DE1537906B2 - Circuit arrangement for the processing of temporary switching measures of a subscriber in telecommunications switching systems with time-division multiplex control, in which each connection between two subscribers is assigned a line of a central circulating store - Google Patents

Description

1 2

In telecommunication systems with time-division multiplexer control- the connection containing subscribers is assigned, at which every connection between two net is the temporary switching measure Participants each have carried out a line of a central revision, under the influence of this running memory is allocated, there is a need to change the temporary switching action Switching measures that a participant 5 tactile point potentials for a predetermined period of time If it does more during a connection, it prevents the same change in the scanning speed as possible to process with little effort. In far-point potential in subsequent sampling periods, private branch exchange systems can it z £ -B. occur, is evaluated again. By creating a die that a participant who connects via office temporary switching measure, z. B. the earth mit the public switching center holds; for the participant's io keystroke, characteristic Si implementation a query with another gnals for a defined minimum period of time Wants to connect subscribers of the private branch exchange. savings in the central control for the In order to switch over to an inquiry, it is in the telephone central circulating memory. The defining signal PBX systems common to the subscriber to be-is recognized with certainty by the scanner, since it nem terminal set an earth key available 15 during several sampling periods in the subscriber that a circuit is available for temporary actuation. By each switching over however, its connection on inquiry connection is individually assigned time element and prevents successive detections in the event of a renewed temporary loading making the restoration of the original of the identification signal for the temporary Trunk connection initiated. 20 switching action the central controller repeats

There are already circuit arrangements with time actuation.

multiplex control known (Auslegeschriften With particular advantage, every connection can do this 156 and 1190 062), in which temporary training is individually assigned timers through in-min switching measures of a participant, e.g. B. for the purpose of least two columns of the central memory angeord-initiation a consultation call, processed 25 nete memory elements are formed of which will. When submitting the query criterion (e.g. the memory elements of each line individually an an eleventh digit key) can be set with the during all memory pulse phase the subscriber connection via a Si element of each of the two columns periodically output multiplex line and the central control alternately on the part of the central control back-digit receiver allocated. This recognizes the 30 to be placed. Depending on when Query request and causes the central control within a reset period to set the tion to block the previous pulse phase and memory elements of a line that serve as a timing element to allocate a new one, with which the inquiring takes place, these memory elements remain for the duration Participant chooses and speaks. at least one and at most for the duration of the

With these known systems, it is difficult to effectively set the sum of all reset periods, This can occur when the subscriber can individually set a time inquiry button for each connection who cycle time is determined in comparison to the number plate range with a corresponding tolerance (e.g. 100ms) too short or too long the one within which certain processes are blocked presses. In the first case the criterion can be lost.

go, in the second case there is a risk that the 40 An exemplary embodiment of the invention is shown in the central control anew with each cycle. It shows
it is stimulated that further new pulse phases arise with it. 1 the connection circuit of a subscriber is laid or that the key position that is too long

press a second press of the button, with which the back F i g. 2 the principle of a central storage facility,

inquiring participant the original connection 45 F i g. 3 a, 3 b the block diagram for the processing

wishes to resume, no distinction between pressing an earth button,

will. In the case of the in FIG. 1 connection circuit shown

The invention has set itself the task, which is to the terminals a, b leading to the participant

Influence of the length of this temporary switching connecting line connected. A middle one

action to be eliminated and the criterion is only used for part of the circuit marked with fbA W

times to process. for evaluating the free and occupied status of the

About the processing of such temporary subscriber line. Another with ET-A W designated switching measures of a subscriber with the neter possible part of the circuit is used to enable evaluation of little effort, sees the switching grounding on the subscriber line,
processing arrangement according to the invention that the 55 The circuit for vacant and occupied evaluation by means of a scanner periodically interrogated scanning sits a scanning point M, which is periodically interrogated by a non-point of the connection circuit of each participant with the scanner shown. The one capacitor with parallel-connected resistor sampling point M is connected to the tap of a resistor, the state of charge of which is formed by a voltage divider R 4 and RS. The by a temporary switching measure of the part 60 resistor R 5 is connected to the operating voltage BS from taker (earth button) influenced transistor from +5 V. The resistor R 4 is pending and whose time constant is dimensioned so a diode D 5 is connected to the reference potential 0 V that the potential of the sampling point is also for a short period of non-conductive switching action for a multiple sampling when the circuit is idle. The operating voltage BS of + 5V is therefore located at the sampling point M over the minimum period of time for the resistor 65 .R 5 that lasts over the periods. Scanner is changed recognizably and that each line hangs the subscriber at the end of the connection of the central circulating memory contains a timing element, leads his listener off and thus closes a which after setting in the line, which a circuit over both wires a, b of the connecting line

device, then resistor R 1 is traversed by current. As a result of the voltage drop occurring across the resistor R 1, a transistor Π is switched to be conductive. Through the emitter-collector path of the transistor T1 , the supply voltage SP of -48 V is switched via resistor R 3 to diode D 5 so that it becomes conductive. A current now flows from the operating voltage BS via resistors R 5 and .R 4 of the voltage divider and the diode D 5 to the reference potential BP. This lowers the potential at sampling point M to practically 2.5 V. If the scanner, not shown, picks up this potential, then a discriminator connected to the scanner can recognize that the associated subscriber line is busy.

The parallel connection of a capacitor C 2 and a high-resistance resistor Rl is also connected to the sampling point M via a diode D 8. This parallel connection is via the emitter-collector ao gate path of a transistor T1 to reference potential BP, to which the wire b of the connecting line is also connected. The transistor T 2 is conductive as long as feed current flows over the subscriber line, so the subscriber is busy.

If the subscriber earths his connection line b, there is no current flow through the resistor R 9 because the reference potential BP is also earthed in the control center; this blocks the transit gate Γ2. The right end of the parallel connection of resistor R 7 and capacitor C 2 is connected via a resistor R 6 and a diode D 7 to the collector of the transistor Tl , which continues to flow through the α wire of the subscriber line due to the current flow maintained even during an earth button pressure Supply voltage SP of -48 V leads. In the circuit from reference point BP (0 V) via diodes D 6 and D 8, capacitor C 2, resistor R 6, diode D1, collector-emitter path of transistor T1 to supply voltage SP -48 V, capacitor C1 is charged . As a result of this charging process, the voltage of the sampling point M is lowered to 0 V and beyond that to a slightly negative voltage. The duration of this voltage drop is essentially determined by the capacitance of the capacitor C2 and the resistance value of the resistor R 6. By suitably dimensioning these components, the duration of the voltage drop can be measured at around 40 milliseconds, regardless of whether the subscriber presses his earth button for a second or longer depresses and blocks transistor Γ 2 for this period. During a time span of 40 milliseconds, the scanning point M is scanned several times by the scanner, not shown, so that the operating state "Earth key press" can be recognized with certainty.

A capacitor C1, the other assignment of which is connected to reference potential BP , is connected to the sampling point M. A diode D 6 connected in parallel with this capacitor C1 is used to suck up any negative voltage present at the sampling point M according to the reference potential BP. Even during the charging process of the capacitor C 2, the sampling point M can therefore only carry a negative voltage temporarily.

The in F i g. The central memory shown in FIG. 2 is designed as a toroidal core matrix with a maximum of 100 lines, corresponding to a hundred simultaneous connections. The information for identifying each connection is divided into eight columns, each of which contains several columns. The column RT-A takes on the address of the calling subscriber; the column GT-A the address of the called subscriber; the column Ber an identifier for the respective authorization; the column VA an indicator for the respective type of traffic; the column RK the address of the register used to set up the connection; the column SZ is used to receive special characters and the column Pr to identify the program item, ie the status of the connection establishment of the connection in question. The setting of the columns SZ and Pr is controlled by the program control PST of the central controller, and the setting of the columns RT-A to RK is controlled by an information input memory JEG . The control takes place via transfer gates UG, to which the outputs of a statistical memory SS are also connected, into which the contents of the individual rows are transmitted one after the other via read amplifiers LVS of the individual columns.

A read amplifier LZ and a write amplifier SZ are assigned to each memory line. The read clock lines LTL and the write clock lines STL of the individual memory lines are acted upon one after the other by a clock generator via a distributor (not shown). If a toroidal core is tilted into the rest position with the read command current, the connected read amplifier LVS is controlled via the read wire assigned to the relevant column and the flip-flop circuit of the static memory SS assigned to this column is controlled via this.

If a connection is established between an exchange transmission and a subscriber, the memory line assigned to this connection contains indicators in column VA, indicating whether it is an outgoing or incoming exchange connection, indicators in column RT-A or GT-A, depending on the situation whether a calling subscriber has occupied an outgoing line or whether the subscriber is called in an incoming connection; The address of the register used is also marked in column RK-A and program item 7, which is assigned to the speech state, in column Pr.

If the subscriber now temporarily actuates his earth button, a signal of about 0 V for about 40 milliseconds is sent to the assigned sampling point M. The sampler, not shown, emits a corresponding signal at the sampling time, which occupies a free register that is his Identification code to the register address memory of the information input JEG . In addition, the address of the subscriber is placed in the RT and GT positions of the information input JEG . When the address of the occupied register is transferred to the information input memory, its memory location RK-A deviates from 0. As soon as this deviation is determined via an OR stage Fl _n (Fig. 3a, 3b), the program step generator PSG is started in the program control PST and at the same time the flip-flop ET-FF is set in the central control. No test takes place during the subsequent cycle of the central memory (0.NT). At the beginning of the next circulation cycle (1.NT) is on a line NTl

Activation potential for an AND stage U3 _N , by means of which the register address in the memory location RK-A of the information input JEG is compared with the register addresses stored in individual lines of the central memory, which are successively transferred to the static memory 55. " i) This test must have a negative result, since a new register was occupied by pressing the earth button defi.

With the next storage cycle 2.NT there is a comparison of the address set in the storage locations RT-A and GT-A of the information input JEG with the addresses available in the columns RT-A and GT-A of the entire central memory via the static memory SS by means of two AND links U 2 ET and U 3 ET, which are activated via a line NT 2. There must be no trip indicator on the RK-AsI line.

Since the subscriber who had pressed the earth key was already connected to an exchange line, his address must be in one line either in column RT-A or in column GT-A . As soon as a match is found in the AND link V2-ET or the AND link C73- ET with the address present in the information input JEG , the OR link VI-ET, which is connected to the two AND links, introduces positive signal. The result is checked again with the help of a further AND link VA-ET that the line found in the central memory has the program point PP 7, which corresponds to the call status and the traffic type VA-Ag or VA-Ak is identified, that is, a Outgoing or incoming trunk transfer is busy.

If these matches are present, the AND link VA-ET emits a positive signal, which activates a further AND link JJS-ET. This AND operation has two blocking inputs, which block them if an identifier is stored in the storage location VA-ET or in storage location 5Z-0,2. If an identifier is stored in one of these memory locations, then the connection in question has already been switched to consultation and must not be switched again. However, if this blocking indicator is not present, the AND link U5-ET emits a signal by means of which the flip-flop ET-FF is reset and the traffic type identifier VA-ET and the special character SZ-0,2 in the corresponding memory locations of these Line can be saved.

Since the signal indicative of an earth key press is present at the output M of the subscriber circuit (FIG. 1) for about 40 milliseconds, the scanner derives corresponding signals several times in succession during the periodic scans, which can be requested again from the central controller. To prevent multiple evaluations of such signals, each line of the central memory, which is assigned to an exchange connection in which the earth button was pressed, is blocked for a period of at least 0.2 seconds by the special character 5Z-0.2 as soon as the traffic type identifier VA-ET is saved or deleted in this line.

The special characters 5Z-0,2 are stored in such a way that the magnetic core is placed in at least two columns of the ten columns in the column SZ in the relevant row. For example in columns 46 and 47. On the part of the central controller, all cores of columns 46 are alternately erased during one cycle of the central memory or all cores of column 47 during one cycle of the central memory. The one on the line in question right now

Cores set in columns 46 and 47 are therefore deleted after 0.2 seconds at the earliest and 0.4 seconds at the latest. As long as the cores are set, they give a blocking signal to a blocking input of the AND stage US-ET when interrogated via the static memory SS.

At the end of the memory cycle 2.NT it is certain that the subscriber's actuation of the earth key was authorized and that an inquiry connection is being set up. During the next

ao memory cycle 3.NT a free further row of the memory is to be occupied because the flip-flop ET-FF has been reset. A line in the program item PPO is searched for via an AND link U 6-ET . This line is followed by the .. 'output signal of the AND link TJ6-N after - * ♦ the program item PP l' _s Due to the coincidence of the new program point PP l ' _s with the old program point PPO _PS in an AND operation UT _n , the register code address, the subscriber address and the identifier VA-ET as well as the special character 5Z-0,2 are saved in the new line. Furthermore, the occupied-new flip-flop JSiV- FF is set, which blocks the AND link U6-N so that another free line can no longer be occupied.

During the following storage cycle 4.NT , the register code address, the address of the calling subscriber and the program points PP 1 are checked for correct storage. If the result is positive, an AND link US- _N emits a signal which stops the program step generator. The query structure is now complete. The subscriber can now submit the dialing information for establishing a connection to a desired other subscriber in the usual way. The address of the called subscriber is stored in the new line of the central memory occupied for the inquiry connection, and the call connection is then switched through in the corresponding program point.

If the subscriber presses the earth key a second time to cancel the inquiry connection, a register is occupied again and the central control is started after the addresses have been transferred to the memory locations RK-A, RT-A and GT-A of the information input JEG. Furthermore, the flip-flop ET-FF is set again. In the second memory cycle 1.NT , the address of the newly assigned register is compared with the register addresses stored in the individual lines of the memory. This test must have a negative result, as a register was newly assigned by pressing the earth key. During the following memory cycle 2.NT , the address of the subscriber who hit the earth button, which is set in the memory locations RT-A and GT-A of the information input JEG , is compared with the address columns RT and GT des

entire memory via the static memory SS with the aid of the AND links U2-ET and E / 3- ET, which were activated via the NT 2 line. As soon as coincidence is determined in one case, the OR link V1-ET emits a positive signal. In the AND link U 4 ET it is then checked again whether the line found in the central memory has the identifier wA-Ag or VA-Ak and the program point PP 7 -If this is the case and the office line is found, then the AND- Link JJA-ET from a positive signal, which prepares the AND link US-ET. If this AND link can add a signal to the traffic type identification VA-ET , which is set when the connection is in the inquiry state, and if there is no blocking signal from the special character SZ-0,2 , then it emits a positive signal, which stores the special character SZ-0,2 and causes that the traffic type identifier VA-ET can be deleted.

The line occupied by the inquiry connection is found, starting from the AND link U2 _ET , via a further AND link (not shown), since the inquiring subscriber can only stand as a calling subscriber in the column RT of the inquiry line. The query line must not have the traffic type indicator VA-Ag or VA-Ak . It must not be blocked by the special sign SZ-0,2 , but the traffic type sign, marked VA-ET, must be present.

These processes achieve 2.2VT in the storage cycle:

a) since the Verkehrsartkennzeichen VA-ET is stored within both lines, it is in the latched in the information input JEG indicator VA-ET to a command to reduce back connection;

b) the exchange line was found via the AND link U4-ET , and the query identifier VA-ET was deleted in this line, thus creating the possibility of reactivating the speech path of the original exchange connection;

c) the query line was found via an AND link, and for this line now activated a release program.

If, on the other hand, a subscriber who initiated an inquiry call during an exchange connection wishes to transfer it, then the address of the called subscriber, to whom the connection is to be transferred, stored in column GT-A of the line used for the inquiry connection, must be transferred to a special memory be taken over. This is initiated by hanging up the inquiring subscriber in the inquiry state. This immediately deletes the query line. The exchange line must be found in a subsequent storage cycle, and the address of the subscriber called in the inquiry connection in the special memory must be stored there in place of the previously written address of the extension subscriber and the inquiry identifier VA-ET must be deleted. The central control can then be shut down.

Claims (2)

Patent claims: 1. Circuit arrangement for the processing of temporary switching measures of a subscriber in telecommunications switching systems with time-division multiplex control, in which each connection between two subscribers is assigned a line of a central circulating memory, characterized in that the sampling point (M) of the connection circuit (Fig . 1) Each participant is connected to a capacitor (C 2) with a resistor (R 7) connected in parallel, the state of charge of which is dependent on a transistor (Γ2) influenced by a temporary switching action by the participant (earth button) and the time constant of which is such that the potential of the sampling point (M) is changed noticeably for the sampler even with a brief switching measure for a minimum period of time lasting several sampling periods and that each line of the central circulating memory contains a timing element (SZ) which, after setting in the line, which one it is assigned to the subscriber-containing connection who carried out the temporary switching measure, under the influence of the change in the sampling point potential caused by this switching measure for a predetermined period of time, prevents the same change in the sampling point potential from being reevaluated in subsequent sampling periods. 2. Circuit arrangement according to claim 1, characterized in that the timing elements of all rows of the central circulating memory are formed by storage means of at least two columns (SP 46, SP 47), which can be placed in each row as required, while the storage means of the two columns ( SP 46, SP 47) periodically alternately for the duration of one cycle of the central memory on the part of a central controller (PST) are reset, so that in each line of the circular memory the storage means (SZ) serving as a timing element at least for the duration of one and at most for the Duration of the sum of all reset periods can be effective. For this purpose 2 sheets of drawings 009 519/90