of the contacts the invention can be applied equally to pulse dialing and key dialing subscriber station circuits be applied.

According to a further embodiment of the invention, the contacts provided for blocking can be used Station circuits can be further designed that also a subscriber z. B. with key Contact to be actuated is provided, which short-circuits the normally open contact and the normally closed contact. aside from that A contact can be provided that connects the working or break contact and the Circuit used to generate dialing codes' 5 ° shorts. Through these key contacts it is possible Easily switch subscriber stations from one type of authorization to the other, or any choice to prevent!

In the figures are exemplary embodiments for subscriber station circuits shown, with which the invention is explained in detail below will.

F i g. 1 shows a subscriber station circuit for tone frequency key dialing formed in accordance with the invention; ■

F i g. Figure 2 shows another embodiment of a subscriber station circuit for tone frequency key dialing;

Fig. Figure 3 shows a subscriber station circuit for DC key dialing formed in accordance with the invention using the diode-earth method, and

F i g. 4 shows schematically a mechanical arrangement for actuating the normally open contact within a set of keys which is used for the circuit arrangements according to FIG. 1 to 3 is used.

In Fig. 1 shows a telephone subscriber station circuit which operates on the principle of tone frequency key selection and is equipped according to the invention to prevent the transmission of the remote elimination number zero. The speech circuit SP and the oscillator OSC are shown only as functional units, since they do not belong directly to the circuit arrangement according to the invention and their details can be designed as desired. For this reason, the coding contacts that control the oscillator and are mechanically connected to the selection keys are not shown in detail. The contacts \ tg and 2tg are contacts common to all keys, which are actuated each time the key is pressed and disconnect the speech circuit SP from the line wire a or switch on the oscillator OSC for the purpose of dialing identification. The normally open contact il-9 is closed when the selection keys 71 to 79 (FIG. 4) are actuated, and the normally closed contact is opened when the selection button 7Ö is pressed. Contacts Is and 2s are operated by a lock, with which any selection is prevented by closing contact 2s , there is no blocking by closing contact Is and in the third position shown, in which both contacts are open, the blocking of the remote elimination number is effective is. If, after lifting the handset and closing the contact .hu, the button 70 is pressed as the first button, the normally closed contact is opened and the oscillator OSC is switched off or the loop running over the wires a and b and over the oscillator OSC is opened, whereby the tone frequency signal corresponding to the digit zero is not transmitted. Through the loop opening, the switching devices occupied in the exchange are enabled again, so that after releasing the key 70 by closing the loop, a new seizure process takes place and the dial tone is transmitted to the subscriber station. However, if one of the keys 71 to 79 is pressed as the first key, the normally open contact il-9 is closed. This remains closed by a mechanical latch, not shown here, during the further selection, so that the transmission of the dial code zero is then also possible. The mechanical latching is only canceled again when the handset is placed on the device, whereby the in FIG. 1 is restored.

In Fig. 2 shows an exemplary embodiment of the circuit arrangement according to the invention in which, instead of a mechanical latch, a relay A is provided in wire a of the subscriber loop, short-circuited by the normally closed contacts il-9 and 2a. The function of the normally closed contact OK as a zero lock corresponds to that already for the circuit according to FIG. 1 described. If one of the other keys 71 to 79 is pressed as the first key, the normally open contact il-9 is opened, whereby the short circuit of the relay Λ is canceled and it responds in the loop. As a result, the contact la is closed and the contact is OK as in the case of FIG. 1 bridged, so switched ineffective. Due to the opening of contact 2a, relay A cannot be bridged again when the button is released and contact il-9 is closed. Thus it remains during the long

ren signaling in the addressed state, so that in the course of the further connection setup, the dialing code corresponding to the digit zero can be selected. When the handset is hung up, the contact hu is opened again, causing the relay A to drop out. Of course, it is also possible with this circuit arrangement to provide a lock which, as in the case of the FIG. 1 circuit shown locks the entire subscriber station for any choice or only for a remote elimination sign by actuating various lock contacts.

F i g. 3 shows an exemplary embodiment of the circuit arrangement according to the invention for a subscriber station circuit which works with key selection according to the principle of the diode-earth method and in which the blocking of the remote elimination number zero is possible. The common key contacts \ tg and 2tg are used to switch off the speech circuit SP from wire a or to connect a combination circuit formed in a known manner from diodes Di to D4 and dial key contacts tk to the earth line E each time a key is pressed. As in the case of FIG. 1, the working contact f1-9 is held in its working position after its actuation by mechanical latching until it is ended by placing the handset. It is easy to see that when you press the TO button as the first button after lifting the handset, the contact tO is opened and a dialing code transmission via the earth line E and the two wires a or b is prevented. However, if one of the keys Ti to 79 is pressed as the first key, the contact il-9 is closed and bridged, due to the latching during the entire further dialing signal transmission, the contact OK, so that the dialing code corresponding to the zero is then also sent out can. The contacts Is and 2s are contacts of a padlock. In the case shown, the contact 2s is closed and the station circuit is blocked from sending a zero as the first digit. If contact 2s is also closed, the entire circuit is not blocked, if contact 2s is open, any selection is impossible.

The in F i g. The mechanical arrangement shown in FIG. 4 is used to actuate and latch the working contact il-9 through one of the buttons 71 to 79. The status of the arrangement when the handset has already been lifted is shown schematically. If one of the selector keys 71 to 79 is depressed in this state, the slide N is shifted to link ^{1 in} addition to the actuation of the selector key contacts (not shown) to generate the selector indicator, which closes the normally open contact il-9 and by means of the latching elements K and L causes! Latching of the slider N on the upper Kontaktfe which is held in its working position until the slider is brought to its rest position again to the right by placing the handset and actuating the reset lever M associated therewith. In the case shown, the grooves provided in slide N are designed in such a way that its movement can only be achieved by depressing the keys 71 to 79, but not. Key 70 is possible. Any other form of these grooves that enables other dialing codes to be blocked is also conceivable.

The Ausführungsbeispieh described above show the universal applicability of the fiction according circuit arrangement for subscriber stations with audio frequency and DC key selection. Ii The stations used are mostly key sets in which reserve contacts are not used are provided, the implementation of the measure specified by the invention in a simple manner men can serve. However, an application of the invention to subscriber stations mi is also possible Impulse dialing possible, with one similar to sliding; AZ (Fig. 4) formed arrangement by the num When the elevator is lifted, it is moved into the position corresponding to the dial number to be blocked. Of course, relays can also be used instead of a mechanical arrangement Locking devices are used.

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Circuit arrangement for subscriber stations in telecommunications, in particular telephone systems for Blocking of the unauthorized generation of certain dialing codes, with a normally closed contact for Interruption of the circuit used to generate the dialing code when the one is actuated to be blocked dialing indicator assigned mechanical element and a normally open contact for short-circuiting the normally closed contact when pressing the dialing code that is not to be blocked associated mechanical element, characterized in that the normally closed contact (/ 0) only until the return of the mechanical element assigned to the dialing code to be blocked (7D) remains actuated in the rest position and that the normally open contact (/ 1-9) in a manner known per se by actions taken by the participant after the election (e.g. pressing an end-of-election button or hanging up the handset) is brought to its rest position. 2. Circuit arrangement according to claim 1, characterized in that a further from the subscriber z. B. by key operated contact (Is) is provided that the normally open contact (/ 1-9) and the normally closed contact (/ 0) short-circuits. 3. Circuit arrangement according to claim 1 or 2, characterized in that a further from the subscriber z. B. by key operated contact (2s) is provided, which is located in the circuit used for dialing code generation series connection of the normally open or normally closed contact (il-9 or / 0) and the device used for dialing code generation (OSC; Di to D4, tk) shorts.