DE2556419C2 - Circuit arrangement for dialing control in telephone systems with location and remote time counting, in particular for private branch exchanges connected to such systems - Google Patents

Description

The invention relates to a circuit arrangement for dialing control in telephone systems with local and Remote time counting, especially for private branch exchanges connected to such systems in which all or certain groups of participants are generally excluded from participating in long-distance connections are and the attempted remote connections of such participants by appropriate isolating switching means interrupted by at least one

the counting pulses can be controlled during the call

In known circuit arrangements with time counting for long distance calls and simple counting at the end for local calls, unauthorized long-distance calls are disconnected depending on the first incoming counting pulse during the long-distance call. That with such systems an additional Evaluation of selected key figures as part of the blocking evaluation for the release or blocking Certain long-distance calls can be made using shared drives, of course. But will in principle in the case of such established telephone exchanges, the location count at the end of the call When local time counting is changed, considerable problems arise during the changeover.

The object of the present invention is to provide a simple way of eliminating local and remote time counts between local and long-distance calls in such a way that for certain groups of participants Long-distance calls can generally be prevented.

This is achieved in that in the circuit controlling the isolating switching means one of the Counting pulses incremental decade counter is switched in such a way that only with certain counter settings a signal that is effective for switching on these isolating switching means and / or connecting means is emitted will.

In this way, with a simple and integrable, therefore cheap device both an immediate as well as an indirect remote lock can be achieved. Due to the immediate remote blocking effecting isolating switch means, the established remote connection is disconnected. Through the indirect The connection switching means effecting remote blocking can cause a signal to be sent to the subscriber. One Such a simple arrangement can easily be combined with other existing ones Follow-up devices are used that carry out individual key figure evaluations in a known manner, to enable or disable certain connections for all or certain participants. Through the The simplicity of the arrangement and its integrability is low and also the effort per transfer of office independent of the system configuration of a private branch exchange.

According to a further embodiment of the invention, the connection means are used to connect a Audio signal or an announcement.

In this way, subscribers can be informed of the authorization of the remote connection. This signaling or announcement can also precede an imminent separation. The announcement can also be repeated with different increments of the counter.

Exemplary embodiments of the invention are described with reference to the drawings. In particular, they are also terms used above explained.

As is known, the counting pulses arriving from the public office in a private branch exchange are recorded in an additional transmission ZLJe in FIG remotely authorized participants are assigned. Since not all authorized participants are allowed to make long-distance calls, but local calls are allowed, it is known to

to be provided. The easiest way to do this was to use the different types of counting was assumed for local and long-distance calls. The first counting pulse of a long-distance call came along to control disconnecting devices, because for local calls, counting was previously at the end of the Conversation provided. Local calls only had a flat charge per call, regardless of the type Call duration. The counting of long-distance calls was carried out with the help of counting pulses during the Conversation.

But if the counting of the local fees is now also made time-dependent and is therefore carried out for this Local calls also include a count during the conversation, so the first can be done during the conversation Incoming counting pulses can no longer be used to identify and disconnect a long-distance call.

This type of monitoring of long-distance calls has become necessary in particular because of the possible manipulation when using shared drives. As is known, shared drives allow certain remote connections to be released and / or blocked on the basis of a comparison of the selected codes with codes stored in some way, if the subscribers are only authorized to a limited extent. Such follow-up drives can, however, be outwitted, i.e. bypassed, by the dialing participants, for example, by giving faster impulses or additional impulses. Such manipulations made it possible to occupy the yo first electoral level in public office before the follow-up drive could decide whether to enable or disable it.

But it is just as possible with these remote locks, in private branch exchanges without shared drives a general one To introduce remote blocking for self-dialing participants. In this case you can only make long-distance calls be conducted through the agency of the civil servant. These calls are then counted with a Counter at the attendant console.

From the foregoing it can be seen that the time is now counted during local and long-distance calls should be introduced. Accordingly, local and remote time counting as well as local and Remote time counts spoken. The charges for local and long-distance calls differ like the charges for different telephone zones, due to the different speed of the Counting pulse sequences and / or the counting pulse lengths. The faster a counting pulse sequence, the more pulses arrive at the billing meter within a certain call period and are all the more expensive also the conversation. From the foregoing it can be seen that both the counting pulses and the Count pauses for local calls and for different long distance zones of different Are duration. The following explains how this fact is used to transfer local calls from to distinguish between long-distance calls.

From FIG. 1 shows that the operated by the count from public office Contact Izrder additional transmission \ zr suppressive debounce EP are applied to a decade counter DZ žije an eventual separation of this contact. The decade counter DZ is incremented step by step by the counting pulses. With each forwarding, a signal is output at the next output of the respective outputs, for example 1 to 4. If the decade counter DZ has reached its end position, or if the connection is triggered, the decade counter is reset via a reset input Rü. In the present example it is assumed that the transistor T can be switched through via the output 3 when a signal is switched on at this output. The isolating relay Tr is then switched on via this transistor T and the connection established is triggered. A timer can also be connected in parallel to the decade counter, which can differentiate the local time counting pulses from the remote time counting pulses and which then interrupts the further application of pulses to the decade counter DZ in the case of local time counting pulses.

From Fig. 2 it can be seen that instead of a disconnecting means, a connecting means AN for connecting an audible signal to the connection path to the calling subscriber station can also be connected via the decade counter DZ. This sign can be an existing command as well as an announcement. The activation of the connection means AN can be limited in time to the charging time of the capacitor with a capacitor in the base circuit of the transistor 7Ί. If, on the other hand, no time limit is provided, the decade counter DZ is incremented when the next counting pulse arrives, thereby automatically interrupting the switch-on circuit for the connection means AN , thus preventing the further transmission of an audible signal. The signal can also be repeated in that, as is arranged, the connection means AN can be activated several times via several decade counter steps and a corresponding routable wiring.

3 it is shown that, instead of a connection means, a visual signaling can also be controlled directly at the subscriber when the decade counter DZ is set to specific steps. When using an optical signal, the subscriber can also count the number of incoming charge pulses if, for example, the lamp is switched on every two steps.

4 shows how the switch-on time of a switch-on means, e.g. B. Relay ON can be limited. Here, too, as well as applied in Figure 2 by contact of the Anschalterelais in the signs of the winding associated with the transmission of office transformer with a verbal command or an announcement. The monostable multivibrator is brought into the working position via an output of the decade counter DZ when the counter reading is appropriate for a period of time that is determined by a corresponding timer. This timing element can consist of a capacitor resistor arrangement with a certain time constant. The time constant can be changed by regulating the resistance value. Here, too, multiple activation of the connection relay AN for the purpose of transmitting an announcement is possible.

For this purpose 2 sheets of drawings

Claims (8)

Patent claims: 1. Circuit arrangement for dialing control in telephone systems with local and remote time counting. in particular for private branch exchanges connected to such systems, in which all or certain subscriber groups are generally excluded from participating in long-distance connections and the attempted remote connections of such subscribers are interrupted by appropriate disconnecting devices, which can be controlled by at least one of the counting pulses during the call, characterized in that, that a decade counter (DZ ), which can be incremented by the counting pulses (\ zr), is connected in the circuit controlling the isolating switch means (Tr) in such a way that a signal that is effective for switching on this isolating switch means (Try) is only emitted with certain counter settings (e.g. step 3). 2. Circuit arrangement according to claim 1, characterized in that the decade counter (DZ) is preceded by a debouncing circuit (EP) in order to prevent bouncing effects of the contact (\ zr) transmitting the counting pulse. 3. Circuit arrangement according to claim 1, characterized in that instead of the isolating switching means (Tr) switching means (AN) are provided for switching on an audible signal or an announcement. 4. A circuit arrangement according to claim 3, characterized in that the switching on of the switching means (AN) which switches on an audible signal is carried out recently limited by a capacitor connected in series with a transistor (Ti) which controls the switching means. 5. Circuit arrangement according to claim 3, characterized in that the switching on of the switching means controlling an audible signal or announcement is terminated by a subsequent counting pulse as a result of the further switching of the decade counter (DZ). 6. Circuit arrangement according to claim 1, characterized in that a repetition of the audio signals or the announcement circuit takes place by appropriate sound at the outputs of the decade counter (DZ) . 7. Circuit arrangement according to claim 1, characterized in that optical signaling (L) for the subscriber is controlled via the outputs of the decade counter (DZ). 8. Circuit arrangement according to claim 3, characterized in that the time limit of the Connection of a transmitted signal from a monostable timing element fMÄ ^ takes place.