DE1112999B - Circuit arrangement for restoring coded information, preferably telex characters, in telecommunication, in particular telex switching systems - Google Patents

Description

Circuit arrangement for restoring coded information, preferably of telex characters, in telecommunications, in particular telex switching systems The invention relates to a circuit arrangement for restoring. of coded Information, such as telex characters, in more than one memory is used.

An arrangement for the implementation of information in which only a single Storage device is used, such as a magnetic drum, can use clock pulses in a known manner, which are supplied by the memory itself and which control the other parts of the system. For this purpose, for example a special track specially prepared for this is provided on the magnetic drum will. There are no small fluctuations in the speed of rotation of the drum Significance because these fluctuations for all parts at the same time and to the same extent be effective.

In systems in which two different storage drums or even storage of various types, such as magnetic drum on the one hand and magnetic tape or wire on the other, work together, there is a risk of falling out of step, as the extraordinary high demands on the accuracy of the circulation or feed speed of the various stores are very difficult to meet.

It is now known to counter this difficulty in that a buffer memory is provided to accommodate a large block of messages can and to which the information is fed after a certain time cycle and after a second, different time intervals. Such an arrangement however, requires a considerable amount of resources, especially if the scope of the message to be transmitted as a whole requires thousands of binary elements.

It is now intended for such a known arrangement of a buffer memory between two message memories, of which the receiving memory is a small one should run faster than the donor, the disadvantage of excessive effort be eliminated according to the invention in that the rotational speed of the Information receiving memory is only slightly higher than that of the information emitting memory that the storage capacity of the intermediate memory is the size of a few bits, for example in one for storing only one telex character sufficient extent and that a comparison device is provided, which controls the time of the transfer.

Through these measures, it is possible to restore the one memory in the other with the very little effort of a message cache can be made executable with only a few bits of storage capacity and yet on a strict one To be able to do without maintaining the synchronism of the two memories.

The invention is explained in more detail using an exemplary embodiment in which such an arrangement is used in a memory system in which each message unit (e.g. each letter) requires five memory elements and a further, unused memory element is provided in each case. In the drawings, find the necessary for a better understanding of the embodiment schematic drawings, in FIG. 1, an overview circuit diagram for the entire control processes by leading switching device of the arrangement, hereinafter referred to as "logic circuit", and in FIG. 2, a time-slot overview.

In the arrangement described here, the information recorded is entered into a buffer memory suitable for receiving message units consisting of five steps; this process is controlled by a six-stage counter, which in turn is indexed by the clock pulses of the inputting memory, for example a magnetic tape. The information is now -weiterzugebende this buffer memory - removed, but this Ausspeicherungsvorgang is controlled by a second six-step part of the scale, but which is incremented by the clock pulses of the receiving memory, for example a magnetic drum. Of course, it happens from time to time that the buffer memory no longer contains enough information to enable the reading of a complete message unit. There - that's why a switching element is provided, which recognizes this fact in order to prevent in this case that is started with the transmission of an unavailable time expectant message unit at all. There are therefore positions on the drum for message units in which nothing is stored.

These empty positions can be identified by the respectively sixth storage element not used for information recording as one of the relevant message unit associated step of a circulating distributor is used to indicate whether the next position is occupied or not.

It should be pointed out at this point that the message memory on the receiving side must have a somewhat larger message capacity than the transmitting side in order to make these unused positions for message units possible at all. For the storage of the information as a sequence of message units, i. H. Unit by unit, it is unimportant whether the individual message units are in consecutive memory positions; rather, it is sufficient to display the sequence of these units in a distributor.

An arrangement similar to the one described above is shown in detail in British patent specification 762 094, where the speed ratio of the telegraph speed to the limit frequency of the drum is 1: 1000, namely 50 baud to 50 klU. The received letters are converted one by one in a buffer memory from the temporal sequence into a juxtaposition of their elements and, during the pause between two letters, are written in a position marked in a certain drum track; in this case, the drum remains unused for a large number of revolutions during the reception of a letter. In this case, the difference in speed is so great that the problem dealt with in the present description does not arise at all and the buffer memory can always be stored full before a withdrawal is initiated.

Moreover, in this known arrangement, there is an intermediate termination the storage process and the need to restart it for the following Letters relatively so much time available that the correct drum position waited for the storage of the letter just saved without further ado can be. In this way, the letters intended for recording can be used Positions around it are occupied one after the other.

In the case of the invention, the situation is almost exactly the opposite. As required, the two memories have approximately the same speed. The reaction takes place virtually without interruption place, interrupted only now and then to the full storage to end a letter in the slower moving storage, resulting in the occasional appearance of gaps in the track of the faster moving drum memory that JE hereof but otherwise in direct chronological succession, letter after letter, is recorded all around on its storage track. In the subsequent transmission of the information from the drum track to the further line, these gaps are meaningless due to the extraordinary speed reduction, and the processes take place in the same way as is the case with the known arrangement discussed above.

The invention is thus mainly concerned with a problem which occurs in exchanges, generally in those in telex networks, in which transmission links intended for nodal offices and acting at high speed cooperate in different ways.

Referring to FIG. 1, an embodiment will now of the invention are described below. It is assumed that information recorded in a first memory is to be transferred to a second memory. The first memory is represented by the tracks 11TR of the magnetic tape IIT, the second memory by the tracks 12DT of the magazine drum 12D. In addition to the information recorded in the track IIT, which is specifically used for recording messages, a special clock track 11CT runs, with whose clock the clock of the message steps coincides; the drum 12D for its part carries a clock track 12CT permanently impressed on it, from which all control processes related to the drum are derived. The read heads 11RA and 11 P are used to read the information or the clock tracks of the magnetic tape, while 12P and 12 W serve both as read and write heads for the clock and information tracks. The rectangular characters identified by 11RA, 11P, 12P and 12W may, in addition to the relevant reading or Write heads each represent an associated amplifier. 11C denotes a six-stage counter that is switched on by the pulses taken from the clock track 11 CT, which in turn emits counter pulses 11 c 1 to 11 c 6 (Fig. 2) that are offset in time in an uninterrupted succession, the immediately successive rows (cycles) of six pulses form; that of the clock track Lict taken llp pulses (Fig. 2) are only very briefly at the end of each count 11 c 1 to 11 c 6 effective.

The control pulses Ilra obtained from the stored information via the read head and amplifier 11RA, in cooperation with one of the counting pulses supplied by the counting element 11C , control a series of gates via which the toggle circuit 11F to 15F in the event of a coincidence in its working position 1 to be brought. The gates are shown as circles; the numbers entered in these indicate the number of impulses whose coincidence opens the gate. This process by which the recorded, information is transmitted to the flip-flops, continues without interruption, wherein the control operations are not indicated in Fig. 1 for the flip-flops 12 F, 13 F, 14 F correspond to those of 11F and 15F, mutatis mutandis, in such a way that the Impulsellcl, 11c2 and 11c3 are to be used accordingly with regard to the counting pulses coming from the counter 11C.

With 12C a likewise six-stage counter element is designated, which is advanced by the clock pulses 12p supplied to the clock track 12CT of the receiving memory 12D ; the pulses 12 c 1 to 12 c 6 supplied by this counter also act via a series of gates on the flip-flops 11 F to 15 F in such a way that they flip back to their starting position after the reading process when the other coincidence conditions are present.

The pulses 12p also serve to - generate the pulses 13 p and 14 p; These two pulses experience a delay of 0.25 and 0.75 of the period of the pulses 12p by delay elements 11V and 12 V. Their pulse duration is about 51) le the duration of a full cycle of the pulses 12 p. The delay element 12 Y is temporarily short-circuited to the p 13 and p pulses to let occur simultaneously with the pulses 12p fourteenth

If the tilting element 18 F is in normal operation, in its working position 1 and thereby emits a pulse 18f 1, the outputs of the flip-flops 11F to 15F during the pulses 14p by the Zählimpulse12c6, 12c1 to 12c4 are sequentially sampled by and to the input Amplifier 12 W 'of the write head arrangement 12 W of the drum store switched through.

The fact that the sequence of the ordinal numbers of the pulse sequence 11 c appears to be shifted compared to the sequence of the conversion processes is due to the fact that a special main control pulse technique is used to control the gates via which the flip-flops 11 F to 15 F are influenced, as is the case with them , has already been described in German patent application 113000 IX / 42m. The output of a gate is unlocked at the end of the control pulse coincidence periods. Thus, the tilting element 11F is tilted to its working position 1 already at the end of timing pulse 11 c 6, and it then remains during the entire duration of the following time pulse 11 c 1 in this position. This principle, which presupposes a slight overlap of the ends of the time slots of the Takti, mpulse with the beginnings of the information elements, is applied to all gates, and it must be taken into account when considering the mutual time slot relationships according to FIG.

The flip-flops 16 F to 19 F take over the control of the processes associated with the execution of an entire cycle (= one-time passage through the six stages of the counter 11 C) . The flip-flop 16F stores a control character in the sixth time slot preceding each group of five message elements that are converted; the time is in each case determined by the flip-flop 17F, in the memory 12 the memory C obsolete 11 C; the flip-flop 18 F determines whether or not the following character is to be passed to the write head amplifier 12 W; the flip-flop 19F eventually directly subsequent to an overtaking maneuver prevents the flip flop 17 F undesirable recovery operations.

During normal rounds of Zählgliedes 11C 'is tilted at the end of the count KippschaltungI7F 11c4 in their working position 1 and by the delayed Zeittaktimpuls13p during the count 12 c 5 back into its rest position 0th The toggle circuit 16F can toggle to its position 1 at the end of the counting pulse 11c5 and cause a pulse 16 f 1 if the toggle circuit 17F is still in its working position 1 at this point in time and emits a pulse 17f 1. The counting element 12C , however, constantly strives to catch up with the counting element 11C , and always shortly before this occurs, the flip-flop 17F is returned to its rest position 0 before the flip-flop 16 F can emit the pulse 16 f 1. When the pulse 16f1 occurs, the flip-flop 18F also emits a pulse 18f 1 at the end of the counting pulse 12c5 in its working position 1 ; in the other case the flip-flop 18 F remains in its rest position 0, and a pulse 19f1 occurs on the flip-flop 19F the next time the counter 12C rotates. During the pulse duration of 19f1, the toggle circuit 17F, which is brought back into its working position 1 by the counting pulse 11c4, has no possibility of returning to its rest position, and as a result, the toggle circuit 16F is periodically switched between its two positions 1 by the counting pulses 11e5 and 12c5 and 0 tilted back and forth; the flip-flop 18F goes to its working position 1 on the basis of the first pulse 16f 1 and remains there. During this time, a number of message elements from the buffer memory 11F to 15F corresponding to the revolutions of the counter 12C over the write head 12 W 'on the drum memory 12D up to the moment when the counter 12C has caught up with the counter 11C so far that the counter , npulse 11 c 4 and coincide 12E3. This coincidence brings the flip-flop 19F back into its rest position 0 and prepares the flip-back of the flip-flop 17F , which is triggered by the counting pulse 12 c 5 . Every time the counting pulse 12 c 5 occurs, the flip-flop 17 F flips back to its rest position 0 , and this will occasionally occur before the flip-flop 16 F has time to go into its working position 1. As soon as this occurs, the toggle circuit 18F is brought into its rest position- 0 , the control potential 18f 1 disappears, and during the following cycle of the counter 12 C there is no transmission from the buffer memory 11 F to 15 F via the write head 12W to the drum memory 12D . During this circulation, the flip-flop is, however, brought by the pulse 12c3 in their working position 1 and characterized so long prevents too rapid tilting back the flip-flop 17F and therefore a restoration of the withdrawal from the buffer memory until the re-coincidence of the pulses 11 c4 and 12 c 3 , the resetting of the flip-flop 19 F causes. There is then no direct way that the flip-flop 17 F is reset before 16F again tilts In this way, the withdrawal from the buffer memory is actually interrupted only for a round of Zählgliedes 12C.

It can be seen from Fig. 1 that the flip-flop 19F also controls the delay in the formation of the pulses 14p. If the trigger circuit I9F is in its rest position, two delay elements 11V and 12V are effective due to the control potential 19f0, while the control potential 19 f 1 corresponding to the operating position of the trigger circuit 19F by short-circuiting the delay element 12 Y causes only the delay element 11V to be effective and the pulses 14p and 13p coincide. This change in the mutual time slots has the purpose of achieving a wide margin between the flip-flop and flip-back times of the flip-flop circuits 11F to 15F; As already said above, the delay element 11 V brings a delay of about a quarter, the delay element 12 Y one of about half the repetition period of the pulses 12p.

Fig. 2 shows the timing chart. The pulses 11 p and the cyclical circulation of the counting pulses 11 c 1 to 11e6 emerge therefrom without further explanation. The time slots are chosen so that the toggle circuit 11F can toggle during the counting pulse 11c6, if necessary, before the end of the corresponding clock pulse llp. This applies mutatis mutandis to the other Kippschaltungen12F, 13F, 14F and 15F thus obtained for the possibility to tilt at the end of the pulse 11 c. 4 The flip-flop 17F is in accordance with the conditions set out above into position 1 when the count 11 c 4 is completed, and the flip-flop 1-6F has the opportunity to go to their working position 1 when the pulse 11 c 5 is over. The flip-flop 18F follows the flip-flop 16F.

There are three points in the schedule that need to be examined more closely. First, the point at which the counting member 12 C overtakes the counting member 11 C. The time curves labeled 1.2c5X and 13pX show in brief an example of an overtaking process in which the flip-flop 16F flips because the clock pulse 11 p arrives before the flip-flop 17 F flips back. In the by curves 12 c 5 Y, and the case shown 13pY requires the relatively larger spark advance Zählgliedes 12C that the Kippschaltung17F tilts back before the flip-flop 16F umschlägL Second, it must be ensured that the counting member properly 12 C, the withdrawal and the latest news element carried out before the overtaking process begins. The timing diagram shows how the pulses labeled 12c4Y and 14pY only coincide after the flip-flop 15F has been toggled. In the previous example (with the pulse 12 c 5 X) more time would have been available. Since the flip-flop 18 F has not flipped, no message element is stored, but it is necessary to ensure that the flip-flop 11 F has been read before the following message element arrives.

In order to pick out the worst case, it must be assumed that the speeds of the counting elements 11 C and 12 C are practically the same. It can be seen that the pulses 12 c 6 Y and 14 pY arrive in time to reset the flip-flop 11 F for the following message element. If the speed difference is greater, then the pulse 12c6 will occur earlier, as shown in FIG. 2 by 12c6Z; this then gives a greater leeway. It should also be noted that the pulse 14p, when the flip-flop 19F is in its working position, experiences a short rather than a long delay as a result of the control potential 19 f 1. However, this change in the time slot does not cause the write head amplifier to stop, which continues to receive information elements from the memory elements of the buffer memory and to send them to memory 12D with the next pulse 14p.

Finally, when using a buffer that can only hold one letter length, that is to say one message unit, precautions must be taken to ensure that the first letter is not lost when the storage is started. Whether a message unit (letter or character) is currently written in the drum track or whether it is a space depends on the mutual relationship between the two clock tracks on the tape or on the drum during the recording and storage of the previous message unit. This is why the first unit on the tape (letter, character) of a message to be converted cannot be used at all to initiate the relocation, since the relationship between the two clock tracks determines whether or not the second message unit on the tape can be relocated immediately must wait for the next storage position on the drum. It must therefore be provided that an additional and meaningless message unit is somehow written onto the tape as the first message unit, e.g. B. by doubling the first unit, by adding a false unit or simply a "blank character". The latter solution is preferable for operation. The additional unit must of course be written in the track of the tape memory together with its own clock track characters assigned to it, if it is not to lose its meaning.

Under certain conditions it may be desirable to provide more than a buffer memory in the manner of the memory 11 F to 15 F and the message to pass, unit by unit from memory to memory.

There are various ways of monitoring the positions which are intended to receive a communication unit but which have remained empty during the subsequent reading of the drum track. If the sixth memory element is used directly for this purpose, then it is necessary to know the start of the transmission in order to be able to make the display element available to the first message unit. This can be achieved by giving a start signal from the tape, which is used to control the toggle switch 17F and toggle it into its working position 1 . In addition, it is necessary that the start and end point of the message are made known to the distributor for the message units. If the information is stored unit by unit in accordance with the step-by-step forwarding, the distributor must check whether an information unit is stored in the following position or whether two steps must be taken. The end of the message can be identified by two consecutive empty positions for message units (letters).

It should also be noted that the unused, that is, remained empty Letter positions of the drum storage are expediently used for monitoring can be because, although the marking in the control of the track is the appropriate Marks the letter position as not belonging to the text, this marking itself is nonetheless read positively, so that their evaluation is at the same time may be used bringing in one supplied from a separate source to initiate monitoring information in the relevant position.

Of course, the application of the inventive concept is limited not on the storage types selected as an example in the arrangement described above, on the contrary, any other storage form can also be used for such Information conversion can be used, such as B. a ferrite core or a ferroelectric. Matrix, a cathode ray tube, acoustic or magnetostrictive delay or delay elements or memory with series or series-parallel storage. Also with the other special design options shown in the arrangement shown above of the invention, such as number, type and mutual interaction of additional, tax and monitoring devices, these are of course examples which do not exclude a different implementation.

Claims (2)

PATENT CLAIMS: 1. Circuit arrangement for restoring coded information, preferably telex characters, from one information memory to another information memory operated at a higher speed than the first-mentioned memory using an intermediate memory in telecommunications, in particular telex switching systems, characterized in that the speed of rotation of the Information receiving memory (track 12 DT on drum 12 D) is only slightly higher than that of the memory delivering the information (track 11 DT on tape 11 T) that the storage capacity of the intermediate memory (12C, 11F to 15 F, 16 f 1, 18 f 1) the size of a few bits, for example to an extent sufficient for the storage of only one telex character, and that a comparison device (17F) is provided which controls the time of the relocation. 2. Circuit arrangement according to spoke 1, characterized in that each of the two main memories (11 T, 12 D ) carries a time clock track (11 CT, 12 CT) impressed on it permanently. 3. Circuit arrangement according to claim 2, characterized in that each of the two main memories (11 T, 12 D) is assigned a cyclically incrementing counter element (11 C, 12 C) which is incremented by the clock track (11CT, 12CT) of the memory concerned and by means of counting pulses (11c1 to 11 c 6, 12 c 1 to 12 c 6) sent by it, the correct storage and retrieval of the elements of the individual information units (letters, characters, blank) in the buffer memory (11 F to 15 F) . 4. Circuit arrangement according to spoke 3, characterized in that a device (16 F to 19 F) is provided which comparatively monitors the progression of the two counting elements (11C, 12C) and the conversion of the information from the buffer memory (11 F to 16 F) to the receiving memory (12 D ) is delayed for one cycle of the counting element (12C) assigned to the receiving memory (12D). 5. Circuit arrangement according spoke 1, characterized in that the buffer memory (11 F to 15 F) comprises only the memory cells required for receiving a single information unit (letter, character, blank). 6. Circuit arrangement according to claim 1, characterized in that the buffer memory (11 F to 15 F) comprises a number of memory cells suitable for receiving more than one information unit. 7. Circuit arrangement according to claim 3, characterized in that the buffer memory (11 F to 15 F) from the pulses (11c1 to 11c6, 12c1 to 12c6) coming from the corresponding counting elements (11 C, 12 C) in each case correspondingly for the one - or withdrawal controlled tilting elements (11F to 15F). 8. Arrangement according to claim 4, characterized in that means (16F to 19F) are provided to in a respective group of memory cells (11 F to 15 F) assigned to the reception of an information unit (letter, character, blank) to control the later further transmission from the receiving memory (12D) serving information about whether or not an information unit has been recorded in the following memory cell group. 9. Circuit arrangement according to claim 8, characterized in that the receiving memory (12D) is assigned an allocation device (17F) through which the information about the occupancy status of the individual memory cell groups is scanned and evaluated to achieve continuous forwarding of the information. 10. A circuit arrangement according to claim 4, characterized in that the comparative monitoring is carried out in that at the time of a certain clock pulse of the counting element (11C) assigned to the outputting memory ( 11T) it is determined whether this pulse is compared to the corresponding pulse of the counting order the counting element (12 C) assigned to the receiving memory (12D) leads or lags behind. 11. Circuit arrangement according to claim 10, characterized in that in the case of an advance of the second-mentioned pulse compared to the first-mentioned, the conversion from the buffer memory (11 F to 15 n to the receiving memory (12 D) is interrupted and the comparison device (18 F) is in the the interrupt-causing switching position is held is completed by the overtaking. 12. circuit arrangement according to one of claims 1 to 11, characterized in that the due to the overtaking store for the message itself unused remaining sub- the receiving Trömmel (12D) for receiving Publications taken into consideration: German Auslegeschrift No. 1031827; "Telegraphen-, Fernsprech- und Funktechnik", 25th year, 1936, issue 4 (special print No. SH 6513-12 from Siemens & Halske AG. ).