DE3040209C2 - Process for the cyclical transmission of still images combined to form magazines in time division multiplex operation - Google Patents

Description

The invention relates to a method for the cyclical sending out of magazines combined Information pages in which the data values of several magazines are combined into a time division multiplex signal will.

Various information distribution systems are known in which the participants receive a cyclical all-round information is available. The participant looks for him from this offer interesting part out. In the current systems, the subscriber is generally only responsible Data channel with low transmission capacity available.

In the future expansion of information systems, thought is also given to broadband channels, e.g. B. Video channels to be used as transmission routes. A large number of Subchannels are formed. These extended systems are known as cable text systems. she can with regard to the selection and presentation of the information at the participant with the known Teletext systems are compared, but offer a much larger volume of information.

A teletext system is in volume 4 of the telecommunications report. Pages 126-132, editor: Federal Ministry for Post and Telecommunications, Sales: Dr. Heinz Eger, Goethestr. 56, bathroom Godesberg 1, described. In this process, the channels that are not used for television image transmission are used Lines of television signal transmit pages of text and graphics. The information offer is on some 100 Pages limited, otherwise there would be no longer reasonable waiting times to find the one you want Information page must be accepted.

In the book "Electronic Text Communication", editor Prof. W. Kaiser, Springer-Verlag, 1978, is a cable text procedure is described in the essay "Kabeltext" (pages 69-84). With regard to the presentation of information for the subscriber, this procedure is similar to teletext. To be transferred however, not individual lines of a video signal, but a complete video or other broadband channel used. Accordingly, the volume of information that can be offered by cable text is large much larger. It can contain more than 10,000 pages of information organized in a variety of magazines are. An information page is understood here to be the amount of information that is contained in a one-off Access can be displayed on the screen of a display device. The page format of the above telecommunication systems corresponds to the representation of 24 lines with 40 characters each. Other formats are also possible.

A magazine brings together pages belonging to the same subject area and accordingly contains the Representations in the book "Electronic Text Communication" up to about 100 pages. For the cyclical Teletext broadcasting is an appropriate feature in a number of articles in trade magazines described. Please refer to the article »System for editing and displaying subtitles the English Teletext Standard, Rundfunktechnische Mitteilungen, 1978, Issue 1, pages 1-9.

The devices described save the information volume to be sent cyclically on one magnetic disk. This is generally magnetic disk storage or tape. Next to the cyclical sending of information are also administrative functions such as deleting, exchanging, Insertion and modification of pages possible. The functional sequence is controlled by a small computer controlled. The managed information volume is a few hundred pages that is sent out Data stream limited to around 250 kbit / s. It is therefore only possible to set up a few magazines. One

substantial increase in transmission capacity fails due to internal processing and access sides.

In a planned system, the circulating

3 «Information volume in the order of magnitude of approx. 10,000 pages lie and be arranged in approx. 100 or more magazines, with a serial data stream of approx. 10 Mbit / s results. This places very high demands on the processing

-5 speed set.

It is necessary to first explain the organization of the transmitted data stream.

The already mentioned structure of the information offer in magazines is expedient This is reflected in a division of the broadband transmission channel into a large number of sub-channels, Each magazine is assigned its own sub-channel. The time division multiplex method is particularly suitable for this.

Fig. 1 shows the organization of a total of 104 sub-channels, as used by Prof. Kaiser for a cable text system. 100 useful channels NK 1 to NK 100 - corresponding to 100 magazines has been proposed. The transmission speed in the individual subchannels is 64 kbit / s and thus corresponds to a standardized transmission speed of digital transmission channels. 1 data word of a magazine is transmitted in each of the 100 useful channels NK 1 to NK 100. The useful channels NK 1 - NK 100 are preceded by a synchronization part SYT comprising 3 subchannels. A backup byte PB fills a further subchannel in the multiplex time frame MUR.

From this organization of the multiplex time frame it can be seen that those in the total data stream are in time consecutive bytes always belong to different magazines. A direct reading of the Data words to be sent out from a magnetic memory are therefore not possible because of the achievable read rate

^b5 in the case of a magnetic disk drive with byte-by-byte access is several orders of magnitude below the required read rate and other magnetic storage media are still due to less favorable positioning times

do worse.

For the sake of completeness, it should be mentioned here that by appropriately combining sub-channels transmission channels with higher transmission rates can also be formed. -,

Starting from a method of the type described in the introduction, the object of the invention is to provide a Specify a method for the serial transmission of information pages, which is used for the rapid transmission large volume of information in information distribution systems is suitable.

This object is achieved in that the data words containing the information pages in one Background memory can be saved in which each possible information page has one for the maximum, len sufficient memory area is allocated to allow the exchange and processing of the Information pages about the background memory takes place that those stored in the background memory Data words of the magazine are also transferred to a fast read-out memory and that the formation of the time division multiplex signal is carried out by reading out the data words from the readout memory.

The advantage of this method is the separation of administration (deletion, change, exchange) and> ^r > transmission of the information pages. In this way, the content of a magazine can be changed or exchanged without interrupting the sending of the magazine.

It is useful if for any number of associated information pages jo the first information page is transmitted again immediately after the last information page.

This measure results in a minimal amount on the receiving side, solely through the magazine umiang Conditional waiting time until the desired information page is received. Especially with magazines with a few Information pages, the rapidly circulating amount of information leads to short waiting times. Without these Measure when the magazine size is fixed is given and had to be filled with blank pages, unnecessary waiting time would elapse before the desired information can be taken from the periodically circulating data words.

It is advantageous that in each case during a multiplex time frame η successive data words of each magazine are read out from the read-out memory and temporarily stored in an output buffer, that during a period of π multiplex time frames from the output buffer, the data words belonging to the various magazines are individually sequential to form the Time-division multiplex signals are read out and that within this period or during (n - \) multiplex time frames, new information is written into the read-out memory without interrupting the transmission.

By reading out several bytes from the read-out memory at the same time, it stands for writing new or changed information pages from the background memory into the read-out memory for an ω longer contiguous period available.

This transfer takes place very quickly and without problems, since the data words belonging to a magazine are stored consecutively in the background memory and are also read out consecutively.
It is also advantageous if time segments are assigned to a magazine within each Mulliplcx time frame.

Because several data words of a magazine are transmitted within a multiplex time frame the cycle time for the magazine is shortened and thus the waiting time on the receiving side decreased. This can also be useful for displaying graphics pages in a finer grid, since a larger amount of information is required to display them, which is the case with the usual transmission speed the mean waiting time doubled.

It is advantageous if a circuit arrangement for implementing the method is characterized is that an output part is provided with a control unit and with a fast read-out memory, at that a specific memory area is provided for each magazine, and that the background memory over the computer and the control part are connected to the read-out memory via a data bus (FIG. 2).

With great simplicity, this circuit arrangement is characterized by a high degree of adaptability in terms of number and size of the magazine. Only the read-out part needs to be created using fast circuit technology.

Further advantageous refinements of the invention are specified in the subclaims.

An exemplary embodiment of the invention is illustrated by means of FIGS. 2 to 4 described. It shows

2 shows a block diagram of a system accordingly the invention,

F i g. 3 shows a block diagram of the readout part and FIG. 4 is a block diagram of the output memory. The system shown in FIG. 2 for sending out information pages consists of an information management part IET and a read-out part AUT. In the information management part IET , various input stations BIG, for example screen devices, are connected to a computer COM . The computer takes over the management of the information coming from the input locations BIG , these can be Τεχί graphics or image pages, assigns them to the desired magazine taking into account predetermined management criteria and transfers them to a background memory HSG connected to the computer. A magnetic disk storage, for example, is suitable as background storage. Each information page is assigned a fixed memory area in the background memory, which is designed for the maximum possible amount of information on a page. This enables complete information pages with different amounts of information to be exchanged. If a magazine has been completely created, it is transferred to the readout memory ASP of the readout unit A UT . Only the data words are transferred to the readout memory. The empty memory locations of the background memory are not taken into account. All functions that are related to the cyclical readout of this memory are initiated by the control part STE of the readout part, which regulates the sequence of all time-critical functions , without the assistance of the computer COM

In Figure 3, a more detailed block diagram of the Ausleseteüs A UT is illustrated as a read only memory ASP is a fast semiconductor memory uses the base addresses for the individual magazines allocated memory areas are stored in a magazine base address memory MBA This is a ROM, PROM or RAM can be. The output of the magazine base address memory is with a first

Input of an address comparator AAD connected. A magazine word counter MWZ is assigned to each magazine. The first magazine word counter MWZX is assigned to the first magazine. The relative addresses, also called offset addresses, of the individual magazine words are determined in the magazine word counter. The output of the first magazine word counter MWZX is connected to the distance address bus DIB via a data bus with a first word counter separation stage IVTS1. Of the other magazine word counters 2 to 100, only the last magazine word counter MtVZlOO is shown, which is also connected to the distance address bus DIB via the associated word counter separation stage WTS 100. The 98 additional magazine word counters (not shown) are switched on in the same way. The offset address bus DIB is connected to a second input of the address adder AAD , the output of which is connected to the address input EAD of the read-out memory ASP . The distance address bus DIB is routed to a distance address port DIP. A magazine counter MAZ is provided which is controlled by a clock generator TG and whose outputs form the magazine address bus MAB. The MAZ magazine counter counts up to 104, which corresponds to a magazine size of 100; a synchronization part of 3 bytes and a backup byte. The magazine address bus MAB is connected to an address input of an output device AEI , which is connected to the data output of the read-out memory ASP and a data port DAP via a data bus DAB . The magazine address bus MA B is connected to the address input of the magazine base address memory MBA, a magazine address port MAP, via a bus separation stage BTR . connected to the address input of a magazine end address memory MEA and various decoding stages DEC , of which only a first decoding stage DECX is shown. A single magazine word A-ZWZ is connected to the offset address bus via a word counter separator via the decoder DEC, while all other word counter separators are switched to high resistance. The Datcncingang of Magazinendadressen memory MEA is a Distanzendadressenbus DEB to a Distanzendadressenport DEP connected to the output of the Magazinendadressenspeichers MEA is connected to a first input of an address comparator ADV, whose second input is connected to the Distanzadressenbus DLB. If the addresses are the same, the address comparator ADV emits a pulse at its output. The output of the address comparator ADV is connected to the reset input REX of the first magazine word counter MWZX via a first AND gate AND \. The second input of the first AND gate is connected to the first output of the first decoder DEC 1. The reset inputs of the other magazine word counters are switched on in the same way, with the corresponding output of the address comparator being switched to all other AND gates (not shown) releases and for seven more cycles a logic zero outputs the output of the cycle counter ZYZist the bus separation BTR connected to the enable inputs EWT word separation stages and a connection point £! Pherausgeführt All address and data ports are connected to the computer COM of the information management part. The serial data stream comprising 100 magazines is output at the output AD of the output device Λ El.

In the example given, the ϊ reading in and reading out of the data should not be byte by byte but in in the form of data blocks comprising 8 bytes. One data word corresponds to one here Byte = 8 bits. First, a readout process will be described. It is assumed that

have already been written into the read-out memory in all magazines. At the beginning of a multiplex frame, the magazine counter MAZ causes a predetermined synchronous sequence comprising 3 bytes to be sent out by the output device Af /.

r> Then a byte of the first magazine is sent out. For this purpose, the outputs of the first magazine word counter MWZX are switched to the distance address bus via the magazine address bus MA B and the first decoder DECX. The base address of the memory area of the first magazine is also called from the magazine base address memory MBA via the magazine address bus. Both addresses are added in the address adder AAD and given to the address input of the read-out memory. An 8-byte-wide data block is read from the read-out memory and transferred to the output unit AE1. Here the first of the 8 bytes is sent out after the conversion into a serial bit sequence, while the other seven bytes

κι be cached. All magazines are now called up one after the other, the first byte is sent out and the other seven are temporarily stored in the output device AE1. If the last data block of a magazine has been read out,

π the address comparator emits a pulse that The corresponding magazine word counter is reset and the first one again in the next readout cycle Data block of the same magazine retrieved from the readout memory.

By using separate magazine word counters, the amount of information in each magazine /. Is sent out cyclically without a break. After each read-out cycle, bus separation is carried out by the BTR bus separation stage; at the same time, all word counters are

* "· Isolation stages WTS switched to high resistance via their enable inputs EWT . While the stored bytes of the magazines are called up and sent out from the output device, the COM computer can use the

>'· Address and data ports changed magazines are entered in the read-out memory ASP . Since the different bytes of a magazine are available one after the other in the background memory, the entry is made very quickly. In principle, it is not necessary to enter or read out several bytes in parallel in the read-out memory, but this achieves a much faster input of magazines into the read-out memory

After a magazine has been entered, the relative end address of the magazine is entered into the magazine end address memory MEA via the distance end address port DEP. The magazine word counter of the corresponding magazine is reset and the transmission of the new magazine begins with the first byte.

f> 5 The output device AEI is shown again in more detail in FIG. 4. It contains an output buffer memory A UB to which the data are fed via the data subs DAB. In the present

For example, the second to eighth bytes are fed directly to the output buffer, while the first byte is fed directly to a data output selector D / 45 via a sub-bus DABR branched off from the data bus DAB. In addition, the output device contains a synchronous generator SYC, which generates the aforementioned 3-byte synchronous part of a multiplex frame, a parity generator PAG, which ends the multiplex time frame with a backup byte. The outputs of the data selector, the synchronous generator and the parity generator are implemented in three-state logic (in the third state the outputs are high-resistance) and can therefore be switched to a common output bus AUB . The output bus is connected to a parallel-to-serial converter, which converts the data words, which are present in parallel byte by byte, into serial data and outputs them at its output AD . The magazine address bus is routed to the output buffer, the synchronous generator and the parity generator. The data selector is connected to the cycle counter ZVZ, not shown in FIG. 4, via a cycle counter bus ZYB.

If a new data block of 8 bytes is read from the read-out memory, the first byte is fed directly to the data selector DAS , which switches it through to the parallel-serial converter. The parallel-serial converter outputs the first byte in serial form. The next magazine is now called up via the magazine address bus. The first byte of the next magazine is switched through again. After all the first bytes of all magazines have been sent out, a backup byte generated by the parity generator follows.

In the next cycle, the next of the remaining seven bytes of the data block read out last is called up again via the magazine address bus. The data selector DAS. Controlled via the cycle counter bus ZYB, sends the second byte of the data block, this is the next saved byte in the readout buffer AUB, to the parallel-serial converter, which outputs it in serial form at the ADzbgtbl output. In the same way, the second bytes of the following magazines sent out. This process is repeated until aüe ah! Bytes of the available magazines have been sent out. During the transmission of the second to eighth data words of all 100 magazines, i.e. for seven cycles, new information can be written into the read-out memory. After these seven cycles, in which the data were removed from the read-out buffer, there again follows a cycle of the duration of a multiplex time frame in which new information is transferred from the read-out memory / 45P to the output buffer / 4L / ß.

For this purpose 3 sheets of drawings

Claims (8)

Patent claims: 1. A method for the cyclical transmission of information pages combined to form magazines, in which the data words of several magazines are combined to form a time-division multiplex signal, characterized in that,
that the data words containing the information strings are stored in a background memory (HSP) in which each possible information page is assigned a memory area sufficient for the maximum page size
that the exchange and processing of the information pages via the background memory (WS / tracked, that the data words of the magazines stored in the background memory (HSP) are also transferred to a fast read-out memory (ASP) , and that the formation of the time-division multiplex signal by reading out the data words from the Readout memory 2. The method according to claim 1, characterized in that that for each magazine with any number of the associated information pages immediately after the last information page, the> 5 first information page is transmitted again. 3. The method according to claim I or 2, characterized in that that in each case during a multiplex time frame η successive data words of each magazine are read from the read-out memory (ASP) and temporarily stored in an output buffer (AUB), that during a period of η multiplex time frames from the output buffer (AUB) the data words associated with η different magazines are read out individually one after the other to form the time-division multiplex signal
and that within this period or during (n- 1) multiplex time frames new information can be written into the read-out memory (ASP) without interrupting the transmission. 4. The method according to any one of the preceding claims, characterized in that one Magazine can be assigned several time segments within each multiplex time frame. 5. Arrangement for performing the method according to one of the preceding claims 1 to 4, with a computer to which at least one input station is connected, and with a Background memory, characterized in that that an output part (AUT) with a control unit (STE) and a fast read-out memory (ASP) is provided, in which a specific memory area is provided for each magazine, and that the background memory (HSP) via the computer (COM) and the control part (STE) is connected to the read-out memory (ASP) via a data bus (Fig. 2). 6. Arrangement according to claim 5, characterized in that a magazine base address memory (MBA) is provided which contains the base addresses of the memory areas assigned to the individual magazines and that each magazine has a counting device for addressing the in the assigned memory area of the read-out memory (ASP) stored data words is provided. 7. Arrangement according to claim 5 or 6, characterized marked, that the base addresses of the memory areas of the read-out memory (ASP) are stored in a magazine base address memory (MBA) that a magazine word counter (MWZ) is provided for each magazine, which forms the offset address of the respective memory location in the assigned memory area of the read-out memory (ASP) that the outputs of the number magazine word counters (WTSX to WTSXW) are connected to an offset address bus (DIB) which is connected to the first input of an address adder (AAD) , that the second input of the address adder (AAD) is connected to the output of the magazine base address Memory (MBA) is connected, that the output of the address adder (ADD) is connected to the address input of the read-out memory (ASP) , that a data bus (DAB) connects the readout memory (ASP) with an output device (AEl) and with a data port (DAP) that an address comparator (ADV) is provided, the first input of which from a magazine end address memory (MEA) the maximum Distance address of the respective magazine to be read is supplied, that the second input of the address comparator (ADV) mh is connected to the distance address bus (DlB) , that the output of the address comparator (ADV) via a decoder (DEC) and an AND gate (AND) with the Reset input (RE) of the associated magazine word counter (MWZ) is connected and, if the addresses are the same, emits a reset pulse that is connected to a clock generator (TG, / a magazine counter (MAZ) , which determines the multiplex time frame and whose outputs form the magazine address bus (MAB) which connects directly to the output device (AEI) and via a bus separation stage (BTR) to the magazine end address memory (MEA) and to the decoding stages (DEC 1, ...) n is that a cycle counter (ZYZ) is connected to the transmission output of the magazine counter (MAZ) , that the cycle counter cancels the bus separation (BTR) for a cycle of the duration of a multiplex time frame and the bus separation (n - 1) cycles ( BTR) and the magazine word counter isolating stages switches to high resistance, and that the magazine end address memory (MEA) via a distance end address bus (DEB) and a distance end address port (DEP), the distance address bus (DIB) via a distance address port (DIP), the magazine address bus (MAB ) after the bus separation stage (BTR) are connected to the computer fCOM ^ via a magazine address port (MAP) and the data address port (DAP). 8. Arrangement according to claim 7, characterized in that that the output device (AEl) contains an output buffer (AUB) which stores at least (n - 1) code words for all magazines, that the Ausgabözwischenspeicher (n - 7) via a byte-data bus (DAB) is connected to the read-out memory, that the first byte from the data bus via a Datenteilbus (DAB] is directly connected to a data selector (DAS) and the output of the output buffer with a second input of the data selector is connected that the data selector the data words of the Magazine issues as a time division multiplex signal and is controlled via a cycle counter bus (ZYB) that a synchronous generator (SYG) is provided which generates a synchronous part (S YT) at the beginning of the time division multiplex signal that a parity generator (PAG) is provided, which adds security byte at the end of the time division multiplex signal ti.i, and that the three-state data outputs of the synchronous generator (SYG), the data selector (DAS) and the parity generator (PAG) are interconnected and fed to the input of a parallel-to-serial converter (PSU) which has its output (AD) outputs serial time division multiplexed signal.