DE2459555C2 - Method for controlling a time division multiplex switching system controlled by a stored program - Google Patents

Description

In known spelcher program-controlled tent multiplex telecommunications in particular Telephone switching systems is a relatively complex and complex one complex control device together with extensive large storage facilities are required. This is the

Use was restricted to large systems.

A well-known system (US-PS 32 68 669), which operates a private branch exchange for a variety of private branch exchanges allows, this problem has partially overcome in that the control device and the large storage facility is located in a central location, for example in a public exchange and remote switching units as well as the inquiry stations of the switching systems on Seat of each private branch exchange are provided.

The known system is economically advantageous under certain conditions, but it is little suitable if there are only a few and small private branch exchanges. In addition to the improved operating features Time-division multiplex switching systems that are controlled by memory programs have particular advantages for private branch exchanges because of their relatively small space requirements, because for smaller private branch exchanges the economic success of the system depends to a certain extent on its space requirements.

The circuit breakers of every tent multiplex switching system need each participant of a connection only during the occurrence of the tent position associated with the connection with the time division multiplexing connect to. Each circuit breaker is normally open, but can be under Response to f! N control signal from the system control are closed to the participants involved in a connection during the assigned time slot to be connected to the manifold.

In order to be able to give the necessary control signals to the line switch, the system must provide information save, which indicate the respective assignment between the tent locations and the switches. aside from that Every facility must have facilities that use this information to switch every switch operated during the assigned tent position. at known plants are presented of two different types. Tax systems to carry out the above functions described.

The first of these two systems could be called a distributed storage system. The second The system is called the central spelcher system. In which Distributed storage system becomes the identity of the Tent position to which a circuit breaker is assigned, In Stored memory elements specially assigned to each switch. The storage element is often a shift register, that has a number of positions equal to the total number of tent plies. The position . which corresponds to the tent location. In the the line switch is to be closed contains a 1. The shift register is shifted by one position per tent layer and then read out. Whenever a bit with a 1 is read from a register, will the line switch assigned to the register is closed for the duration of the tent location. One downside to this Distributed Storage Systems Is that proportionate large number of circuits for performing the control function in writing information In the shift registers for the purpose of assigning the line switches to the tent locations and when deleting Information in the shift registers for the purpose of canceling the assignment at the end of the call and at the Control of the incremental advancement of the shift register are required.

The central storage system has at least one Word required for each time slot. Each word must have a large number of fields. For example, if

in a conference call, three line switches connected to the bus line during a tent location must be, the memory word for this tent location must have three fields to each of the three To be able to identify circuit breakers. One disadvantage of the central storage system is the problem of scratching and reading out information in or from the selected word as well as the problem of Decoding of the line switch information after reading it from the memory.

Although although both the system with distributed storage as well as the central storage system are satisfactory work, their effort and complexity are so great that the realization of the Advantages of time division multiplexing not with kielis ner systems, for example those with 20 to 100 subscriber lines, came into play.

It is also the case with tent multiplex switching systems required that the tones required for each call connection only during the respective Connection assigned time agc to the bus given so that a tone required for a connection does not interfere with other connections.

In known tent multiplex systems, the supply of operating tones is taken over by facilities, which store or monitor the status of each connection, determine based on this monitoring, when a tone is required for each connection, and then the actuation of one of the sound sources assigned Line switch to control the sound source during the correct tent location with the tent multiplex collection connect to. Numerous devices for performing these functions are known in the art Catfish have been used. However, this requires a relatively large number of circuits. It is already a memory with a word memory location for each time slot, with each word having a plurality of fields. One this field is assigned to the tone control function, with the type of tone made during the occurrence is to be fed to a tent layer, by means of which bits stored in the sound field are indicated.

From DE-OS 1913 990 is a method for Acquisition and delivery of data signals, in particular switching identification in a PCM switching center of a PCM telecommunications network known in which in a certain tent location successive Within the framework of a superframe, data signals are transmitted, each of which is a different tent location or also a Collective of tent locations oet meet. The data signals are also used in the exchanges Handling of operations is used, but the known method is essentially one Transmission problem. directed and does not deal with the control of a switching system.

The invention has set itself the task of a To make available a method for the control of tent multiplex switching systems, the one simple and economical construction of the control device, so that even smaller systems and «> In particular, implement smaller private branch exchanges at a reasonable cost.

The solution to the problem is given in claim 1. Further training that is also based on a spelcher program-controlled Time-multiplex switching system is aimed at carrying out the procedure, are the subject of the subclaims.

In addition to using a highly organized.

especially for switching in private branch exchanges trained instruction set, the control unit is also less complicated because it is the processing of the call using data transfer operations between memories and perlpheres Elements, as well as by using a single comparator to perform all logical operations and the decision-making fictions required in the annex enables. The control unit does not require an arithmetic unit or special purpose register.

A system according to the invention contains a number of memories which are addressed with the frame or connection number of the connection being served. Call processing only involves exchanging the contents of the addressed memory between different components of the system. The comparator compares the content of various program words with information that has been read from the memory or with information that comes from peripheral components. Depending on the results of each such comparison, atf processor causes the operation of a peripheral unit, performs the work function in connection with another word in memory, or effects the work function in connection with the next word in memory.

The facility is both frame- and tent-orientated. Every conversation connection becomes a special one Tent position assigned within a frame and the tent multiplex switch connected to a connection Participants involved are closed during each occurrence of the time slot assigned to them. the Frames are arranged in constantly recurring groups and also within a group Numbered so that they are aligned with the time slot numbers. The processing of a call connection occurs during each occurrence of the frame number that is the same as the number of the connection assigned tent location is. The processing of a call that is assigned to tent location 1, takes place during each occurrence of frame 1. In this way, the call processing is In In the form of a single unit, apart from the fact that it is subdivided in time, so that the plant can handle a large number of call connections at the same time.

The following is a system with 64 tent layers and 64 frames, denoted by 0 to 63, are described. Each tent layer has a duration of one microsecond. A frame comprises a total of 65 tent layers and accordingly has a duration of 65 microseconds.

The system described carries out the call processing by stepping through the frames step by step, cyclically and under control of a frame counter and a portion of the processing is performed during each frame time. During each occurrence of the frame 1, the system carries out all the conversations that go to this point of interest is required for a conversation, the the tent location 1 is assigned 1st. When a free frame is encountered, the frame time is used to scan free connections for the presence of a Operating requirement. The same time is consumed each time a frame occurs, regardless from the traffic noise and regardless of the particular section of the conversation being processed. The attachment has a tent ply that is a conversation state word for each tent position and a tent position counter is passed every microsecond

is switched. Each state word gives the instantaneous State of the call connection assigned to the time slot and the corresponding frame again. Each status word also gives the address of the first word of a subroutine assigned to the status word. At the beginning of each occurrence of a frame is its status word from the time stamp read to perform a number of functions, one of which is the Make the program go to the address of the specified subroutine. This will make the plant brought under control of the subroutine so that they do the necessary for this section of the conversation Arbelt can perform.

The call processing takes place with the help of a large number of distributed special purpose memories using a single large ospelcher. In known large storage arrangements, the same Part of the memory can be used several times to store different types of information, and the The content of a certain memory word is only made more complex arithmetic and logical Operations read out. This includes determining the memory address for the required word and the Generation of a read command using the determined address information.

In the case of the present system, this becomes complicated Procedure not used and instead each storage unit either by the connection number (subscriber number) or the frame number of the M call connection served is addressed. A memory stores the frame number information and has a word position for each frame. The other type of storage stores the port number information and has a word location for each port. The frame M memories store such things as the state of the call connection, call information and a frame connection linkage table which indicates which connections are currently in each frame assigned. The port memories store information such as conversion information, requirement class information, call transfer information, Subscriber unit and connection free election group information, Busy-free information, etc.

A frame address counter generates the frame numbers one after the other. If a frame number is generated, it is given during your frame tent on a collecting line to the associated with the frame Process part of the conversation. The memory containing the frame port linkage table is content-dependent with the frame number addressed in order to determine the connection (s) involved in the call connection. The won Port number is then again put on a bus to display the corresponding word In to gain a connection memory or to control a peripheral unit.

The distributed memories are peripheral logic elements assigned to the tent multiplex coupling * o control the field and / or obtain information from it. The peripheral logic elements are connected to the Port number information addressed. To the peripheral elements that are controlled in this way, include outgoing registers, a delivery switch «state selector, a connection interval pulse control device and a ringing current controller.

The connection address and frame number information

matlon never enters the processor. The processor has no general purpose data registers. It works directly with the data from the various memories be obtained if they are with either the port number or frame number Informatlon addressed.

The only logical operation that the processor does performs is a comparison operation. The üorlgen Call processing functions become more appropriate by executing them outside of the processor Data transfer commands carried out, for example, a port number from a word in a Transferring memory to a peripheral register. Since each memory only has one type of data or information contains. A request for this type of data identifies the memory. The port or frame number gives the special word of the identified memory whose content is to be read out. Accordingly siciii every Wsr! dci program memory a command! at a high level that acts directly on the system, rather than a multitude of internal accounting operations is required. No complicated chain of data manipulations is required, to gain access to a single bit for which a decision is to be made.

The use of a high level instruction set and the automatic advancement of a memory if a frame occurs, it ensures that every call is processed. As a result, there is no need for a large and complicated program which contains a task distribution section. The complexity of the processor and the program is significantly reduced as in a typical large memory controlled Annex the higher-level program represents an essential part of the overall program.

One advantage of the present invention is that Creation of a tent multiplex switching system in which each connection corresponds to a particular time slot in a recurring group of tent locations as well as a special framework in a repeating one Group of frames is assigned. The line switches for the call connection are thereby used the assigned time slot closed and the information processing for the call takes place during the assigned frame tent.

The system has a tent layer memory that contains a status word for each frame and each tent layer each word both the current state of the frame associated with Call connection and the address of a subroutine represents to which the program for operating the respective section of the conversation is to pass.

In addition, a large number of distributed memories are provided that contain either the frame number information or the port number information. The output signals of these memories directly control peripheral components of the system in order to carry out the necessary work functions. This type of addressing avoids the calculation of memory addresses, which is the case with systems with large spelchem is required as well as the need to be complicated perform logical operations on data obtained by reading large memories have been. Bc! Systems with large storage systems must the memory output signals put into an arithmetic unit of the processor and complicated logic Operations performed to the as

determine next required work function.

In addition, there is a content-dependently addressable memory that defines the relationship between the frames and connectors. Any connection has a special word position in a memory. s When a frame is assigned to a call and a port number is determined, so will the tower number In the memory word position for the Registered connection. During each subsequent Occurrence of the frame becomes a content dependent Address search performed for this memory, where the frame number is the input signal 1st. The memory then outputs the port number that goes directly to the Implementation of further work processes is used, for example to determine the monitoring state a line, etc. The connection number information also causes other functions to be carried out, which include: a) registered mail

ZUSäizricher ίήίϋίίϊίαίΐϋπέΓΐ in another! Nhsitssb-

pending addressable memory, so that the Leltungsschalter are closed during the tent location assigned to the connection; b) Supply of information on circuits that cause the calling process to take place at the correct tent point; c) feeding of information on circuits for the purpose of controlling a free choice; d) Determination of the service class a call connection; e) Supplying information to circuits that indicate the occupied or idle state a line in a previous scan then determine if the system is valid Searches for requirements.

Finally, a tone generator is provided which is controlled directly by the conversation status words read from the tent location memory. The receipt of a status word, which is a call connection in the call state, dial state or busy tone state zügscrdr.st, causes the generator to give the respective tones to the Zeltmulltplex collective collection. So if a time slot is in the dial tone state, the tone generator receives this status word from the * o tent position memory and sends the dial tone to the bus line for the duration of the time slot of one microsecond. In response, the generator sends callback tones and busy tones to the bus when receiving tent sites in the call state or busy tone state.

The invention is described below with reference to the drawings described. It shows

F1 g. 1 and 2 tent diagrams of a system that supports the 'Show the relationship between tent locations and frame; so

Flg. 3 shows the block diagram of a system according to the invention in a schematic representation;

F1 g. 4, 5 and 6 In the arrangement according to F1 g. 7th further details of a system according to the invention;

FI g. 8 details of the tent location logic circuit of FIG. 5;

F1 g. 9 is a diagram showing the relationship between the tent locations and frames as well as the input and output signals of the circuit according to FIG. represents;

F1 g. 10 a typical subroutine of the system; to

Flg. 11 and 12 the program according to Flg. 10 in Form of a flow chart;

Fig. 13 shows details of PAM memory 513; Fi g. 14 details of the PIP spelcher 601; Flg. 15 Details of the tone generator.

Flg. 1 and 2 show the relationship between the time slots and frames as well as ways in which the tent layers and frames are arranged to form repetitive groups.

The top cell in Flg. 1 gives the tent of microseconds where the vertical bars that represent each microsecond are recurring in cycles Groups of 64 (0 ... 63) microseconds are arranged. The microsecond streak furthest to the left Is marked with 63 and represents the last microsecond a group.

The tent layers are In F1 g. 1 arranged so that they the duration of each tent location and the relationship between the two specify between the tent layers Interval between microsecond 63 of a first group and microsecond 0 of the next group. The next time slot is denoted by 0 and extends from microsecond 0 to microsecond 1. The other tentiages in this group are from 1 to 63 and each have a duration of one microscopic examination.

The lower part of the wing. 1 shows a single group of frames labeled 0 through 63. Of the the first frame is labeled 0. It has a duration of 65 microseconds. It starts with that first occurrence of tent layer 0 and ends with the end of tent layer 0 for the next group. the other frames each have a duration of 65 microseconds and each include 65 time slots.

Flg. 2 also shows a variety of tent layers and frames, the duration of each tent layer and each Framework as well as the temporal relationship between the tenting and framework. The top cell in Fig. 2 represents a variety of groups of repetitive Tents with a length of one microsecond. The remaining cells in F1 g. 2 show a variety of Frames including the duration of each frame, the temporal relationship between the different ones Frame as well as the temporal relationship between the frame and the tent locations. For example, the second cell from the top frame 0. It has a duration of 65 microseconds and begins with the Beginning of the first appearance of tent layer 0 and ends with the end of the next appearance of tent layer 0. The frame 1 comprises the interval of 65 microseconds, which begins with the second occurrence of the tent layer 1 begins and ends with the end of the third occurrence of tent layer 1.

General description - FI g. 3

Flg.3 shows the system according to the invention in schematic Shape. The system essentially contains a processor 304, a large number of hardware memories, for example the memories 301, 305, 313 and 315, a tent layer frame control device 303 Line switch controller 316, a variety of line switches 311, and a variety of wire pairs 312, which lead from the subscriber circuits to the subscriber stations. In addition, the plant contains a large number of busbars, cores, registers 329, as well as the gate circuits that are used to exchange Information is required between the various components of the system.

The time slot frame control device 303 has a frame counter 303/4, a tent position counter 303ß and a comparator 303C. The output signals of the time slot and frame counter give the respective Tent position and frame condition of the system. The comparator 303C shows a correspondence with that

Stand of the frame payer and tent position payer and switches the frame payer upon detection of such Agreement one position further.

The SAM (slot address memory = time slot address memory) memory 301 contains a word position for each tent location, and the content of each such word indicates the current status of the call connection assigned to the tent location. If no connection is assigned to a tent site, your memory section contains an "empty" status word which indicates that the tent site is currently free. The tent position counter 3035 delivers a signal via its output wire 310 to the SAM spelcher 301 once every microsecond. The arrival of this status word at the processor 304 causes it to run to the program address represented by the status word. The processor supplies gate ^switching and other control signals to the various components of the system under the control of the program in order to exchange the information required for the call processing. _.

To represent the operational status of the plant, the to be explained in more detail later, it is assumed that the system from frame 1 to frame 2 advances and that frame 2 is currently in the Frel state and no call connection served. In this case there is an "empty" status word in the tent layer 2 of the SAM spelcher 301 is stored. Of the Tent position counter 303ß gives a 2 via its output line 310 to the left input of the SAM-Spelcher 301, which then reads the empty status word for tent layer 2 via its lower output and accesses J5 Line 317 there. This line travels to the jump address input of the processor, and the arrival of the The empty status word puts the processor under control of what is specified by the status word Subroutine.

When a frame and a time slot are determined in the free state, -He system for scanning is more free Connections on operating requirements upper. For the call connection just described, the Processes now signals but the line 307, which the PACMPort Address Counter = connection address counter) Counter 314 to advance one position. The position of this counter gives each a connection or a subscriber line circuit again, and the counter is used to determine Bedlenungsanforde- so used. When the counter 314 is incremented one position, its contents go to the port address buffer 309, which takes up the connection address, saves time-wise and then the Bus 320 to line switch controller 316 transmits. The arrival of this information causes the control unit to query the corresponding subscriber line to find out your current on-hook status ascertain. This information is transferred back to control unit 316 via line 322 but they then carry the line 321 to the Vergieichssammelleltung 308 there. The. Collective line 308 leads to processor 304, namely to its comparison input, whereby the processor is informed of the current monitoring status of the subscriber switch * s is communicated. If the connection is free (attached), the PAC counter 314 is again through, the processor forwarded via line 307.

the next connection is queried and information Regarding / in the monitored state, go to processor 304 via comparison collection line 308 returned. This process continues until the The processing time of 65 microseconds assigned to frame 2 has expired or, alternatively, a connection Has been found in the off-hook state is located.

An off-hook status can represent a valid operating request. However, it can also be a subscriber line concern the moment in the state of speech Is. It can also represent a brief line interruption. With the help of memory 305 and in particular the BlM- (BuSy-IdIe Memory = Occupation-Frel-SpelcherJ-section of this Memory is used to determine whether a pending condition has been detected of a connection represents a new requirement.

Which are currently in the connection address buffer The port number located in 309 is now via the line 320 to the left input of the memory 305 given and transmitted to the BIM Spelcherabschnlit with the help of gate control signals from the processor. That The arrival of the port number causes the memory to read out information that corresponds to the current Specify the busy / free status of the connection. This information is transmitted via lines 323 to the comparison collection line 308 and then to the processor 304 comparison aisle. If the BIM memory section indicates that the line is busy, it means that the line is busy At the moment is involved in a different connection in a different position. In this case it runs the sampling of the connections under control of the PAC counter 314 continues.

If in the other case that of the BIM Spelcher Incoming information indicate that the connection was free at the last scan, so can the current unhooked status of the connection represent a new operating request. But since he also a temporary condition, for example a Lightning strike cannot definitely be determined during this occurrence of the frame 2, whether the current suspension status of the connection represents a valid operating requirement. Around To be able to make such a determination becomes one Busy display In the word of the BIM spelcher section associated with the port currently being scanned. Suppose that this is port 8.

After writing a busy indication for connection 8 in the BIM memory, the processor gives Signals via line 302, and the empty status word in time slot 2 of the SAM memory 301 delete it and write a "hang-up test" status word in its place. One the frame 2 and the 2 representing time slot 2 appears in the talk time slot section for port 8 of PAM memory 313. The address information for the Port 8 is applied to the left input of memory from port address buffer 309. The 2 will from the frame address buffer 326, which stores the current frame number, to the upper input of the speaking time slot section 307 of the PAM spelcher 313. The frame number is the address buffer 326 from frame counter 303Λ over the line 306 has been supplied.

This concludes the entire work that has to be done for the

Call connection during this occurrence of the The comparator 303C provides the last one assigned to frame 2 dlecrosecond when both the frame and the tent position counter is in position 2. Then «rztugt the comparator 303C outputs signals that serve a number of control functions. This includes forwarding of the frame counter 303 by one position on the frame 3. The system then carries out work for the Frame 3 and then work for the subsequent frames according to the In the SAM spelcher written call status word associated with each time slot.

The system then returns to frame 2, and the attachment check status word, this is now Stored in the tent sheet section 2 of the SAM spelcher 301 1st, is sent via line 317 to the jump address input of processor 304 is applied. This enabled the system to come under the control of the installation test subprogram. The next time frame 1 occurs, frame number 2 is sent to Office tent location section 307 of PAM memory 313. This causes the memory to be content-dependent Search for the identity of the one or those connections to be carried out at the moment the frame 2 and the tent layer 2 are assigned. It is assumed that this is port 8 Is, and therefore the memory returns an 8 on line 325 after the content-dependent search has been carried out to the connection address buffer 309. From there, the 8 is via the line 302 to the line switch control unit 316 transferred. The arrival of this information causes the control unit 316, the instantaneous To determine the monitoring status of the connection, and information via the lines 321 and 308 transmitted back to the vararbelter 304 showing the monitoring status indicates. If the port is now on-hook, the processor assumes that the The previous unhooking status did not represent a valid operating request. He then deletes the busy display for port 8 in the BIM section of memory 305 as well as the mapping between the Connection 8 and the tent layer 2 in the office tent layer section 307 of the PAM-Spelcher 313.

On the other hand, if the port 8 is off-hook 1st, processor 304 determines that it is is a valid operating request and then goes to the work functions, which for Connection of the calling subscriber line to an outgoing register 329- are required. The first The function that is required at this point is to monitor the state of the tent sheet section 2 of the SAM-Spelcher 301 to be changed from "attachment test" to "register request". This is done under control one applied by the frame counter 303/1 via the line 306 to the right side of the SAM spelcher 301 2 and under control of to the top input of the memory via line 302 from processor 304 . supplied »register request w status word. 'These two pieces of information together write that new status word “register request” in time slot word 2 of SAM memory 301.

After the word "register request" has been written into the SAM spelcher, the system does not carry any further Work function at this occurrence of the frame 2. There will then be work for others Framework and time slots carried out. The next time frame 2 occurs, the status word »register request« read out from the SAM spelcher 301 and transferred to the processor 304, which then under Control of a subroutine is transferred which causes the system to send a free outgoing Register 329- to be selected.

The register is selected by increasing it a signal to the permanent address memory 315 which then contains the port number of a first register to the connection address buffer 309, ίο This connection number is the buffer on the Bus 320, causing controller 316 to set the first register busy-free 329- / 1 to be determined. If this register is free, will it is occupied for the call connection. If it is busy it becomes the port address of the next register by applying the connection address of the first register to the HAM (Huntlng Address Memory) section of memory 305 and by reading out the port number of the next register via line 325 into the port address buffer 309 derived. In this way, a large number of outgoing registers can be consecutively checked until a free register is found.

If a free outgoing register is determined, corresponding information is given to processor 304 via lines 321 and 308, which then does a write operation to the PAM spelcher 313 to assign the port number of the register to frame 2. This happens because the Port number of the register from port address buffer 309 via line 320 to the left of the PAM memory and the frame number 2 from the frame address buffer 326 to the upper input of the speaking time slot section 307 is applied. In addition, the additionally required Gating signals are supplied on line 307 to cause the memory to perform the desired write operation to undertake. At the same time, processor 304 changes the call status word for the frame , 2 in the SAM memory 301 from "Register request" In "Dial tone".

After the call connection is brought into the "dial tone" state, the calling subscriber hears the dial tone (dial tone) which is given by the TongenUor 328 on the multiplex collective line TDB . The input of the tone generator is connected to the bus line 317, which receives the call status for each call connection served by the system when the tent position counter switches the SAM memory 301 once every microsecond from tent position to time position. The tone generator 328 includes a plurality of sound sources and a decoder. The call status words applied to the tone generator as input signals cause it to send the required tones to the time division multiplex bus. At the point in time under consideration, the arrival of the "dial tone" status word causes the generator to generate a dial tone and give it to the time division multiplex bus every time the tent position 2 occurs, ω When the calling subscriber hears the dial tone, he dials the desired digits Subscriber station, and the register associated with the connection, receives these digits and stores them in the usual way. The call status word in SAM-Spelcher 301 is changed to "Dial" when the first dial pulse is detected. This causes the tone generator 328 to divert the Wäblton from the time division multiplex bus during time slot 2.

switch.

While dialing the desired number frame 2 occurs several times. During each such occurrence, the divine 304 becomes under Control of a "dialing" subroutine brought that test the signals on bus 308 to determine whether a dialing signal is received from the outgoing register 329 assigned to the connection. If no such signal has been received, the verifier 304 performs the remainder for this occurrence of the frame 2 remaining tent does not work out.

Eventually it will occur on a subsequent occurrence of frame 2 detected a dialing signal. then the content of the outgoing register 329 becomes the TAM (TaId Address Memory) -Spelcher 339th led, which converts the dialed number into the connection address and into the Port address buffer 309 is there. The port address the called subscriber line is then via the bus 320 to the line switch control unit 316 given, which checks the busy-free status of the called subscriber line. When the subscriber line is busy, a corresponding display is sent via lines 321 and 308 to processor 304 2 $ returned that the call status in the SAM spelcher 301 changes from »Dial« to »Busy«. This causes the tone generator 328 to generate the busy tone to give the time division multiplexing to inform the calling party that the called Subscriber busy 1st. In the other case, if the called subscriber line is free, your Port number assigned to tent location 2 by adding a 2 to the talk time slot section 307 of the PAM server 313 is written into the connection word for the called subscriber line. Simultaneously A 1 is now written into the M and P fields of the memory 313 for the same connection in order to indicate that this connection is the called connection.

After the called connection has been determined to be free, the status of the connection is stored in the SAM spelcher 301 changed to "Call". This causes a ringing tone to be sent to the calling party from the tone generator 328 is returned and a ringing stream is routed from controller 316 to the called terminal.

If the called subscriber answers, the call status in the SAM-Spelcher 301 is changed to "speaking", and the two subscribers are connected to each other whenever the tent layer 2 occurs. This is done under the control of the line switch control device 316, which causes the line switches for the calling and called connection to close each time the tent layer 2 occurs. The control unit 316 receives the time slot information via the line 310 from the tent position counter 3031 and uses this information to close the line switches of the connections assigned to a connection. The control unit 316 contains a content-dependently addressable memory analogous to the PAM memory 313, which stores information which indicates the current assignment of each ^w connection to a tent location. If a connection is to be assigned to a tent layer, for example if the calling connection is to be assigned to tent layer 2, the connection number is given via the position 320 and the dial number 2 via the line .MO in the security device 316. With the aid of suitable synchronization and gate control signals from the processor 304, the content dependent memory in the control device 316 assigns the tent layer 2 to the connection 8. Correspondingly, if the called connection is determined to be free, its connection number is sent via bus 320 to control unit 3IvS and written there into memory under control of time slot number 2 arriving from line 3! 0 from the tent position counter. With each subsequent occurrence of time slot 2, the arrival of the time slot number in control unit 316 causes its memory to carry out a content-dependent search for the purpose of determining all connections that are assigned to time slot 2. Each connection is assigned to one of the wires 330. During each tent position, an output voltage is given to each wire that is currently assigned to the time slot in order to operate its line switch. In this way, the line switches for the connection operated during time slot 2 are closed, so that a connection with the time division multiplex collecting system and thus with each other is established. The assignment of the Reglsteranusses to the Zeitiage 2 is deleted and its BIM word in the memory 305 marked as free when the call is answered by a 0 in the speaking time slot field for this connection in the PAM memory 313 is written.

After establishing the connection between the two subscriber stations, the system runs a content-dependent one Search PAM spelcher 313 on each subsequent occurrence of frame 2 to find the determine the current monitoring status of each connection associated with the connection. This is done by transferring frame number 2 from frame address buffer 326 via line 326 is passed to the upper input of the PAM memory 313, the port number of the calling and called Subscriber enters one after the other into the connection address buffer. Then he initiates the control unit 316 to check the status of the line associated with the port and the status information becomes returned to processor 304 via lines 321 and 308. The connection remains so long how both connections are off-hook every time frame 2 occurs. The hanging condition one or both connections is determined when one or both participants disconnect break up. This is reported back to processor 304, which then causes the memory to perform a write operation to restore the assignment between frame 2 or time slot 2 as well as each of the connections.

Detailed description Flg. 4, 5 and 6

In the FI g. 4, S and 6, which correspond to FI g. 7th belong together, are further details of the invention Plant shown. 4 essentially contains the details of the processor including the program memory and the decoders and gate circuits assigned to the memory. In addition, FI g. 4 the comparator that controls the logical Performs operations of the processor. Flg. 5 and 6 contain d <: n rest of the appendix including the Hardware memory and the circuits that effect the exchange of information between the memories. In the lower right corner of Flg. 6 are the Zcltmultlplcx collection 619, the attached Line switch 612 and the ones with the

Telephone sets connected to line switches 632-illustrated L.

The speed at which operations are carried out in the facility is determined by the 1 MHz oscillator 501 of the usual construction. The oscillator drives the tent position counter (SC from slot counter) 502, the 64 payment positions marked 0 to 63 possesses, and for each cycle of the oscillator 501 worlds one position. The counter 502 is a binary ■ The counter and the current position of the counter indicate the time slot currently being served by the system. The counter 502 provides an output signal over the line 502 * 4 to the left input of the time slot address memory (SAM) 507. In addition, the counter 502 provides an output signal that corresponds to its instantaneous Status indicates via line 502B to the comparison circuit 503

The frame address counter (FC) 504 is set according to the following Description advanced once every 65 microseconds and indicates the current frame count, i.e. H. the time slot, their conversation information Processing at the moment. The payer is 504 also a binary counter and has 64 positions, which are labeled 0 to 63. The current status of payer 504 is via line 504/4 to comparison circuit 503 and via line 504B given to an input of the gate circuit 514. The comparison circuit 503 gives an output to the Line 503/4 if the status of the time slot counter 502 corresponds to that of the frame counter 504. The output signal on line 503/4 you will get to Zeltlagen-Loglkschali'iir.g 505 which, as discussed below, perform a number of functions one of which is the payer 504 with each occurrence of a new frame to advance one position. The comparison circuit 503 can be any conventional comparator, for example as explained on page 99 in the book by Mano "Computer Logic Design", edited by Prentlce-Hall (1972).

The description of the system begins with the assumption that the system is currently connected to a call processed for the time slot 1 and that accordingly the frame counter 504 is currently the Numerical value 1 displays. This 1 is given to the comparison circuit 503 via the line 504/4.

The comparison circuit 503 is intended to determine when the tent position counter 503 is in the same position as the frame counter 504. If this state is present, the comparison circuit 503 outputs a signal via the wire 503/4 to the // input of the time-position logic circuit 505. The D output signal of the position-position logic circuit 505 has a delay of one microsecond with respect to the H- Entry signal. After this delay of one microsecond, a pulse is transmitted from the D output via line 506 to the right input of the frame counter 504 in order to advance it by one position.

As already mentioned, it is assumed that the frame counter 504 is in position 1, that the time slot counter 502 is in position 1 and that the comparison circuit 503 determines that both counters are currently 1. In Flg. 2 This condition is represented by the third layer of tent, marked 1 on the upper cell. At the beginning of this occurrence of tent layer 1 is the system in frame 1 according to the information in the tent diagram for frame 1. The comparison circuit 503 generates an output pulse at the beginning of this occurrence of tent layer 1 and transmits this pulse to the time slot logic circuit 505. After a delay of one microsecond, the circuit 505 generates a pulse which advances the frame counter 504 by one position to position 2. This brings the system to frame 2 state. In which it can process call connections that are assigned to tent layer 2, or can carry out other work if no call connection is assigned to time slot 2 at the moment.
The oscillator 501 switches the tent position counter 502 by one position to position 2 to the same tent to which the output signal of the tent position logic circuit 505 brings the frame counter 504 to <* position 2. This state is shown in FIG. 2 by the penultimate tent layer designated by 2. It is shown there that the beginning of this time slot coincides with the beginning of frame 2. The upper output signal of the time slot counter 502, which now represents a 2, is transmitted via the line 5024 to the left input of the SAM memory 507. This memory is a memory with arbitrary access, which has a word position for each tent layer. The memory responds to the arrival of tent location information at its left input and gives the current content of the word for Zeitlagc 2 to the

Bus 50 & 4.

According to the following explanation, the the respective contents of the SAM-Spelchers 507 for each time slot the current state of the call connection again, which is served during the Zeit'age.

Accordingly, the content of word 2 gives the memory 507 the current state of the conversation which is operated during the tent position 2. When a 2 arrives at his left entrance via the Line 502/4 is the memory 507 information In coded form to the manifold 508/4, which the. represent the instantaneous state of the call connection served by time slot 2. This information are hereinafter referred to as the conversation status word or conversation status.

4) The call status word given to the bus 508/4 is generated via the AND gate 509 under control of the S output of the tent location logic circuit 505 and then via the bus 508B to the lower input of the gate 402. The B pulse at the input of the OR gate 401 passes through this gate and then goes to the upper input of the gate 402 so that the information on the bus 508S can pass through the gate 502 and enter the program (P) counter 403 . The P counter contains the address counter for the program memory 404. The P counter 403 can consist of any known flashing counter, for example as explained on page 188 in the above-cited book by Mano. The program memory contains a plurality of sub-programs, the memory address of the first word of each sub-program being a call status word. Conversely, there is a sub-program for every possible call status of the system. The setting of the P-

fi5 counter 403 to the current call status for the tent position 2 represents a command for the program memory is to continue to the address of the subroutine assigned to the call status.

1?

The execution of a program causes information signals from the various fields of the Program memory are given to the lines, which lead down from the various sections of the memory indicated in the figure.

It is assumed that the current conversation status for time slot 2 is the status "free" indicating that time slot 2 is not currently serving a call. In in this case the status word »free« is entered in the P-counter 403 given, via line 5085 and members 509 and 402, as already described. The status word »free« represents the start address of a Number of words in program memory that contain the »Form the system's frete subroutine. This The subroutine causes the system to carry out the work functions assigned to a free tent layer. One of these functions is the scanning of free connections (line switch 612) for the purpose of detection the identity of each subscriber station that has a service requests. This function is carried out under the control of the connection address counter (PAC) 602 in FIG.

The payer 602 has a position for each connection 612 on the time multiplex collecting line 619. The current status of the payer when a free time slot is encountered reflects the address of the connection which was scanned during the processing of the last free time slot. The PAC counter 602 receives control signals / 4 and / 16 from the I / O decoder 4OC. n-Steuürsigr-) l answers. In the preferred embodiment, a binary address field of five bits is decoded into 16 control signals. An incoming signal via the line IA switches the PAC counter 602 by one position. An incoming signal via the line / 16 cancels the counter 602. In the present case, the I / O decoder 406 sends a pulse to the line / 4 to advance the PAC counter 602 by one step in preparation for scanning the next connection. It is assumed that the counter 602 initially had the count value 7 and is switched to the count value 8 by the I / O decoder, corresponding to the connection 7 or connection 8.

The content of the PAC counter 602 now becomes parallel Via AND gates 630 and 605 to the connection address buffer 606 which contains a number of flip-flops. This transfer is done with the help one to the G3 input of the AND gate 630 from the control members 405 applied pulse and one Z7 pulse given by the OP decoder 407 to the AND gates 604.

The 8 stored in the connection address buffer 606 is then transferred via the bus 609 to the hang-up selector circuit 610 transferred. This circuit contains a multiplexer, the result of the Output 615 connected to that input line 611-connected, indicated by the port address information on line 609. The lines 611- lead from the hook-in selector circuit 602 to a respective line switch 612-. Each line switch continuously sends a signal to its line 611-, which indicates whether the counter is currently occupied or free. When the connection address 8 arrives The hang-in selector circuit is on line 609 610 from its output 615 a signal which reflects the state of the line 8. This signal will via the AND gate 613 and the line 614Λ to Comparison main line 512 out. This goes to

s Input of the! Comparator 409 in Fig. 4. The comparator picks up the signal sent out by the hang-up selector circuit 610 and occurs on a still treading way under control of information from the comparison field of the program memory 404

ίο in action to provide the necessary at that time carry out further operations on the system.

It is assumed that a notice signal for the Terminal 8 has been brought from the off-hook circuit 610 to the comparator 409. The comparator

is 409 can be any known comparator that is also used for the comparison circuit 503 can be used. Of the

Comparator compares that of the hanging selector

. Circuit 610 receives incoming signals with signals that come from the comparison field of the program memory 404, and outputs a signal via the line 409/4 to the exclusive-OR-Güsd 411, which indicates whether a match has been found or not. The other input of the exclusive OR element 411 is connected to the W field of the program memory 404 and, as will be described in more detail later, enables the signal from the W field together with the system signal arriving from the comparator field to be determined whether the incoming signal from the hang-up selector circuit 610 represents an on-hook condition or an off-hook condition. The output line 41 \ A of the element 411 leads to the OP decoder 407 which, together with the information in the OP field of the program memory 404, can control the voltages given to the wires Z1 to Z8. The OP decoder 407 is a conventional I-off / i decoder, which is acted upon by the clock generator 407 and excited via the line 41L4.

The comparison collective timing 512 1st with many different circuits tt the system connected. The timing and order in which these various circuits present output information enter the bus, is controlled by the comparison field 408 determined. This is a standard 1-out-of-n decoder for the I / O decoder 406 described type. The controller 408 has a number of outputs labeled C1 through C12 and are each associated with a different circuit. The order in which the C outputs are activated by the program determined when it progresses from word to word of the respective controlling subroutine.

The comparison field control gives at this tent point 408 a signal on the line Cl to the BIM spelcher 510 to excite. At the moment there is an 8 at its input indicating port 8 from the port address buffer 606 at. Due to the Cl pulse from the comparison field control 408, the element 511 is excited, to read out the current content of word 8 in memory 510, which indicates whether port 8 is at a previous scan was busy or free. This information goes to comparator 409 which points to similar Catfish as with the determination of the hanging condition determines whether port 8 was busy or idle in the previous scan. Suppose

(<s that terminal 8 was free during the previous scan and that corresponding information was given by the BIM spelcher 510 via the gate circuit 511 to the comparison bus line 512. It is also

it has been assumed that the current state of the connection 8 represents an off-hook state. This hanging status can mean a new operating request or a lightning strike or a noise disorder.

The following describes which catfish the The system determines whether the current status of port 8 is a valid service request represents. Recall that the frame 2 is available for this occurrence Processing tent is only 65 microseconds. Be it also noted that typically a minimum of 4 milliseconds is required to determine whether a Connection is a valid operating requirement and is not a blink or noise. Therefore, this determination cannot be made during the only 65 microsecond occurrence of the frame 2 take place.

Partial catfish summarizing it should be noted that the Campsite section 2 of the SAM memory S07 currently contains a status word free, which indicates this is that the time slot 2 is currently not serving a call. For this occurrence of the Frame 2 has been described as the connections can be sampled under control of the PAC counter 602. It has further been assumed that the scanning of port 8 has shown that the port is off-hook and that it is Possibly a new Bedle-η unsanction can represent. In these circumstances it is now necessary to use the conversation state word for tent position 2 In the SAM-Spelcher 507 change from »free« to »check status«. the different conversation state words in the SAM-Speleher 507 consist in practice of various BIt combinations. However, instead of these combinations, it is advisable to use the combinations indicated in each case State of the call.

The frame counter 504 is currently at 2 and then gives an output signal, which represents a 2, via the line 504/1 to the right input of the SAM memory 507. This input is used to control the addressing for a write operation of the memory. The left input 502/1, which is connected to the output of the tent position counter 502, controls the addressing during a read operation. If the address 2 is applied to the right input for a write operation, the program memory 404 and the I / O Dscoder 406 now generate a signal on the line / 15 and apply it to an upper input of the SAM memory 507. The frame address and terminal address portion of the program memory 404 now provide that combination of bits "represent check the status word" Elnhängezustand, to the manifold 412. controlling the said two address fields normally the control members 405 in order to generate the signals applied to the lines Gl to <711 will. The control units 405 contain a conventional I / O decoder of the type described for the I / O decoder 406. At this point in time, however, the information in the two fields represents the new status word that is to be written into the SAM memory 507. The new status word "check suspension status" is now transferred from these two ^6} fields together and via the bus 412 to the upper input of the memory in order to write the status word into tent layer 2.

The attachment test word includes the binary address of the first word of a hook-up check subroutine in program memory 404. The hook-up check subroutine causes the system to carry out the necessary for a call connection in the connection test state Perform work functions. A call connection is in the line-checked status from Point of focus of the determination of a possible condition request up to the tent point at which the system determines whether the off-hook status is a valid operating request represents or not.

The following describes how the system assigns the connection 8 to the tent site 2 or, in other words, how the system stores information indicating that the time slot 2 serves a call connection assigned to the connection 8. Information indicating this relationship is stored by PAM spelcher 513 which contains a word for each port. At its left input the memory currently receives an 8 from the connection buffer 606. The processor then writes a 2 representing the frame 2 into the speaking time slot field of the word for the connection 8. The 2 comes from the frame counter 504. It runs via the gate circuit 514 with the aid of a C1 signal and is entered into the frame address buffer 515. This buffer essentially contains a group of flip-flops which store the respective frame count. Subsequently, at a point in time determined by the processor 304, the frame count value 2 is entered from the frame address buffer 515 by a Z8 signal via the gate circuit 516 and via the bus 517 into the speaking time slot field of the word for the connection 8. This is done under the control of a write signal from I / O decoder 406 on line Π.

After the program has set the frame count 2 in has written the talk time slot field of the PAM memory 513, a busy flag becomes in the BIM memory 510 to indicate that port 8 is currently busy. this will achieved by changing the address of port 8 to the Collective line 609 given to the left side of the BIM counter 510 and a busy mark in the Word portion for the terminal 8 of this memory under the control of a signal on the line 13 from I / O decoder 406 is written. The registered mail an occupied mark in memory 510 is to ensure that no other pitch is attempting makes to operate port 8.

At this point it is required that a 2 be written to the appropriate section of PIP memory 601. This memory controls the line switch t-12- in such a way that each line switch involved in a call connection is switched on and connected to the tent multiplex bus 619 during the time slot assigned to the call connection. For the call connection now described, it is assumed that it is assigned to tent site 2. A 2 must therefore be written in the section for connection 8 of the PIP memory logger 601. It does this in the following way. A 2 is applied to the S input of the multiplexer 620. This 2 passes through the multiplexer r-um lower input of the PIP player 601, if it is not blocked by a / 8 signal from the I / O decoder 406, which is not available at this point in time. fis there is now an 8 from the connection address buffer 60 <> at the left input of the PIP memory 601 via the bus

609 at. At a suitable time point during the frame, a signal at the / 1 input of the PIP logic circuit 617 sets a flip-flop. Thereafter, during the last microsecond of frame 2, when both the tent position counter and the frame counter have the number value 2, the comparison circuit 503 generates a signal at its output D and sends this signal D to the right input of the PIP logic circuit 617. This signal D gives, together with the previous setting of the flip flop, a scramble signal to the PIP memory 601 for writing a 2 into the word for the connection 8. As described in detail below, during each subsequent occurrence of the tent location 2 a 2 is generated at the 5 entrance of the multiplexer 620 is applied to the lower input of the PIP memory in order to cause this to carry out a content-dependent search for the purpose of determining all connections that are currently assigned to Zeitiage 2. As a result of this search, the memory sends a signal to its output lines 621-, which are connected to line switches which, at the moment of the tent location 2, operate the call connections assigned to the tent location 2. These signals excite the switches and connect them to the Zelimultlplex collecting line 619 while the tent is in position 2.

Writing a 2 into the Terminal 8 section of the PIP spelcher 601 functionally assigns the Connection 8 to time slot 2, so that the line switch assigned to connection 2, i.e. the line switch 612-8, connected to the tent multiplex collection line 619 every time the tent layer 2 occurs will.

It has been described in the foregoing how a tent sheet 2 representing 2 In the Port 8 section of PIP memory 601 Has been and how this has been during the last Microscopy of those 65 microscopic studies happened Is that represent this occurrence of the frame 2. the Plant now leaves frame 2 and turns to the implementation of work for other tent layers. The frame payer switches to 3 welter and the System carries out all the work that is required for a call connection that is currently while time slot 3 is served. The tent position counter 502 represents the control device which the The end of the frame tent is determined because it runs through a complete cycle during each frame time and during the 65th microsecond of a frame, comparison circuit 503 establishes a match between the tent position counter and the frame counter and then brings the system to the next Frame.

After leaving frame 2, the system carries out work for all frames following frame 2 and then works for frames 0 and 1. At the end of frame 1 and when the time slot counter 502 is in position 1, the comparison circuit 503 receives both A 1 at both its upper and lower input and, after one microsecond, the tent position logic circuit 505 switches the frame counter 502 one step further to position 2. It also supplies a pulse at your output B. At the point in time at which the tent position logic circuit 505 generates the output signal B , the row position counter 502 has moved from position 1 to position 2, and the output signal D of the tent position logic circuit has the frame counter brought into position 2. The 2 from the time slot counter is now applied to the left input of the SAM spelcher 507. This causes the memory to send the current status word for the ZelMage 2 to the bus SOSA . The output signal B s of the tent location logic circuit actuates the gate circuit 509, so that the status word is applied to the lower input of the gate circuit 402 via the bus 508B. Its upper input is excited at this point in time by the fl pulse given to the gate circuit 401. The actuation of the gate circuit 402 brings the status word of the Zettlage 2 into the P-counter 403. The current status word of the tent position 2 is the >> attachment test- "status word, whose bits the address of the first word of the" attachment test "-

IS subroutine in program memory 404.

A 2 from the frame counter 504 runs over the Bus 5040, under control of the GH signal from the control members 405 via the gate circuit 514 and enters the Rshrnensdrssssnpuffer 515 thinly.

From there, the 2 via the gate circuit 516 is below Control of the Z8 signal from the OP decoder 407 to the upper input of the speech time slot field of the PAM memory 513 given. At the same time, a / 8 signal is sent from the I / O decoder 406 to the right input of this Storage delivered. This causes the memory to carry out a content-dependent search, to determine that connection memory word which contains a 2 in A. * j {enbllck. It was accepted been that the terminal 8 of the tent layer 2 is assigned. Therefore, the memory provides during the content dependent Find out that the Sprehzeltlagefeld for the Terminal 8 contains a 2. De / Speicher 513 then gives the connection number via its output line 518 to the gate circuit 519. The connection number, which at In the present example an 8 is, via the gate circuit 519 under control of the Cl signal from the control belts 405 out and to the collecting line 603 given. From there, the connection number goes through the gate circuit 605 under the control of the Z7 signals and enters port address buffer 606.

After entering the 8 in the connection address buffer 606, it is via the bus 609 downwards transferred to mount selector 610. This then applies a signal to its exit 615 that the indicates the current monitoring status of the line switch for port 8. This monitoring status signal is sent to the bus via gate 613 under control of the C5 signal

so 614/4 and then to the comparison collection 512 which leads to the comparator 409.

If the port 8 is in the suspended state, so program memory 404 in processor 304 would respond to the hang-up signal and the state "Free" in the status word in the section of the SAM spelcher Register 507 for tent position 2. In addition, there would be an indication in the BIM memory 502 Write "Free" to indicate that port 8 is free. Finally, it would display the frame 2 for remove the port 8 portion of the PAM 513 treatment tent sheet field.

It is assumed that port 8 is still off-hook. This information is from Comparator 409 added and together with the

<> 'from the Einnahmepröf original program is used to determine that the state of port 8 represents a valid service request. The described Plant works on the assumption that two

consecutive notice displays at an interval of 4 milliseconds (distance between two consecutive following appearances of the same frame) represent a valid operating requirement.

After determining that it is a valid operating request, the system writes the new additional word "Register request" in the tent location section VI 7. of the SAM memory 507. This is done by applying the status word "Register request" to the upper input of the memory 507 via the Line 412, by applying a signal / 5 from the I / O decoder 406 to the memory and by applying a 2 to the right side of the memory from the frame counter 504. The subroutine "Register request" controls the operations of the system that are used to connect an outgoing Register to the call connection are required.

The next time frame 2 occurs, the status word “register request” is read from the SAM memory 507 and sent to the P counter 403. This brings the »Register request« subroutine to the control of the system. Two outgoing registers 622- / 4 and 622-ß are shown in the drawing. An outgoing register is connected to the multiplex bus 619 in that the port address of a free outgoing register is placed in the port address buffer 606. This address is obtained from the memory 624, which receives a C6 signal from the control elements 405 and then gives the address of a first register via the gate circuit 623 to the bus 603. From there, the information is transferred to the connection address buffer 606 under the control of the gate circuit 605 and a Z7 signal. The left output of the port address buffer 606 provides the bus 609 and the PIP spelcher 601 with the port address of the outgoing register in order to prepare it. Then, when the tent position counter 502 is again in position 2, a 2 is written via the multiplexer 620 into the connection word of the PIP memory 601, which is assigned to the selected register. The 2 is written into the connection address word in the same way as the 2 is written into the connection address 8 assigned to the calling subscriber line. It is assumed that the address of port A is written for register 622- / 4.

Processor 304 writes after selecting the register a new status word »dial tone« in the time section 2 of the SAM memory 507. Then Dial tone given by tone generator 618 to the subscriber line during each occurrence of tent site 2. The tone generator 618 generates the various types of tone signals required by the system, for example ringing tone, dialing tone, busy tone, etc. The type of tone signal generated is determined by the Generator controlled by input signals applied to section 508C of bus 508. The manifold 508C is part of bus 508 that receives outputs from SAM memory 507. at The SAM memory gives every occurrence of a tent location 507 the status word on the bus 508Λ, the indicates the current state of the time slot. With each occurrence of a tent location, the one Im state "Dial tone" is used, a "dial tone" status word is sent to bus 508/1 created. During each such occurrence, the binary digits of the status word "dial tone" go to Input of the tone generator 618. The binary digits contain address information and for the tent of one microsecond of the tent position, they cause the tone generator to send a dial tone to the tent multiplex

s create collecting line 619. Only line switch 8 is under control of PIP circuit 601 during the tent layer 2 is closed, and consequently only the listener of the calling subscriber is on the subscriber's part 8 connected to the tent multiplex manifold

ίο and only this subscriber can now use the dial tone hear.

So it becomes the SAM memory 507 under the control of the tent position counter 502 by one position every microsecond switched on, and during each interval

The memory 507 outputs one microsecond to the Bus 508 the current status word for the indicated by the reading of the counter 502 Tent location. The bus 508 is with the tone generator connected, which is caused by its logic circuits to generate that tone signal, and to be applied to the tent multiplex bus, which is determined by the status word on the bus 508 is required, provided that the status word requires the application of an audible signal to the bus.

FQr the connection under consideration, which during the frame 2 and the tent layer 2 is operated and is currently in the »dial tone« state, So a dial tone status word is applied to the bus every time the tent position counter 502 Goes to position 2. At this point in time, the tone generator 618 receives the "dial tone" status word and gives a dial tone to bus 619 for the one microsecond interval that each Occurrence of the tent location 2 is assigned.

Terminal 8 of the calling line and terminal 8 of the register are connected to the time-division multiplexing message line during time 2 under the control of FIG has been. This causes the memory to carry out a content-dependent search and to apply a signal to each output line 621- which is assigned to the connection word which contains a 2. Since this currently applies to connecting words 8 and A , lines 621-8 and 6H-A are energized, which give a signal to line switches 612-8 and 612- / 4 to energize these line switches and during, to connect each occurrence of the tent layer 2 to the time multiplex collecting line. As a result, the subscriber at the subscriber station 8 can hear the dial tone applied to the tent multiplex collecting line during the tent location 2. In addition, the calling subscriber is connected to the outgoing register 622/4.

The system then leaves frame 2 and goes to perform work functions for others Call connections over which are assigned to other time slots and frames.

ω Near the end of the next occurrence of frame 1, comparison circuit 503 generates a Correspondence indicator at its output if both the frame counter 504 and the tent position counter 502 are in their position 1. A microsecond

ό5 later the magazine counter 502 advances to position 2. The tent location logic circuit 505 generates an output signal which brings the frame counter to its position 2 and sends a signal on its line B,

to get the status word currently on bus 508 into P-counter 403. The status word on the bus 508 is the status "dial tone" for the tent layer 2, since a 2 from the tent layer counter is applied to the left side of the SAM-Spelcher 507. At the same time, the time slot counter 502 sends a signal 5, which indicates a numerical value 2, to the line S, which leads via the multiplexer 620 to the lower input of the ΡίΡ-memory 601. This 2 causes a content-dependent search in the memory 601, which then applies a signal to all output lines in which a 2 is contained in the assigned connection memory word. Since line switch 612-8 and outgoing register 622-8 are associated with the connection, a 2 has been written into the port memory words of memory 601 associated with those ports. Accordingly, at this point in time, the output lines 621- for these terminals will be energized to close switches 612- / 4 and 612-8 and connect register 622-A to the calling party. This hears the dial tone at this tent point, since the status word "dial tone" appearing on the bus 508C is pending at the input of the tone generator 618 and the tone generator then applies a dial tone to the tent multiplex collector. In addition, the status word "dial tone" in the P counter brings the program memory 404 to the first word of the "dial tone" subroutine at this point in time.

If the frame counter 504 is in position 2, information relating to the number 2 represent, via the gates 514 to frame address buffer 515 and from there via the gates 516 and line 517 to the lower input of the talk time slot field of the PAM memory 513. Together with the signal ffl, this information causes the memory 513 to carry out a Content-dependent search for the purpose of determining the subscriber connection, which is assigned to the Zettlage 2. In the assumed case, this is the connection 8, so that the memory 513 at its output an 8 to the input of the gate circuit 519 and via the line 603 as well as gate 605 to port address buffer 606 provides. From there the port address information is supplied to the input of the mount selector 610 which returns a signal indicating the current States of the subscriber circuit 8 indicates. It is assumed that the terminal 8 is still Im Is off-hook. This information goes through the Gate circuit 613, line 614 and the collecting line 512 to comparator 509. Processor 304 and program memory 404 can then determine that the connection 8 is still in the off-hook state. In other words, the calling party still has not started voting. The plant leads In In this case, do not do any further work for the rest of frame 2. She leaves frame 2 and goes to work over for other frames. The state described lasts as long as the participant Im The pending state remains and does not begin with the election.

Finally, when the subscriber starts voting, the successive appearance of the Frame 2, an attachment signal from the attachment selector 610 based on the operations already described receive.

When a dialing process is detected, the first function of the system is to switch the dial tone from the time multiplex collection during the next occurrence of the tent layer 2. It does this by changing the Status word for tent position 2 from »dial tone« to »dial« in the SAM-Spelcher 507. The frame counter

s 504 currently puts a 2 on the right connection of memory 507. The program memory 404 now puts the new status word "elections" on the line 412 and a / 15 signal to the upper input of the memory 507. The 2 from the frame payer, the / 15 signal and

ίο the status word »Select« from the program memory 404 together cause a write operation to be performed in the SAM spelcher 507 to store the new Enter the status word »Select« in word section 2 of the memory. Then the tone generator switches

IS 618 the dial tone from the tent multiplex collection 619, since the bits that represent the status word "dial" no longer cause the tone generator 618. Apply some kind of signal to the tent multiplex system. Whenever time layer 2 occurs, while the system is in the selected state, the arrival of a 2 at PIP spelcher 601 causes this to perform a content-dependent search and to actuate all line switches assigned to tent layer 2. For the present call it is assumed that line switch 612-1 for register 622-A and line switch 612-8 for port 8 are actuated. As a result, the calling subscriber at connection 8 is connected to the outgoing register 622-A during each occurrence of the tent location 2, so that the digits for the call number of the called subscriber can be entered in the register.

For the remaining parts of the system, the only work function during time slot 2 and frame 2 is to check the output signal of the outgoing register A , which is given via the gate circuit 643 and the line 6140 to the comparison collecting circuit 512. With this signal, the program memory 404 can determine whether the calling subscriber is still dialing or whether the register has encountered a dialing state. If the selection is still being made, the program does not initiate any further work during frame 2. Finally, the outgoing register 622- / 4 supplies an end-of-dial signal to the gate switch.

• »s tion 643. This signal is transmitted via the collecting lines 614 and 512 to processor 304 to indicate to program memory 404 that the voting is finished. At the same time, the outgoing register provides the digits representing the dialed number

so output line 625 leading to the lower input of the TAM-Spelchers 626 leads. This memory contains the Information that relates the dialed telephone numbers to the connection numbers. The arrival the number dialed from the outgoing register

ss causes memory 626 to perform a content search and generate an output signal identifying the line number associated with the dialed directory number. The connection number is given to the bus 603 via the gate circuit under the control of a GI signal and is input to the connection address buffer 606 via the gate circuit 605 under the control of a Z7 signal. In addition, the connection number is carried to the input of the hook-in selector 610 via the bus 609. This then returns a signal via the gate circuit 613 and the bus lines 614 and 512, which indicates whether the called connection is busy or free.
The outgoing register is now used by the call

Connection shut down by being an O In Connection word in PIP memory 601 is written. Thereby host! the line switch of the register of ;. Jr tent multiplex collection shut down.

It is initially assumed that the connection called is busy. In this case, the Program memory 404 writes the status word "occupied" into tent layer section 2 of the SAM memory 507. The status word »occupied« is then received from the memory via the bus 508/1 given to the tone generator 618 each time the tent layer 2 occurs. The arrival of this status word causes the tone generator 618 to output a busy tone to the tent multiplex collection line 619 during each Occurrence of the tent position 2 to give. The calling subscriber can then use the busy tone to indicate this hear that the called subscriber is busy. The facility? remains in this state during each emergence the Zcitiagc 2 and the calling party listens the busy tone until it hangs up and gives up the call.

During each successive occurrence of frame 2, the program memory 404 reads the connection number of the calling party from the PAM memory 513 and puts it into the connection address buffer 606, which in turn causes the mount selector 610 to return a signal to the program memory 404 indicating the current status of the calling party Connector reproduces. In this way the program determines whether the calling connection wel'.erhln is hung up and should continue to receive a busy tone, or alternatively that the calling subscriber has hung up and given up the call. If the suspended state is determined, the program interrupts the call connection and brings the activity word for frame 2 and tent layer 2 in the SAM spelcher 507 back into the free state. At the same time, the program writes a Q (which indicates the free state) in the connection 8-Absc! Inltt of the PAM memory 513. The assignment between connection 8 and time slot 2 is canceled. The system also writes a 0 in the PIP memory 601 for all connections that are assigned to the call connection just described. This includes port 8 to be called and port A for register 622- / 4. In this way, the indication of the time slot 2 is deleted from these sections of the PIP memory 601 and the assignment of these connections to the tent position 2 is canceled. At this point in time, the system also marks the connection 8 section of the BIM memory 510 as free. This is done by applying a / 2 signal to the upper connection and the connection address 8 to the left side of the spoke = 510.

It is next assumed that the called connection is free. This is done by transferring the favored Port number from TAM spelcher 626 to port address buffer 606 and by querying the The state of the called connection is determined with the aid of the hang-up dialer 610. After that Program has determined that the called connection is free, it writes the status word "Call" in the SAM memory 507. Assume that the gernfene Subscriber station is connected to the connection 5. In this case, the program writes a 2 into that Speech quotation field for the terminal 5 Im word PAM spelcher 513. The program also writes a 1 in the M section of the port 5 word in the PAM spelcher 513. This I indicates that port 5 is the called port. The 2 in the office tent area of the word for port 5 indicates that port S is currently assigned to time slot 2 Is. These operations are performed while

S the program is in the »Select« state, and before the status word "Call" is written into the SAM spelcher 507. It also marks the lie the connection 5 in the BIM Spelcher SlO as occupied. this happens so that the terminal 5 does not initiate a connection and free for the system during a free Frame can appear before the ringing current is given to the terminal 5.

After the status word »Call« in the time section 2 of the SAM spelcher 507

IS, this word is read out and during each subsequent occurrence of the tent layer 2 is put on the manifold 508. The arrival of the word in the case of the tone generator 618 causes a rufion to be generated and applied to the Zeiirnüiiipiex-Särnmeiicitung during time slot 2. This ringing tone is transmitted back to the calling subscriber as an indication that that the system serves the call request.

Four milliseconds later, namely the next time frame 2 appears, the system is still in the "Call" state and the "Call" subroutine processes the connection. The 2 in the frame counter is transferred to the frame address buffer 515 and passed from there via the bus 517 to the upper input of the speaking time slot field of the memory 513. This signal, together with a / 8 signal from I / O decoder 406, causes this section of the memory to carry out a content-dependent search in order to determine all connections assigned at the moment of time slot 2. The program also supplies a signal to the E input of the M field. This signal at the E entrance together with the Signa! On the bus line 517 both fields together to carry out a content-dependent search to determine the called connection that is assigned to tent location 2, namely the connection for which a 1 is written in its M field and a 2 in its speaking time slot field is. For the case considered here, this is connection 5 and therefore the PAM memory 513 now outputs those bits which define connection S to its output line 518. From there the address information for the

so connection 5 is applied to the left side of the ringing current circuit 628, which together with a ΛΟ signal from the I / O decoder 406 causes the supply of ringing current to the subscriber circuit 5 via the output line 629-5. This causes the alarm clock in the called subscriber set to respond.

Thereafter, during the same occurrence of frame 2, connection address 5 is sent to the hanging selector 610 transmitted, which via the gate circuit 613 and the buses 614 and 512 a signal to

ω Handler 304 retransmits the monitor state of the called connection. Assume that the call is not answered immediately and that one or more consecutive frames are required for calling. to Beginning of each occurrence of frame 2 in which a ringing stream is given to the called subscriber line the program memory 404 applies a / 10 signal to the ringing current circuit 628 and the connection

address 5 from PAM memory 513 to the port address buffer 606 and then to ringing circuit 628. These signals together cause that again a ringing current is given to the line switch 612-5. Each time frame 2 occurs, it also checks the program monitors the status of port 5 to see if the call is now has been answered. The program also causes the PAM spelcher 513 to perform a Content-dependent search for the purpose of determining the calling connection. This is done by creating a 0 to the top input of the M-field and a 2 to bus 517 from frame address buffer 515. Da the calling terminal is terminal 8, the PAM 513 provides an indication for terminal 8 via the gate circuit 519, the line 603 and the gate circuit 605 to the connection address buffer 606. The Port 8 address is then transferred from buffer 606 to mount selector 610, which receives a signal that returns the current hanging condition of the calling party. If the calling subscriber has not yet given up the connection request and is still in the off-hook state, the system continues to operate the connection request away. If the calling party is on-hook and for a predetermined number of times of successive frames while hanging, the system drops the call and places all parts of the memory associated with the connection in the manner already described Initial state back.

It is assumed that the called subscriber answers the next time frame 2 occurs. This off-hook status is returned to processor 304 by on-hook selector 610 to indicate that the call has been answered.

During the same frame in which the off-hook was detected, the Connection address 5 is applied to the left input of the PIP memory 601. A write signal is sent to its upper input under control of a / 8 signal from the PIP logic circuit 617 given. Also will a 2 to the lower input of the PIP memory 601 from the tent position counter 502 via the multiplexer 620 created. These three signals together cause a 2 In the section for port 5 of the PIP memory 601 is enrolled. Thereafter, every time the tent position counter 502 reaches its Position 2 goes, the arrival of a 2 at the lower entrance of the PlP spelcher 601 to carry it out a content-dependent search for the purpose of determining and activating all of the tent location 2 assigned Connections. As a result, these connections are made for the duration of each occurrence of the tent layer 2 with the tent multiplex collection 619 connected. For the present connection, during each subsequent Occurrence of the tent layer 2 the line switch for the port 8 and the port 5 closed because a 2 in those sections of the PIP memory 601 are stored that are assigned to these connections.

The program brings the state of tent location 2 Im SAM spelcher 507 from "calling" to "speaking" when the call is answered. With each subsequent one When frame 2 occurs, the program initiates a content-dependent search at PAM spelcher 513 to read out the identity of connections 5 and 8 one after the other. These information are presented one by one given to the mount selector 610, which then Information to processor 304 regarding the monitoring status of each participant of the connection retransmits. As long as both participants are unhooked

If it remains, the connection and the system run smoothly does not need to initiate any further processes. If one of the participants hangs up and is determined that the state of suspension is a task of the connection and not a lightning strike or a fork

> o is button, the connection is terminated and the allocated memories are returned to the initial state.

Explanation of an operation with multiple registers

In a system equipped with several outgoing registers 622-, the connection address of the register used for a connection is written into the PAM memory 513 in the same way as it is for writing the connection number of the calling or called connection into the memory has been described 1st. On each successive occurrence of the frame serving the connection, a content dependent search is performed in PAM memory 513 to sequentially derive the port address of the register and that of the calling port. The connection number read out during each search is controlled both by the frame number on line 517 and by the bit arriving at the M field via line E from the comparison field of the frame memory 404. A 0 on line E causes the memory to read out the connection number of the calling party. A 1 on line E causes the memory to read out the connection number of the outgoing register when the connection is in the "dialing" state. If the connection is in the "calling" and "speaking" states, a 1 on line E causes the memory to output the connection number of the subscriber called.

Description of the PIP memory 601 The operational status of this store is referenced

to the writing and subsequent deletion of a frame number in or in the connecting word of a outgoing register 622- described.

The register 622- / 4 has the connection address A. It is connected to the line switch 6Y1-A and assigned to connection A of the tent multiplex collecting system 619. It is assumed that the call connection is being processed in frame 2 and is in that set-up state. In which the connection address A is in the connection address buffer 606 and is given via the bus 609 to the left input of the PIP memory 601. The multiplexer 620 works in such a way that, if a / 8 signal does not arrive, the 2 applied to the 5 input of the multiplexer from the output of the time slot counter 502 runs through the multiplexer to the lower input of the PIP memory 601. This causes the memory to perform a content-dependent search for all connections that contain a 2. According to the illustration in Flg. 14 gives for writing a 2 In den

** Terminal A for the register 62Z-A of the program memory 404 a / 1 signal to the PIP logging circuit 617. A fill flop 1412 is set as a result. This should be explained in more detail. Then will

During the last microsecond of frame 2, when the 2 Im Zclilugcnzflhlcr agrees with the 2 Im Ruhmenzahler, this agreement is determined by the comparison circuit 503, which then applies a pulse to the β input of the PIP logic circuit 619. This D signal, together with the previously received / 1 signal, sends a write signal to the upper input of the PIP memory 601. This signal, together with the connection address A from the connection address buffer 606 and together with the 2 at the lower input of the PIP memory, causes the Writing a 2 in that section of memory which is assigned to port A.

When the tent layer 2 occurs, the PIP memory 601 receives the 2 applied to the S input of the multiplexer 620, which causes the memory to carry out a content-dependent search for all words which currently have a 2. As a result, all those output lines of the memory that are assigned to a word that has a 2 are excited. The voltage applied to each such line during time slot 2 output signal completes the associated circuit breaker and for connecting it the duration of the time slot 2 with the Zeltmultlplex manifold 619. For the call described save those parts of the PIP-memory 601, the ports A and 8 FIG. 2 shows and accordingly output lines 621- / 1 and 621-8 are energized to close line switches 611-A and 612-8 during tent position 2. FIG. This causes the connection of the outgoing register 622-A with the calling subscriber during tent location 2.

The system and the PIP memory 601 remain in this state as long as the calling subscriber dials and until an end-of-dial signal is detected. After dialing is complete, the calling party must be disconnected from the outgoing register and connected to the called party. To separate the register from the multiplex collection 619, a / 8 signal is applied from the I / 0 decoder 406 to the right-hand side of the multiplexer 620 when an A for the connection address of the register is stored in the connection address buffer 606. The / 8 signal represents a write command and clears the 2 that are currently in the word for terminal A and causes a 0 to be written in their place. This 0 comes from the "all-zero" circuit 616 and drives to the separation of the register from the calling subscriber, since the line switch 6U-A of the register is no longer actuated during tent position 2.

There are two possibilities by which the PIP logic circuit 617 receives a write pulse. One is given by the sequential application of a / 1 signal (which sets a fill flop) followed by the arrival of a D signal based on a match signal from the comparison circuit 503. The other possibility is based on the arrival of a / 8 signal. This signal itself causes the PIP logic circuit 617 to generate a write pulse. In the multiplexer, the / 8 signal blocks the S signal, i.e. the current position number, and sends a 0 from circuit 616 to the lower input of PIP memory 601.

The arrival of information, for example a 2, at the lower input of the PIP memory 601 without a write pulse at the upper input causes the memory to perform a content-dependent search.

On the other hand, the arrival of a 2 µm lower input causes the l'IP memory 601 together with a write signal at the upper input and a connection address at the left input that the digit on s lower input ta the specified connection address word is written.

Description of the SOM spelcher 513

ίο The purpose of the SOM- (Servlce Option Memory) 531 is to define the class of service to which each line is authorized. For example, if a calling Subscriber dials 9 for an outside call,

IS so its port address would be on the left side of the SOM-Spelchers 531 created, which is then transferred to the Verglelchssammelleltung 512 information there, tile the Show service class to which the calling connection belongs entitled 1st. If the participant is authorized to unrestricted operation, the SOM memory 531 the digits 1000 Via the comparison bus line to the lower input of the! Comparator 509 give. At the same time, the comparison field of the program memory 404 supplies the same digits to the upper input of! comparator 409. If a match is found, a match signal but the gate circuit 411 is given to the OP decoder 407. This match indicates that the calling party is authorized for the service he is currently requesting.

The SOM spelcher 531 can typically be used for any Port address contain a word of 24 bits. This Word »would be divided into a variety of fields and

Only one field would normally be required in each case in order to serve a connection at a certain setup level. In order to output only the digits of the required field onto the comparison bus, the SOM memory 531 has several blanking inputs, in this case four, which are labeled C9 to C12. Each blanking input is assigned to a different field. The arrival of a certain blanking pulse leads the bits of the assigned field to the comparison bus 512. So if the port 8 selects a 9 to initiate a connection, a certain field of the SOM memory 531 is read out to indicate the service class to which the port 8 Is entitled. If, on the other hand, port 8 is called and found to be busy, another field from the word for port 8 can be given to the Verglelchssammelleltung to indicate whether free dialing is permitted for connections intended for port 8.

Description of the HAM spelcher 607

The HAM (Hunting Address Memory = Freel Wahladressenspelcher) -Spelcher 607 is used for free dialing if the first connection to be used for a connection should be used when it is determined to be occupied.

For example, assume that port 8 called and determined to be busy. In this case, the information on the operating possibilities becomes for port 8 is read from the SOM spelcher 531 to see if there is a free choice for connections that are intended for this connection. It is assumed that the free election Is approved. In this case the port address becomes 8 given to the HAM-Spelcher 607, who

circuits 608 and 605 apply to the connection address buffer the connection address of the next, but a free selection to be reached line, for example connection 19. If connection address 10 is in the connection address buffer, the monitoring status of connection 10 is determined by hang-up selector 610 , and if the connection is free, the connection is switched through. If the connection is busy, the connection address 10 is applied to the HAM memory 531, which generates the address of the next connection that is to be checked in free selection and sends it to its output lines. This operation continues until a free connection is found, until all connections in the free selection group have been checked or until the connection has been abandoned, depending on the program.

Description of memory 624

The memory 624 contains the connection addresses of the M Operator places, the American conventions and the outgoing register. For a more detailed description of the memory, it is assumed that a participant has a 9 chooses. Upon finding 9, the program causes memory 624 to be the port address of the first Output trunk transmission, dfa checked for the service of the connection request on the Frel state shall be. This output function is carried out by applying a G5 signal to the memory 624. The arrival of this signal causes the memory to »select the desired. To generate address and via its Output line 6244 to be applied to the input of AND gate 623. The G5 signal also goes to OR gate 631, whose outer signal is then as Another input signal for the AND gate 623 is used, so that the desired address via the bus 603 and the gate circuit 605 is transferred to the port address buffer 606. The memory is working up the same catfishes for conversations with whom an operator station is required. Corresponding « applies if the installation in Freiwahl is looking for a free outgoing register. In case you The connection is busy to the first operator position, the first trunk transfer or the first outgoing one Register is assigned, the HAM-Spelcher depends on the type and structure of the connection 607 is used in the manner already described to determine the connection address of the next circuit or the next connection to be visited and input into the connection address buffer 606.

Description of the tent position logic circuit (Fig. 8 and 9)

55

The tent ply logic circuit 505 will now be described. The circuit has two inputs, the In FI g. 5 are designated by H and A. The output signal of the comparison circuit 503 is fed to the // input. The /! Input receives the & n output signal of the 1 MHz oscillator 501. The outputs of the tent position logic circuit are labeled B and D. The fl output leads to the gate circuits 401 and 509, which supply a load or gate signal for inputting program address information from the bus 508 via the gate circuit 402 into the P counter 403. The D output of the tent location LoRlk circuit switches the frame counter 504 further. In addition, the signal from the D output is applied to the right-hand side of the PIP logic circuit 617 as a control signal.

Fig. 8 shows the details of the tent position logging circuit 505. The ^ input from the 1 MHz oscillator

501 and the // input from the comparison circuit

503 both go to an input of the AND element X. The circuit has a main reset input which is used when the system is started up. The flip-flop FF is reset via this input. Both the tent position counter 502 and the frame counter 504 in page 5 switch due to negative signals. The tent position counter

502 continues to run when a negatively directed signal from the oscillator 501 arrives. The frame counter runs due to a negative-going signal D from the tent location logic circuit welter.

The Fllpflop FF In Flg. 8 Is in principle a common JK flip-flop, which is initially assumed to be in the reset state, in which its 5 output is set to L (low voltage) and its output is set to // (high voltage). Assume that the frame counter

504 has the count value 1 and that at time point 7Ό according to FIG. 9 the tent position counter 502 assumes the count value 1. The output of the comparison circuit 503 goes high at time 7Ή when the comparison circuit detects a 1 h-il two counters. This signal H for high voltage is linked by the AND element X at time Π with a positive signal from the 1 MHz oscillator using an AND function, and the output of the AND element X gives a "clock" input signal to the Fllpflop FF. The flip flop is then set at the instant Tl, namely the beginning of the negative-going edge of the clock signal. The Fllpflop FF is switched in such a way that it works in tilting mode, in such a way that it switches over each time a negative clock pulse is received. The arrival of a negatively directed pulse from the AND element X to the time point TL c & thus alters the flip-flop FF from the reset to the setting state.

It has been explained that there is a delay of one microsecond between the point in time at which the comparison circuit 503 determines a match between the position counter and the frame counter and the point in time at which the frame counter is incremented. This is in flg. 8 and 9 explained. The // signal goes in positive direction when the match is established, namely at point 70. With reference to the 1 MHz signal, the negative-going edge of the D signal occurs one perlode later at time TL and is used for switching on given to frame counter 504. The D signal is first generated at the instant Π with a positive edge of the oscillator and the A signal when the Λ output of the flip flop FF is high.

The frame counter and the tent position counter both move to your next position at the tent point TL. The tent position counter 502 switches directly due to the negative edge of the clock output. The frame counter 504 switches due to the negative edge of the D signal.

The output signal B is generated at time 73 by an AND operation of the clock signal with the S output signal of the flip flop FF . These two output signals are at H at tent point 73 and for half a microsecond thereafter until the clock output signal at tent point TA goes in the negative direction.

The ß-output provides a gate signal that corresponds to the input the contents of the bus 508 into the P-counter 403 allows.

Fllpflop FF switches to the reset state at time point TA on the next negative edge of the clock signal. At the time point TA , both the clock output signal and the // output signal of the comparison circuit start with a negative tendril.

In the call connection described earlier, it was assumed that both counters have the count value 1. The comparison circuit 503 has determined the 1 in both counters and switched the frame counter to 2. The tent position counter has moved to 2 under the control of the clock 501. Although both counters have the count value 2 at this point in time, the comparison circuit 503 does not determine this correspondence due to the circuit according to FIG. 8. The ß output signal switches the frame counter further. This signal can only be generated when the flip flop FF is reset. As FIGS. 8 and 9 show, the filling flop FF is reset when the counters both have the count value 1 at the beginning. The positive edge of the Z) output signal is generated at time Π. The flip-flop FF is set for an interval of one microsecond at time TZ, the negative edge of the D output signal. Since the Flpflop FF remains set for a microsecond (complete duration of the tent position 2), the comparison circuit 503 is prevented from switching the frame counter 504 on at the time TA even though both counters have the count value 2.

Description of the program according to Flg. 10

Flg. 10 shows a typical program used in Plant according to the invention can be used. In detail, Flg. 10 the program for the state »Free« wlede :. This subroutine controls the Installation during the occurrence of each frame, which is assigned to a tent location, which does not have a call connection served. Whenever a frame occurs in the free state, the system has the task of Scan connections of subscriber line circuits in order to determine new operating requirements.

For every tent location that does not serve a connection, 1st the status word "free" is written into the assigned word in the 507 SAM spelcher. At the beginning of the one the frame assigned to the free tent location Status word "free" from SAM spelcher 507 via bus 508 into P counter 403 as the first word of the Frel subroutine in program memory 404. entered. In Flg. 10 correspond to the different columns of the diagram with the exception of the furthest left column "State" the various fields of the program memory 404. Although a 1-to-I match of the fields is available, appear them not in the same order from the left to the right, since In FI g. 4 the memory essentially is shown on the basis of its components, while In M Flg. 10 the program is shown as it is by the programmer written before assembling into bits and entered into memory 404.

The "State" column in Flg. 10 is essentially a column for comments and does not correspond to any field in the memory. The different lines in Flg. 10 represent memory words of the subroutine »Free«. These cells are numbered 1 to 15 to facilitate the Understanding. The designations do not represent any bloom addresses that can be used after assembling the Program and input Could be in binary form in the program memory.

Word 1 of the subroutine in Flg. 10 is labeled “Free” in the “Status” field and the address of this word is received in binary form from the SAM spelcher 507 and entered into the P counter 403. The command in the OP field of this word is denoted by DTA and, according to FIG the system required gate functions are required. These functions carried out by the OP decoder 407 include entering the address of the next command in the P counter 403. The "next address" field of word 1 contains a 2nd flag. 4 shows that this second control of a Z2 signal but the gate circuits 416 and 402 is led to the pump 403.

The command PAC in the field "connection address bus" is applied to the control elements 405 in order to generate the signals required to carry out gate functions on the lines Gl to GIl. As an example, it has been explained how the contents of the port address counter 602 were entered into the port address buffer 606 to initiate a port scan operation. F i g. 6 shows that the transmission of the information from the connection address counter 602 to the connection address buffer 606 requires a G3 signal at the AND element 630 and a Z7 signal at the AND element 605. The G3 signal is generated under the control of the PA C command in the "Connection address collection" field and the Z7 signal is generated under the control of the DTA command in the "OP" field.

For the program now described, the content of the connection address counter (PAC) 602 represents the connection address of the next connection which is to be scanned to determine a possible operating request. At the end of the tent for word 1 and under control of the P counter 403, the program continues to the next address, which according to Flg. 10 a 2 1st. This address contains a further command DTA which causes a 3 to be entered in the P counter 403 as the next address. The indication “Advance PAC” in the I / O control field switches the path address counter (PAC) 602 by one step by causing the I / O decoder 406 to generate a / 4 signal.

The program then runs to address 3 welter, which contains a command of the DEC type. The purpose of this command is, with the help of the! Comparator 409, to generate a binary? To make a decision. The purpose of this decision is to determine whether a certain system condition exists or not. The “fork switch” command in the CC field generates the signals on lines C1 to C12 that are required to carry out the ZM at this point in time. The command "attached" in the W field sends a signal to the upper input of the exclusive OR gate 411. This signal is such that an exclusive OR condition with reference to the output signal of the comparator 409 is created at this point in time wlr4, which is applied to the lower input AdAA of the element 411. The command »Mounted« in the columns M and P in the field »Compare« supplies information to the comparator

409 such that the comparator generates a signal indicating a match when the port being scanned is pending. If the port being scanned is on, a match is determined and a match signal is applied to the lower input 409A of gate 411. This signal and the input signal applied to the upper input of the element 411 from the W field cause the element 411 to send a signal via the line 411/4 to the OP decoder 407 in order to cause the latter to send a Z2 signal produce. This signal brings address 7 in the "Next address" column via GTLED 416 to P counter 403. Address 7 is a "wait" command in which the program does nothing for the duration of the frame.

In the previous paragraph it was described how the program worlds from word 3 to word 7, if the connection being scanned is being picked up as fcstgcstcü:. Alternatively se! now suppose that while the system is at word 3, the port being scanned is found to be off-hook. In this case, the exclusive-OR equation 411 does not set a corresponding condition and instead the OP decoder 407 generates a Z4 signal that the P-counter advances by 1 and brings the program to word 4.

Command 4 causes the system to query the Busy Free (BIM) memory 510 to determine whether the line being scanned was busy or free when it was last scanned. The command BlM in the CC field causes the comparison field control circuit

408, voltages to the C lines for implementation to create the gate functions required for this tent point. The Generation of a Cl voltage, which is given to the element 511, in order to determine the content of that word Im BIM memory SIQ .. that of the scanned connection is assigned to transmit to the lower input of the comparator 409. This information gives the busy-free status of the port being scanned during the last scan. The command »busy« In the W field supplies the required signal to the upper input of the exclusive OR gate 411, such that the gate generates an output signal when that terminal is occupied on the last scan was. The "busy" command in columns M and P of the comparison field shows a busy status Signal to the upper input of the comparator

409 so that this indicates a match if the line was busy on the last scan was.

If the line was busy the last time it was scanned, gate 411 is received on both inputs true signal and then gives a related one Signal to the OP decoder 407. This then generates on its lines Z1 to Z8 the to carry out the required gate functions required signals. To the functions carried out at this tent point includes the transfer of a 7 from the "next address" field of the program memory via element 416 under the control of a Z2 signal and via the element 402 to the P counter 403 to convert the program to command 7 to continue. Command 7 is a "wait" command, with which the program runs for the duration of the Frame does not have any functions.

The meaning of the jump from command 4 to command 7 is that in command 4 the connection that is used in was determined to be occupied during the current scan, also as occupied during the last scan has been determined. Therefore, the current busy status of this connection is not considered to be the new one Operating requirement interpreted. Instead, it can be a line or port that in another tent position is in the speech state. One such a line or such a connection does not require any service by this subroutine. Therefore the program goes to command 7 welter and the

ίο The system waits for the start of the next frame to operate a different call combination.

Assume now that the BIM spelcher 510 indicates that the busy line being scanned was free when the last scan was performed. In this

If this is the case, element 411 does not receive a signal for an applicable one Condition and its output signal controls the OP decoder 407 in such a way that it sends a Z4 signal for the purpose of advancing the P counter 403 by one position to the command! 5 sucks.

A DTA command corresponding to In addresses 1 or 2 carries out the operations specified in the control fields and also switches the program to the address that is specified in the »Next address« field. This next address for a DTA instruction can be the next word of the subroutine. Alternatively, it can also be another word in the subroutine. The command DTAR, for example at address S, performs the same function as the command DTA with the exception that it also

Μ the content of the P counter 403 is transmitted to the RS counter 410, in which ?, the address format is stored for subsequent use. The RS payer 410 can be any conventional storage register or payer. In the usual programmer terminology, the command DTAR can also be referred to as a request for a subroutine.

With reference to the command DTAR in the word S and the functions executed in it, it should be stated that the command FC in the right-hand column of the field "tent position status" causes the content of the frame counter 504 to be transferred to the frame address buffer 514 via the element 514. The word S also writes a 2 for the frame number in the connection address word 8 in the connection address memory (PAM) 513. This is done jointly by the command “Write PAM” in the I / O control field and the command “Write 0” in columns M and P of the »Compare« field and a command »Write office tent position« in the CAM field. The writing of a 0 in the P and M sections of the PAM memory 513 indicates that port 8 is the calling port. The command “write talk tent position” causes the 2 in the frame address buffer 515 to be transmitted via the element 516 and the bus 517 and to be written into the talk time slot section of the PAM memory 513. At this point in time, the corresponding signals for the execution of a write operation are applied to the control lines of the PAM memory. This includes a / 7 signal from the I / 0 decoder

«J 406. The connection address buffer delivers at this point in time 606 the address of the connection 8 to the left input of the PAM memory 513, so that the 2 In the Connection 8 section of the PAM memory word will.

In summary, the function of the program command 5 is to provide the corresponding information into the connector 8 section of the PAM memory 513 to indicate that port 8

is now assigned to the frame 2 and the tent 2.

The next address is word 8 of the program in Flg. 10, namely a D77? Command. This command executes the work specified in the I / O control field and then transfers the content of the RS controller 4HO to the P controller and advances the P counter 403 by I. In the present case, the RS-Reglster saves an S, since the program has jumped from the command DTAR of the word 5 to the command DTR of the word 8. After the I / O control field function is executed for word 8, the S im RS controller ^ iO is transferred back to the P counter 403, which is then incremented by 1 by the signal Z4, so that the subroutine opens the word 6 goes.

With regard to the DTR command of word 8, it should be explained that the "Set BIM" command marks port 8 in the BIM memory 510 as busy. The information which identifies the connection 8 now arrives from the connection address puifer 606 via the bus 609 and is applied to the left input of the BIM memory SIO. The signal that is required to mark this connection as busy is received by the I / O decoder 406 and is a / 3 signal as shown in the drawing. This signal is generated by the I / 0 decoder 406 with the help of the “Set BIM” command. The command DTR in the OP field causes the OP decoder 407 to apply signals with the required combination to the output lines Z1 to ZS . The busy marking of port 8 in the BIM spelcher 510 prevents this port from being occupied during another tent location.

After performing the work function for the DTR command of word 8, the program goes to command 6, as already mentioned. This command is a D7X command. He writes the new state of the call connection in the tent layer 2 of the SAM memory 507. The DTA command in the OP field causes the required combination of signals to be applied to lines Z1 to Z8. The command "Write SAM" in the I / O control field causes signals to be applied to a number of lines / D to / 16 in order to carry out the work functions now required. The entry “Register request” in the “Campsite status” field represents the new status word for frame 2 and connection 2. This status word is transmitted from the field via line 412 to the upper input of the SAM spelcher 507. Then, under the control of the / 15 signal and the 2 applied to the right-hand side of the memory by the frame counter 504, the new status word “register request” is written into the time section 2 of the SAM memory 507. This takes place under the control of FIG. 2 from the frame counter 504 regardless of the position that the tent position counter 502 has at the time of the write operation. In other words, although the timing counter may be in position 45 and apply a 45 to the left input of the SAM memory 507, the 2 applied to the right input from the frame counter represents the control signal at this point in time and causes the status word "Register request" is written in tent layer 2.

The program then proceeds to word 9 under the control of 9 in the “Next address” column of command word 6. Although a status word “register request” is written in tent position 2 of the SAM memory 507 at this tent point, the processor carries out work according to the status word “free”, which was previously in time slot 2, for the rest of the frame time. Another work that has to be carried out when the frame occurs is to go to word 9, which is a DTA command and, with the aid of the "Stan PIP" command, to write in a position 2 representing tent position in the I / O control field 2 Initiated in the port address section of the PIP memory 601. More precisely, the "Start PIP" command causes I / O decoder 406 to send signals

iü to a number of its output bars / 0 to / 16 in order to write the required information about this tent point into the PIP spelcher 601. the end Flg. 6 it can be seen that the generation of a / 1 signal heard that, as already explained, a flip flop In the PIP-Loglk circuit 617 sets. After hiring this fllpflops is made by the match that During the last microsecond of frame 2, a signal is sent to the Ö input of the PIP-Lugikschauurig 617 is created, which is then controlled by the 2nd input to the 5 input of the multiplexer 620 writes a 2 in the PIP memory 601. Im considered Example causes the connection address 2, which is via the bus 609 to the left input of this Memory is created that the 2 from tent position counter 502 is written into word section 8 of the memory will. This has already been described in detail in connection with the component explanation.

The program next loops back to word 7, a wait instruction which causes the processor to do the rest of the frame 2 to carry out no further work.

The next time frame 2 occurs, the status word “register request” from the SAM spelcher 507 is read out and entered into the P counter 403. It causes the program memory to open to pass over the first address of the subroutine "register request", which is displayed as wait !! Ir. Flg. ! Q is shown. This is a DΓΛ instruction which the OP decoder 407 causes the required for this tent point

4fi chen signals Z1 to Z8 to be generated. The command "Search PAM" in the I / O control field causes the I / O decoder 406 to generate the required signals on lines / 0 to A6. The signal FC in the column "frame address bus" causes the frame address 2 to be given to the upper input of the talk time slot field of the PAM memory 513. The command “Search for 0” in fields M and P, together with the command “Find office tent location” in the CAM field, generate the necessary control signals so that the PAM memory 513 can carry out a content-dependent search in order to determine the calling connection that corresponds to the frame 2 assigned 1st. For the example described earlier, this is port 8 and therefore the output of the memory provides an indication for port 8 which is transferred to port address buffer 606 in the manner already described. The indication "Search for 0" in the M and P fields indicates that port 8 is the calling port. since a 0 has been written into connector 8 of PAM memory 513 during instruction 5.

After this function has been carried out by the PAM memory 513, the program goes to instruction 12 welter, which is a Z) £ C command. With this command the comparison output of the PAM spelcher 513 is used to determine whether a successful content-dependent Search while command 11 was performed or not. For the call connection described, the comparison panel is connected to the lower input of the

Gate circuit 526 created and from there via the Comparison bus line 512 led to the lower input of the! Comparator 409 to within the program indicate that a match has been found. If no match is found this represents a fault condition and the program goes to word 14 welter which is an alarm condition of the plant. The rest of the alarm function is not shown here for understanding its details are not necessary for an understanding of the invention.

Assume that there is a match is obtained, and in this case the program proceeds to word 13 by lowering the P-counter 403 Control of a Z4 signal is switched by one step. The command 13, which is a Z> 7W command, outputs the output of PAM memory 513 to port address buffer 606. At this point the port address buffer then receives an 8 indicating that port 8 is assigned to frame 2 Is. The program then goes to instruction 15, which the state of the connection 8 with the help of the mount selector 610 determined. If the connection 8 is found to be attached, this represents a disconnection condition and then a status word "Separate" becomes In inscribed the SAM spelcher 507. Those sections of the memory that are assigned to port 8 are returned to the initial state on the next occurrence of frame 2. Of the On-hook status of connection 8 indicates at this point in time that the previously determined off-hook status there was no valid operating request, but either a short-term fork switch button, a bolt of lightning or some sort of interfering signal.

If, on the other hand, it is established at this point of the tent, that the connection 8 is unhooked, this state is interpreted as a valid operating request. The interface is then controlled by a subroutine which will cause a search for a free outgoing registry.

The program memory advances under the control of the P counter 403 and the clock 415 of instruction Order welter. The P counter 403 determines the next one Address or the next command to which the program should go. The speed with which the program continues from instruction to instruction is determined by the clock. This is sufficient slowly, so that enough time is available for the work associated with each command.

Flg. 11 shows In in the form of a flow chart cells 1 to 9 of Flg. 10 specified subroutine "Free". Flg. 12 shows as a Tell flow diagram that "Register request" subroutine according to cells 11 to 15 in Flg. 10. It is believed that for the Flg. 11 and 12 no detailed explanations are required since the same operations have already been described in connection with FIG are.

Description of the PAM spelcher 513

Flg. 13 shows the details of the circuit elements, which form the PAM spelcher 513. The functions of this memory have already been described. Therefore, this section of the description is limited to an explanation of the various elements which make up the PAM spelcher.

The filling flop 1301 and the blocking circuits 1303

can be common JK flip-flops. The CAM Spelcher element 1304 Mnn a content-dependent addressable Memory Be in the form of an integrated circuit. the Drivers 1305 can be formed from integrated open-collector NAND gates. The decoder 1306 can be implemented as an integrated circuit. The lock section of the driver lock circuits 1307 can also be formed from integrated circuits. The same applies to the driver section of the circuit arrangement 1307. The Codlerer 1308 is formed from integrated circuits and is a so-called Prlorltäts Codlerer. The sense amplifiers 1309 are integrated circuits of the type RCA CD4009, specifically so-called complementary MOS inverters. The return tents pelcher 1310 is also an integrated circuit.

The operation of the PAM spinner 513 is first described in connection with a content-dependent search operation. The arrival of a / 8-search signal represents the Rw Filpfiop i3vi back and causes the output of flip-flop goes low.

The information stored in the CAM field of the program memory 404 is transmitted via the line F under the control of a signal from the gate circuit 1302 In

»The blocking circuits 1303 led. The CAM memory 1304 is currently receiving a voltage L at its query / write input. This L signal causes the memory to perform a port lookup operation based on the information provided by the drivers 1305 and the Trelbem / Lock

M circuits 1307 to perform. The CAM memory 1304 gives its output to the sensing amplifiers 1309-, which in turn lead the signal to the encoder 1308. The Codlerer is a Prlorltäts Codlerer. the Outputs of sense amplifiers 1309-0 to 1309 are π

J5 individually connected to the corresponding inputs of the encoder. The encoder input 0 is considered to be the lowest priority input. The input η has the highest priority. If the input 0 is the only active input, the encoder generates the binary code 0 at its output, which is connected to the gate circuit 519 In Flg. 5 communicates. It also generates a compare indicator signal that goes to gate 526. If both the input 0 and the input 3 are as active simultaneously, the Codlerer produces at its output a binary 3. If any input of the encoder active 1st, the comparison display signal is always on H. The Return-Zeitlagenspelcher 1310 If during the search operation is not in Task.

The CAM-Spetcher 1304 is addressable depending on the content. This memory can perform 4 functions: search, write, masked search, and masked write. It is an essential feature of this memory that a search or write operation can only be carried out for certain selected bits, the other bits not responding. One speaks of a masked search or a masked letter for the BiU that have not been influenced.
In the integrated circuits TMS 4000, which form the CAM memory 1304, two information bits are actually stored for each information bit used by the system. These two bits determine whether the operation required on the interrogation / scrolling path is carried out with regard to the particular Bltab cut concerned. For the P and M sections of the CAM memory, the P and M information from the program memory directly define these two input bits for each bit section of the relevant

fenden field. The two bits of information from the blocking circuits 1303 (5: η drivers 1305 supplied. There are two informailonsblts Present in the blocking circuits 1303 since the entire speaking tent layer is treated as one field.

Next is a write operation of the CAM memory Described in 1304. When the / 7 signal is set to H goes, the RW-Fllpflop 1301 is set and brings its output to H. Then the CAM field of the program memory 404 into the lock circuits 1303 out and the M and P fields are In the Trelber / lock circuits 1307 Transfer. The decoder 1306 is actuated at this point in time and accordingly the following explanation is about the gate circuit 1311 In den RQckkehr-Zeltlagenspelcher 1310 is enrolled.

There are three considerations involved in writing to CAM memory 1304. The first is that the sense / write input to H must be. The second consideration is that the match line (leading to the Abfohlverstärkern) of the connection word to the CAM memory is to be written into that must be maintained at L. This is accomplished by decoder 1306 which decodes the information on port address collection line 609. Note that the / 7 step signal controls the operation of the decoder 1306. Thirdly, the frame, P and M information which are fed to the data inputs of the CAM memory 1304 by the drivers 1305 and the driver / lock circuits 1307 determine whether or not the speech timing, P and M fields are being written into a masked write operation is to be performed. The masked write operation is identical to the masked search operation already described. During the write operation, the output signals of the encoder 1308 are of no importance.

the following describes the return time function. If the highest bit of the CAM field is a 1 during a step operation, a write signal is generated via the gate circuit 1311 and sent to the return timing memory 1310. The output of the gate circuit 1311 is connected to the write input of all integrated circuits SN7489, which form the return tent location spelcher. This input is the Schrelbbetätlgungselngang and has the effect that the information present at the data inputs is written into the address word. The address word for the return timing memory is supplied by the port address bus 609 and the data to be written comes from the timing address bus 517. If the return timing memory is not written, it continuously performs a read operation. The word to be read corresponds to the address information on the port address bus. The information read is given to the output bus and then to the gate circuit 521. The gate 533 is an OR gate, whose output is at H when a 1 in the output data from the return time-slot Spelcher ^ω is present. The output of the OR gate 533 is connected to the gate circuit 523.

The PAM memory field labeled "return time slot" is used for call forwarding or consultation calls used. For explanation, it is assumed that the terminal 8 is initially through the Time slot 2 is served. In this case there is a 2 in that Speech allocation field of the PAM memory written. Terminal 8 then emits a hook switch signal to initiate call diversion. Then the system assigns a new connection to port 8 Tent position too. It is assumed that this is tent position 5. There is then a 5 in the talk time lag: nfcld des Connection 8 and a 2 in the Rückkihr-Zeltlageabschnltt of the word for port 8. This 2 is used below to create the original To operate the call connection when the transfers are finished.

Explanation of further components of the system

The SAM spelcher 507 can consist of integrated 4x4 memory arrays exist. Such integrated circuits have separate addresses for writing uno Read and enable simultaneous writing and reading. In addition, some integrated circuits are used used to set the higher-order bits for both the reading ais also to decode the write addresses. These integrated circuits are four-line on sixteen-cell decoders.

The BIM memory 510 and the TAM memory 626 are made up of integrated circuits, the 16x4 Spelcher arrays represent. In addition, an integrated circuit is used to generate the highest digits Bits of the address to be decoded and the correct one Operate integrated circuit in BIM memory. the Integrated circuits of the memory only decode the four lowest-order bits of the address. The additional integrated circuit can be a dual, two-cell to four-cell decoder.

The SOM spelcher 531 and the HAM spelcher 607 are made up of standard, insertable Dloden matrices.

The attachment selector 610 uses integrated circuits to perform the multiplex transmission of the monitor status information from the line switches to the gate circuit 613. In addition, an integrated circuit can be used to select the integrated circuit that is to be active. In other words, an integrated type Circuits decodes the highest position :: bits of the port address and another type of integrated Circuitry decodes the lowest bits of the address.

Ringing circuit 628 includes a decoder and a one-shot circuit for each line switch. The decoder uses built-in Circuits representing four line to sixteen cell decoders. The monostable circuits are also integrated circuits, each containing two monostable circuits. When actuated through the decoder, the monostable circuits generate a pulse with a duration of 5 ms. That Ringing current start signal / 10 is fed to the actuation input of the integrated circuits.

The memory 624 is composed of NAND gates with an open collector, which are connected together to form a manifold arrangement with an open collector. The signals GA, GS and G € excite groups of these NAND gates in order to generate a bit pattern which is then applied to the gate circuit 623.

The multiplexer 620 is composed of integrated circuits, the four-way two-line to one-line data selectors are.

The counters 602 (PAC), 502 (SC) and 504 (FC) also consist of integrated circuits.

The frame address buffer 615 and the port address buffer 606 are formed from integrated circuits that are quadruple D controllers.

Explanation of the PIP Spetcher 601 - Flg. 14th

Flg. 14 shows the details of components 601, 617 and 620 in FIG. 6. The main element of the PIP memory 601 is the CAM memory assembly 1401. This component is composed of integrated circuits of the Slgnetic 8220 type, which are high speed content addressable memories. The (not shown) 1st to the inputs AO and Al search Elngang des.CAM memory and connected (not shown) of the Schrelbelngang with the WO and WI-inputs of the integrated circuits.

The CAM memory 1401 can be addressed selectively with any access as well as content-dependent. The compare output lines 1404- are at Z, unless they are posted to H to indicate a match. For example, during a search operation the content-dependent Verglelchs output line 1404-4 on L, when the tent layer number in word 4 of the memory for the terminal 4 not to the upper input lines 1405- incoming tent upper layer number coincides. The conduit Accordingly, when a match occurs, 1404-4 be H to indicate that the incoming time slot number in the word 4 1st stored associated with the terminal. 4

The multiplexer 1406 may consist of integrated circuits that are four-way, two-to-one, data selectors. Whenever the selection input of the multiplexer is H , the B input signals are multiplexed from the all-zero circuit 616 to lines 1405-0 to 1405-n. If the dial input is L , the A inputs, which receive the tent location number information, are multiplexed to the 1405 lines.

The drivers 1405 can be made up of integrated circuits exist.

The decoders 1408 can also be integrated circuits. Some of these integrated circuits decode the information on port address bus 609. Other integrated circuits, which are two-input, open-collector NAND gates, each have one input connected to an output of the first circuits and the other Input Is connected to the actuation output 1409 of the decoding. When a terminal 4 on the address bus is provided to the address terminal 4 display, so if the output 1410-4 of the Decodleres 1408. H and all other outputs 1410- are low, provided that the Betatlgungselngang is H 1409th

The one-shot circuit 1411 may be an integrated one Be circuit.

The circuit arrangement in Flg. 14 leads both optional write and content-dependent search operations. First, the write operation will be described. Each word in CAM 1401 is a time multiplex connection assigned. If a connection is active in a tent location, that includes the connection The word assigned in the CAM memory 1401 is the number of the tent location. If the connection is not active, so the word assigned to the connection in the memory CAM contains a 0. It is assumed that a 2, the represents the tent layer 2. In the word for connection 4 is to be registered. In this case, the system processes this call during the Frame 2 and port address 4 is on port address bus 609.

The start PIP signal / 1 is generated and effects the presetting of the flip-flop 1412. As a result, the output S of the flip-flop goes to H. If the tent position number 2 matches the frame number 2, ίο the D signal of the timing logic circuit 505 brought to H. The output of the AND gate 1413 is now at H, so that the output of the NOR gate 1415 goes low and causes the output of inverter 1416 at H. The Ausgangssigna] of the inverter 1416 is actuated to the decoder 1408. When the terminal 4 on the address bus 1st, all the match lines of the CAM memory 1404 with the exception of the output line are maintained by the decoder on L 1404-4. The search input of the CAM memory 1401 is at H and the write input is at L. The V / Shie input of the multiplexer 1486 causes the tent location number 2 to be passed from the A input to the input line 1405-2. When the ZelUagennummer 2 at 1405-2-Elngang Hegt and all Verglelchs-2S are apart from the line 1404-4 output lines held by the decoder to L, the tent position number 2 is in the word 4 enrolled the CAM memory 1,401th The flip flop 1412 is reset on the negative flank of the D signal at time TL (flg.9).

When port 4 becomes free, a 0 is written to word 4 of memory 1401. At this point in time there is a 4 on the connection address bus and the stop PIP signal / 8 is generated. This signal causes multiplexer 1406 to connect inputs B, which are all 0, to the output of the multiplexer. The stop PIP signal at the gate circuit 1415 generates the same signals as described in the previous paragraph and causes a 0 to be written into word 4 under the control of the decoder .1408.

14 shows that when the Stop-PIP or Start-PIP signals are not present, the CAM memory 1401 is in the search mode. The search begins when the multiplexer 1406 receives the tent location number. The search input is then L and the scrolling gear is H. The decoder 1408 is also switched off. The CAM memory then searches continuously on the basis of the 5-digit, which represents the tent location number, which serves the call connection whose line switch is to be closed. The comparison lines 1404-0 to 1404 - /> are connected to the drivers 1407. It is assumed that word 4 of the CAM memory contains the tent position number 2 and that the time slot number 2 now arrives at the S input. In this case, within 30 to 40 ns after the tent point Π In Flg. 2 brought the comparison line 1404-4 on H. The monostable circuit 1411 generates an output pulse which, however, actuates the * ° gate circuit 1417, the driver 1407. The left input of the gate circuit 1417 is affected at this point in time by the gate circuit 1411, which inverts the signal L from the gate circuit 1416. DcrTrclberausgang 621-4 is brought to L and the other ^ driver outputs remain at H. Thus, the circuit breaker 4 is closed at this time and connected to the Zeltmultlplex-Sammelleltung. The length of the output pulse of the monostable

Circuit 1411 is equal to the time span in which the Line circuits must be operated and connected to the manifold. This time is shorter than a microsecond to provide a suitable protective space provide.

Description of the tone generator - Flg. 15th

Flg. 15 shows the details of the tone generator 618 in FIG. It has already been described like that Tent position payer 502 one step every microsecond weltergeschältet and how the output signal of the Payer as time slot information to the left entrance of the SAM memory 507 is applied. Besides is it has been described that the memory 507 has a word location for each position of the counter and consequently for each Owns tent location. The content of each word passage gives that the current state of a call masking operated by the system, that of the corresponding one Time slot is assigned. It has also been described that the supply of a timing number to the left input of the SAM memory through the counter 502 causes the memory to display the moment read out the stored status word assigned to the time slot number and transfer it to the bus 508-4 to give. The tent position counter switches once Each microsecond continues, the time slot number arriving at the SAM memory changes once each time Microsecond and the memory gives ah the manifold 508/4 a status word that shows the status for the represents the respective tent pitch number.

The status word on bus 508/1 is sent to the upper input via bus 508C of the tone generator 618, which decodes each incoming word to determine whether the word generated by the Word reproduced state requires that a tone be put on the tent multiplex collection line. Of the Generator generates any sound that may be required and emits it from one during the tent ply tent Microsecond to time division multiplexing.

According to Flg. 15 the tone generator contains a decoder 1503, multiple sound sources 1501-0 to 1501-3, a multiplexer 1502, a line switch 1505 and a logic circuit 1504. The four sound sources 1505-0 to 1501-3 in normal private branch exchanges the TOne for calling, quick calling, busy and generating elections. Multiplexer 1502 includes five operational amplifiers 1502/4 to 1502E, the commercially available types could be. The decoder 1504 can be an integrated one Circuit SN7442, i.e. a 4-to-10 decoder. Logic circuit 1504 may include TTL NAND gels and -Inverter included.

The decoder 1503 and logic circuit 1504 decode any tent ply status word arriving over bus 508C. The state words that the four sound sources select differ only in the last two bits. The decoder 1503 decodes the last two bits. Logic circuit 1504 decodes the most significant bits of the status words. The outputs of the logic circuit 1504 are high when a status word is present that requires the creation of an operating tone. If the outputs of the logic circuit are on H 1504 an output energizes the decoder 1503. The other output line causes the switch 1505 to connect the operational amplifier 1502 £ the Zeltmultlplex-Sammelleltung 619th

If the last two bits are a 1, that is Decodlererleitung 1503-1 to L. This is the Operational amplifier 1502Ö operated, which then the Output of the Tonquetle 1501-1 to the input of the

• Operational amplifier 1502 £ switches on. This amplifier then sends the signal to the line switch 1505, which sends the signal to the tent multiplex Sarrimeileltung brings. The three other op amps that provide information received from the other phone sources are switched off because their decoder output signals are on

ίο // lie.

As can be seen from the above explanation, the decoder 1503 and the multiplexer 1502 act as data selectors work. On the basis of the two lowest-digit bits of the status word, the data

is to select the correct tone and switch it to the Line switch input 1505 ah. As already mentioned, the on-off status of this line switch is set by the highest-order bits of the status word controlled by the logic circuit 1504 will.

The main advantage of controlling a tone generator with a system status word is that that the system does not under any circumstances carry out any additional work has to enter a tone in a time slot or to remove it from a tent slot. Instead it will this work is done automatically by the tone generator when the Zeltiagen state words arrive and be decoded. With such an arrangement, a sound cannot be erroneous at a time slot given, for example during his speech state. In addition, there is no need to perform any eavesdropping operations to determine which TOne during which tent position are supplied. This funk tion is carried out automatically by the tone generator.

Regarding the components, the need for a separate storage system for controlling the creation and separation of operating tones to and from the time multiplex collecting line avoided during selected tent locations. Such a storage system requires in known systems usually one word for each tent location.

In addition 12 sheets of drawings

Claims (4)

Patent claims: 1. Method for controlling a spelcher-program-controlled tent multiplex ^ telecommunication system, in particular telephone switching system, in which the subscriber circuit (312) is scanned in appropriate tent intervals for connection requests addressed, in which the subscriber circuits with which a connection request is present have a free tent location within is assigned to a frame having a certain number of time slots and the connectedness after the connection is dependent on selection information of the subscriber circuits to a manifold (TDB): s are the and in which a programmable logic controller (304) 1st provided for controlling the switching precedent, characterized characterized in that a special M frame is provided for each tent location assigned to an active subscriber circuit and that processing operations, including connection operations, are carried out for this tent location every time this particular frame occurs. 2. The method according to claim 1, characterized in that a special frame is provided for each free time slots for carrying out general control processes, for example for scanning the free-busy state of subscriber circuits (312). ,. ^w 3. Spelchsrprogrammgesteuerte time division multiplex switching system for performing the method according to claim t or 1, characterized in that the spclcherpiogrammierte control (304) during the occurrence, ädes frame generates a «status word that a memory (313) is provided, which the tent position a specific connection of the subscriber circuit (312) assigns this connection and generates output signals which identify each switch (311) that is currently active when the assigned tent location occurs in each subscriber circuit (312) and that a circuit (316) in response to the output signals of the memory (313 ) and on the status word each switch (311) connects to the bus line (TDB ) during the occurrence of the assigned time slot, so that the subscriber circuit (312) is connected to the bus line via the switch (311). 4. Memory program-controlled tent multiplex · switching system according to claim 3, characterized in that a tone generator (328) gives a tone signal given by the special status word during the tent position on the collecting line (TDB) due to a special status word during a tent position and thus also to the Bus connected subscriber circuit (312) supplies a special tone signal. 60