DE721956C - Circuit arrangement for telex extension systems with dialer operation - Google Patents

Description

Circuit arrangement for telex extension systems with dialer operation From telex extensions there must be the possibility of further house subscribers (Extension subscriber) as well as reach subscribers of the public network to be able to. It is therefore necessary that; by the extension subscriber the choice of a prefix first the direction in which he intends to write, is determined. This is done by the extension subscriber making the selection between two codes, one of which connects to other extension subscribers (House line) ensures, while the other, the so-called exchange code, the connection of the extension subscriber to the public office.

If the extension teletype subscriber presses his call button, so you must first wait for the official signal from the extension center before you the election can begin. If the extension subscriber dials according to the received The exchange code from the branch exchange is now the exchange code to a subscriber To reach the public network, so long after dialing the outside line code wait until the selection in the public office becomes a free group voter has found. If the extension subscriber dials the outside line code immediately further, the case may arise that a free group voter is not yet available Is available and the choice is mutilated or the calling party a wrong one Connection received.

Since the second, returned from the public office to the participant Official sign at the participant can not be evaluated without complications the subscriber would be required, gives the present Invention means on how by simple switching measures and how by suitable Selection of official or Extension code after dialing the prefix can be the main choice immediately without the inclusion of a waiting period lcann.

To avoid waiting between choosing the prefix and the main choice, according to the invention, switching means are provided which, after the start, but preparing the exchange line before the dialing of the outside line code is completed occupy, but only after you have completed dialing the outside line code of the calling N extension subscriber on d'e: exchange line- 2 #. allow so that at the end of the dialing of the prefix with security for the calling subscriber a free group voter in public office is available and unrelated on .the choice of the prefix the main choice can be made.

According to the further invention, the outside line code is in size chosen so that the between the preparatory assignment of the trunk and the final connection to the exchange line is the same or greater than the maximum duration of the area code in public office.

According to the further invention, the extension code is related on the outside line code selected in size so that when dialing the extension code the trunk remains unoccupied.

It is advisable to use the o as the exchange code and the extension number the i used. According to the further invention, when dialing the outside line code, the Preparing the exchange line after sending the second pulse of the exchange code proven.

There is already a circuit arrangement for telephone systems with Voting company became known, in which different by choosing a prefix Traffic routes (e.g. extension line and exchange line) can be occupied. the known circuit arrangement is made so that at a certain pulse train a mixed selector is occupied, which mediates the connection to the public office. This z. B. occupied by the code numbers i to 6 extension lines, while the remaining higher-order codes provide instructions. For the purpose of avoiding simultaneous seizure of an exchange line when dialing one The extension dialer is provided here for the extension subscriber, the trunk line assign preparatory evidence. Then when it is decided that an exchange line will be seized the final connection takes place.

If the participant chooses e.g. B. the code S, which is an outside line code , the mixer selector is only occupied when the rotary selector has passed the 6th step deletes. At the same time there is a final connection to the exchange line, which was previously occupied by the mixer selector only in preparation.

The known circuit arrangement has the purpose of an unnecessary To prevent the trunk line being seized when dialing extension subscribers.

On the contrary, in the present invention, care should be taken be borne that immediately after the end of the choice of the prefix the Main choice can be made as a dial tone from the public office to the telex extension subscriber cannot be retransmitted, as is easily done in telephone technology is possible through eavesdropping.

An example embodiment of the invention is based on a Figure will be explained in more detail. All insignificant parts of the exemplary circuit arrangement are omitted in order not to impair the clarity of the circuit arrangement.

If an extension teletypewriter operates his call button and if he receives the dial tone from the extension office, he has the option of choosing the prefix, either the number i or the number o, two different traffic routes to be able to prove. If the prefix i is selected, it is reached the calling subscriber when dialing the extensions (house subscribers) Dialing the outside line code o on the other hand, the external line and when dialing (main dialing) the desired participant in the public network.

Assume that the calling extension subscriber is a subscriber of the public network wants to call.

If the extension subscriber dials the outside line code o after pressing the call button and after receiving a dial tone from the exchange, the c-arm of the line selector LIl 'first passes over the contact i of the selector. However, since the H relay connected to your contact i has a delayed response, simply swiping over contact i has no effect whatsoever. When contact 2 is subsequently passed over, the A relay responds immediately via the closed h2 contact of the H relay. The ai contact closes and the holding winding of the A relay is excited via -, closed contact ci, closed rzi contact, holding winding A II, -. By closing the a2 contact -v ird + to the one leading to the public office a-line placed over -f-, closed a2-contact, closed c2-contact and the trunk line pre-assigned. As a result of its holding excitation, the A relay remains activated even if the c-arm of the line selector LW is moved on from contact z to the next contacts. If the c-arm of the line selector comes on the io. Contact to rest, the C relay is excited via test wire c. Contact ci opens and the A relay drops out. When the C relay responds, the cz contact is opened and + is removed from the a wire. Since the a and b arms of the line selector, the io. Step, the subscriber is switched through to the remote exchange. During the time in which the arms a, b, c of the line selector pass over the contacts: 2 to io, the pre-selection in the public office had enough time to select a free group voter due to the pre-assignment carried out when the contact z was passed over. Right now as the arms of the line voter hit the io. Step, the calling extension participant in the public office has a free group selector available so that the main dialing for dialing the desired participant can take place immediately after the prefix has been terminated.

It is now assumed that the calling telex extension subscriber wishes to reach another extension subscriber (house subscriber). For this purpose, the calling extension subscriber dials the code number i after pressing the call button and after receiving the dial tone from the extension office. When you dial this number, the c-arm of the line selector LW remains on: the i. Contact is made, and after the delay time has elapsed, the H-relay responds and is held by its holding winding via the circuit +, closed head contact k of the line selector, closed ls i contact, holding winding H II, -. When the H-relay responds, the 1a 2-contact is opened, so that when the main dialing following the prefix is passed over the second contact of the line selector, the A-relay can no longer be activated and the trunk line cannot be pre-assigned. By dialing the digits a to 8, the calling subscriber reaches the desired extension subscribers 3 to 9.

Claims (1)

PATENT CLAIMS: i. Circuit arrangement for telex extension systems with dialer operation, in which different traffic routes (e.g. extension line and exchange line) can be occupied by dialing a prefix, characterized in that switching means (A) are provided which start after the dialing of the exchange code has been completed but before completion Occupy the exchange line in preparation, but only allow the calling extension subscriber to pass through to the exchange line after dialing the exchange code number, so that when the prefix number is dialed, a free group selector in the public office is definitely available for the calling subscriber and is immediately available the choice of the prefix the main choice can be made. z. Circuit arrangement according to Claim i, characterized in that the size of the exchange code is chosen so that the time between the preparatory seizure of the exchange line and the final connection to the exchange line is equal to or greater than the maximum duration of the dialing code in the public exchange. 3. Circuit arrangement according to claim i and z, characterized in that the extension code is selected in relation to the outside line code in size so that when the extension code is selected, the exchange line remains unoccupied. 4. Circuit arrangement according to claims i to 3, characterized in that the o is used as the exchange code. 5. Circuit arrangement according to Claims i to 3, characterized in that the i is used as the extension code number. 6. Circuit arrangement according to claim 5, characterized in that when the exchange code is selected, the exchange line is occupied in preparation after the second pulse of the exchange code has been sent. 7. Circuit arrangement according to Claim 3 to 5, characterized in that switching means (1-I) are provided which, after the extension code number has been selected, prevent even a preparatory occupation of the exchange line during the main dialing. B. Circuit arrangement according to claim 7, characterized in that delayed-on relays are used as switching means (H).