WO2002103945A2

WO2002103945A2 - Communication system, communication station, data input/output unit

Info

Publication number: WO2002103945A2
Application number: PCT/EP2001/008509
Authority: WO
Inventors: Anatoly E. Barulin
Original assignee: Digital Flow Ag
Priority date: 2001-06-15
Filing date: 2001-07-23
Publication date: 2002-12-27

Abstract

A communication system is provided that comprises at least one synchronous data transmission TDM line implemented in the form a loop, successively wired user data input/output units and a communications station. The communications station assigns a communication channel occupying the same time slot in synchronous data transmission lines which these users are connected to maintain communication between users. Furthermore, a communication station is described that comprises a multiplexers, one per each data transmission TDM line connected to the communications station, and a control device. Data coming from synchronous transmission lines is fed to the respective data inputs of each of the multiplexers and data from outputs of the multiplexers is fed into the respective synchronous data transmission lines while switching is controlled by the controlled by the control device with its outputs connected to the address inputs of the multiplexers. Additionally, an input/output unit is described that comprises a multiplexer and control device with data transmitted via a synchronous data transmission line fed to one of the inputs of the multiplexer and simultaneously to all users connected to this input/output unit.

Description

Communication System, Communication: Station, Data Input/Output Unit

This invention relates to the sphere of telecommunications hardware and may be used to automatically transport digital data via Time Division Multiplex lines.

There is a system, which provides for digital data exchange between remote users. It comprises a communications line formed by a twisted pair cable with digital data input/output units and a communications station linked in a loop. Digital data is transmitted via byte-interleaved time division multiplex links. All input/output units are assigned addresses and receive only the information transmitted on a channel, which has the same address. The communications station writes input data from the communication line to the receive buffer and from there it is carried to the send buffer so as to transport the data transmitted to the switch from one input/output unit via a channel between this unit and the switch into a communication line in the channel for transmission of data between the switch and the second input/output unit (U.S. patent No. 4,144,410, 1979, Int. Cl. H04J3/08).

The drawback of this system is that it does not provide for dynamic alteration of the carrying capacity of data transmission channels connecting users.

There is a communications station, which connects and disconnects byte- interleaved TDM communication lines coming to the communications station in serial form from input data transmission lines to be sent by the communications station in serial form to output data transmission lines. The communications station has inlet stores, one for each of the input data transmission lines, outlet stores, one for each of the output data transmission lines, output shift registers, one for each of inlet stores, inlet shift registers, one for each of outlet stores, multiplexers, one for each of outlet stores, and a switch control module. Input data transmission lines are connected to inputs of the respective inlet stores while output data transmission lines are connected to outputs of outlet stores. Outputs of the switch control module are connected to control address inputs of inlet stores, control address inputs of outlet stores and control inputs of multiplexers. Channels are switched as follows: within the first cycle, data from data transmission lines is stored at inlet stores, within the second cycle, data read from slots of inlet stores with address transmitted from outputs of the switch control module to address inputs of inlet stores is transmitted in parallel form to outlet shift registers related to the respective inlet stores, and further the data from outputs of the outlet shift registers is transferred in serial form to inputs of multiplexers related to the respective outlet stores, multiplexers select data transferred to the respective inlet shift registers in accordance with control signals communicated from outputs of the switch control module to control inputs of multiplexers, and data fed to the said inlet shift registers in parallel form is carried to outlet stores to be stored in memory slots with address transmitted from inputs of the switch control module to address inputs of outlet stores. Within the third cycle, data from outlet stores is transmitted to output lines (U.S. patent No. 4,038,497, 1975, Int. Cl. H04J3/00).

The drawback of this communications station is that the switching entails multiple transformation of the format of transmitted data and its storage thus complicating the device.

There is a data input/output unit comprising a receive module to receive data from the input communication line, send module to send data to the output communication line, user data send and receive modules, receive shift register and send shift register, and control device, whereas, according to commands from the control device, data from the data transmission channel in the input communication line to be relayed to the user is stored at the inlet shift register during one cycle and is transmitted to the user during the next with data from the user being first stored at the outlet shift register and then, according to commands from the control device, is sent to the output communication line in the respective output data transmission channel (U.S. patent No. 4,144,410, 1979, Int. Cl. H04J3/00). The drawback of this data input/output unit is that it entails intermediate storage of data both when the same is received from the user and sent to the user via the data transmission line, thus complicating the device.

The technical objective of the communication system is to provide users with channels of different carrying capacity.

The technical result of the communication system is the assignment to the user a channel with variable carrying capacity in the data transmission TDM lines to connect to another user.

The technical objective of the communications station is to connect communication channels occupying the same time slots in different data transmission lines with zero blocking probability.

The technical result of the communications station is the transfer of data from one data transmission TDM line to another with the same time-shared allocation of data within a frame.

The technical objective of the input/output unit is to eliminate limits on the use of channels in data transmission lines by the user.

The technical result of the input/output unit is the use of randomly assigned channels in the data transmission TDM line to transmit data to/from the user.

The proposed communication system (Fig. 1 ) comprises at least one synchronous digital data transmission TDM line 1 in the form of a loop, user data input/output units 2 successively located thereon and communications station 3 with communication between users maintained by the communications station assigning a communication channel occupying the same time slot in the synchronous data transmission lines which these users are connected to. To set up a communication session between the users connected to same input/output unit 2, n pairs of adjacent channels are assigned with data to/from the first user transmitted in the first channel and data to/from the second user transmitted in the second channel respectively, and the communications station exchanging data between these channels.

To eliminate the limits on data transmission line length when the system is designed and implemented, controlled delay device 4 is connected to each circular data transmission line in series with other devices (Fig. 2).

The proposed communications station (Fig. 3) comprises N multiplexers 7, one per each L1-LN synchronous data transmission line and control device 8 with data from L1-LN synchronous data transmission lines sent to the respective data inputs of each of multiplexers 7 and data from outputs of multiplexers 7 sent to the respective L1-LN synchronous data transmission lines, and the switching is controlled with control device 8 whose outputs are connected to the address inputs of multiplexers 7.

To set up a communication session between the users connected to same input/output unit 3, one channel in synchronous data transmission line 1 is not enough. Such users are assigned two adjacent time-shared channels with information being substituted within the communications station. To ensure substitution of data transmitted in the adjacent channels in the synchronous data transmission TDM line, communications station 3 comprises additional substitution modules 19 whose inputs are connected to the respective inputs of multiplexers 7, and control inputs of substitution modules 19 are connected to the respective outputs of control device 18 (Fig. 4).

The proposed input/output unit 2 (Fig. 5) comprises multiplexer 13 and control device 14 with data transmitted via synchronous data transmission line 1 sent to one of the inputs of multiplexer 13 and simultaneously to all users connected to this input/output unit 2, with data received from users sent to other inputs of multiplexer 13 to be transmitted to other users via synchronous data transmission line 1 , control commands sent from outputs of control device 14 to the address inputs of multiplexer 13 and data from the output of multiplexer 13 sent into synchronous data transmission line 1.

In the input/output unit above, the users receive all information carried in the synchronous data transmission line, which is not always acceptable. To bar a user from information intended to other users, the input/output unit 2 contains additional demultiplexer 15 and data transmitted via synchronous data transmission line 1 is sent to one of inputs of multiplexer 13 and simultaneously to the data input of demultiplexer 15, control commands from outputs of control device 14 are sent to the address inputs of demultiplexer 15, with demultiplexer 15 distributing data between the users (Fig. 6).

To simplify generation of synchronization codes in user data transmission lines, should channels be selected by demultiplexer 15, the input/output unit additionally includes buffer 16 with its input connected in to the input of demultiplexer 15 and the respective input of multiplexer 13, outputs connected to the respective outputs of demultiplexer 15 and the control input connected to the respective output of control device 14 (Fig. 7).

When different structures of data transmission flows are used in a loop and user communication lines, for example, a flow with bit-interleaved synchronous multiplexing in a loop and flows with lesser speed without multiplexing in user communication lines, data from incoming flow is transmitted to the inputs of user data receive and send modules within a frame at different time depending on the selected input channel, thus complicating generation of a user data transmission cycle. To generate signals of the required duration upon transmission of data to the user, input/output unit 2 is supplemented with triggers 18 with their inputs connected to the outputs of demultiplexer 15 and store inputs connected to the respective outputs of control device 17 (Fig. 8).

When a synchronous data transmission line is used to transmit data between users and input/output unit 2, then the data from the user is delayed relative to the data transmitted to the user for the time of signal propagation in this data transmission line. To synchronize data transmission within a communication system in order to compensate for the said delay, additional delay device 1 is included in input/output unit 2 with data coming from the synchronous data transmission line 1 to the input of the delay device 12 and the output of the delay device 12 connected to the respective input of the multiplexer 13 (Fig. 9).

To synchronize receipt of data coming to inputs of multiplexer 13 from users located at various distances from input/output unit 2, input/output unit 2 comprises additional controlled delay devices 17 with their outputs connected to the respective inputs of multiplexer 13 and control inputs of controlled delay devices 17 connected to the respective outputs of control device 14 (Fig. 10).

The list of Figures and drawings.

The proposed communication system operates as follows. To set up a communication channel, the calling user equipment send a message or a number of messages in dialogue regime via input/output device 2 in a channel used for signaling in synchronous data transmission line 1 to communications station 3 with information regarding the called user; communications station 3 exchanges messages with the equipment of both users in a similar way regarding the assignment to both of them one or more time-shared channels occupying the same time slots in data transmission lines which the users are connected to. During the session, each user receives in assigned channels information from circular synchronous data transmission line 1 and further sends its owns information, which replaces the received information, via the same channels.

If users are connected to the same data transmission line, then one part of circular synchronous data transmission line 1 is used to transport data from the first user to the second one in the respective channels, and the same channels in the second part of circular synchronous data transmission line 1 transport data from the second user to the first one. If users are connected to different synchronous data transmission lines 1 , data from the first user is carried via assigned channels to communications station 3 which transports this data to channels occupying the same time slots in data transmission line 1 , which the second user is connected to. Input/output device 2, which the second user is connected to, receives data transmitted to it by the first user from the channels assigned for this particular communication session and replaces it with data transmitted by the second user to the first one. This data is carried to the respective inputs of communications station 3, which transports it into data transmission line 1 , which the first user is connected to. The same channels are used to transmit data from the second user via data transmission line 1 from communications station 3 to the first user as to transmit data from the first user to communications station 3, and communications station 3 replaces data from the first user to be transmitted to the second user in the respective channel with the data received from the second user to be transmitted to the first one.

To set up a communication session between the users connected to same input/output unit 2, n pairs of adjacent channels are assigned to them for data transmission. Input/output unit 2 receives data transmitted by the second user to the first one from the first channel in each pair of channels and transmits data from the first user to the second one in the same channels by replacing the received data with it. Similarly, input/output unit 2 receives data transmitted by the first user to the second one from the second channel in each pair of channels and transmits data from the second user to the first one in the same channels by replacing the received data with it. Data exchange in the said pairs of channels is supported by communications station 3.

Communications station 3 operates as follows (Fig. 3). For a communication session between any two users connected to different input/output devices 2, the communications station assigns one or more channels occupying the same time slots in synchronous data transmission lines L1-LN, which these users are connected to. Data transmitted in the assigned channels by the user, connected to the Lk synchronous data transmission line, is fed via this synchronous data transmission line to the same inputs of all multiplexers 7. In accordance with control signals received at the address inputs of multiplexers 7 from outputs of control device 8 to be transmitted into the Lm synchronous data transmission line, which the second user is connected to, the respective multiplexer 7 selects data received at its k-input. Thus, subject to commands received at the address inputs of multiplexers 7 from control device 8, communications station 3 will feed data into one or several data transmission lines in a channel occupying the same time slot as the channel used to transport the data to communications station 3.

To exchange data between users connected to the same input/output unit 2, data from the first and the second user in two successive time-shared channels (data from the first user in the first channel and data from the second user in the second) is carried to the input of respective substitution module 19 (Fig. 4), which, pursuant to commands received at its control input from outputs of control device 8, replaces data with data received at the communications station in the first time-shared channel is transmitted in the second channel from the output of substitution module 19 to the respective inputs of multiplexers 7, and data received at communications station 3 in the second time-shared channel is transmitted in the first time-shared channel. In its turn, multiplexer 7, pursuant to control signals from outputs of control device 8, sends this data into synchronous data transmission line 1 , which users are connected to. Thus, data transmitted from the second user to the first one is fed into data transmission line 1 in the first time-shared channel, and data transmitted by the first user to the second one is fed in the second time-shared channel. In its turn, to establish communication between the users connected to different input/output units 2, substitution module 19, pursuant to control signals from outputs of control device 8, passes the data fed to its input without substituting the same, which permits channels occupying the same time slots in respective synchronous data transmission lines 1 to be allocated to such users for a communication session.

Input/output unit 3 operates as follows (Fig. 5). Information coming from synchronous data transmission line 1 is fed to the inout of multiolexer 13 and simultaneously to all users connected to this unit. Thus, each user receives all information disseminated in synchronous data transmission line 1. Data transmitted by each user connected to this input/output unit 2 is sent to the separate input of multiplexer 13. Pursuant to commands from control device 14 fed to the address inputs of multiplexer 13, multiplexer 13 forms a succession of data from data fed to its inputs to be sent further into synchronous data transmission line 1. In the absence of information intended to users connected to this input/output unit 2 in synchronous data transmission line 1 , multiplexer 13, pursuant to commands from control device 14, passes information from synchronous data transmission line 1 fed to its input unchanged.

If one or more channels in synchronous data transmission line 1 are assigned to establish communication between a user connected to this input/output unit 2 and another user, then multiplexer 13, on a command from control device 14, replaces data received at its input from synchronous data transmission line 1 with user data in the respective time intervals. For this purpose, user information has to be fed to the respective input of the multiplexer 13 in the time interval allocated to the user for communication.

Additional demultiplexer 15 included in input/output unit 2 (Fig. 6) selects, pursuant to commands from outputs of control device 14 received at its address inputs, only data transmitted in synchronous data transmission line 1 in channels assigned to this user for a communication session from data coming to its input from the synchronous data transmission line 1.

Synchronization codes transmitted in the zero channel in synchronous data transmission line 1 are fed into user data transmission lines through additionally introduced buffer 16 (Fig. 7). These codes are used to generate a frame synchronization code when a synchronous data transmission line is used to exchange data between the user and input/output unit 2. When synchronous lines, which carry data at a lesser speed then in synchronous data transmission line 1 , are used for data exchange between the user and input/output unit 2 (Fig. 8), information selected by demultiplexer 15 from the respective channel of synchronous data transmission line 1 is written to trigger 18 on a signal fed to write inputs of trigger 18 from the output of control device 14. Periodicity of signals fed to write inputs of trigger 18 coincides with transfer periodicity of information bits related to the selected communication channel in the synchronous data transmission line. In this case, trigger 18 maintains electric potential corresponding to the content of the transferred information bit within a time interval provided for in the synchronous data transmission line between the user and input/output unit 2 for the transfer of one information bit.

When a synchronous data transmission line is used to exchange data between the user and input/output unit 2, information from users is carried to the respective inputs of multiplexer 13 with a delay relative to information coming from synchronous data transmission line 1. This delay is caused by the time required for information propagation through equipment and user communication lines. Delay device 12 (Fig. 9) delays for that time information coming from the synchronous data transmission line to the respective input of multiplexer 13, thus enabling multiplexer 13 to replace information in channels assigned to users of this input/output unit 2 with data transmitted by these users on control signals from control device 14.

The delay occurring upon propagation of information through the equipment and user communication lines will differ depending on the remoteness of each user connected to this input/output unit 2 via synchronous data transmission lines. Controlled delay devices 17 (Fig. 10) delay data coming from users thus ensuring that data from all users comes from their output to inputs of multiplexer 13 synchronously. Delay time is controlled by signals from control device 14.

The proposed communication system is implemented with existing equipment used in other communication systems. A synchronous data transmission line is formed by an electric cable in the form of "a twisted pair". Data via a synchronous data transmission line is transmitted at a speed of 2,048 kbit/sec (primary data transmission channel) with time division of this data flow into 32 channels with a 64 kbit sec carrying capacity each (main digital channel - MDC), wherein the zero channel is used to transmit synchronization codes and the sixteenth channel is for signaling. At speeds of 4,096, 8,192 and 16,384 kbit/sec and higher, the bit-interleaved multiplexing of several primary data transmission channels is implemented. To transmit data via a synchronous data transmission line, the transmitted information undergoes linear coding.

In the communication system, the synchronous data transmission line has the form of a loop. The length of the loop taken is to accommodate a whole number of data transmission frames. To interact with outside users, the frame structure is to be similar to that adopted in other systems, for example, in ISDN communication systems, wherein the frame duration is 125 microseconds. For this purpose, the electric length of the data transmission line must be divisible by 125-microsecond interval.

To eliminate a need to take the line length into account when a system is designed and implemented, each circular data transmission line includes a controlled delay device connected in series with other devices. This device is implemented on the basis of IDT7203L15TPI FIFO (first input first output) memory chips and is a structural part of the communications station.

Structurally the communications station comprises a single-board PCM-4825 computer commercially manufactured by ADVANTECH, as control device 8, and a switching device implemented on the basis of programmable series XC9500 logic matrixes commercially manufactured by XILINX. The switching device (Fig. 11) consists of line receivers 5, line transmitters 6, multiplexers 7 and substitution modules 19, with inputs of each line receiver 5 connected to the output of the respective line, outputs of each line receiver 5 connected to inputs of respective substitution modules 19, outputs of substitution modules 19 connected to the same inputs of all multiplexers 7 and the respective input of the signaling channel of control device 8, input of each transmitter connected to the output of respective multiplexer 7 and the respective output of the signaling channel of control device 8.

Communications station 3 operates as follows. Information in communication channels is transmitted in frames of equal duration whose beginnings upon transmission of information into the channel coincide with the arrival of frames from the channels owning to the same time position of all the time-shared channels when they are received from and transmitted into the lines. Upon user's request to establish a communication session with a user connected to another synchronous data transmission line 1 , the control device of communications station 8 assigns both users the same time-shared channels in their lines for the session with notification sent via signaling channels in their data transmission lines 1. During the communication session, the control device sends to the address inputs of a pair of multiplexers 7, whose outputs are connected to the communication lines servicing the users, for the transit period of the time-shared channel assigned to the communication session, via the communications station, control codes, which provide for exchange of data transmitted in the channels occupying the same time slots in these data transmission lines.

Substitution module 19 is shown in Fig. 12. The substitution module comprises delay device 20 for the duration of a channel interval and two switches 21 with one input of first switch 21 connected to the module input, the output of this switch connected to the input of delay device 20, the output of delay device 20 connected to the second input of the first switch and the first input of the second switch, the second input of the second switch connected to the module input, the output of the second switch connected to the module output, the switch control inputs connected together and to the control input of the control device.

Communications station 3 with substitution modules 19, upon switching in the regimes described hereinabove with assignment of one time-shared channel to users being switched, operates similarly to the above with the exception of information flows within loops additionally coming through delay devices 20, thus their delay is to be compensated for by controlled delay device 4. Whenever two adjacent time-shared channels are required for a communication session between two users, control device 18, with a control signal during transfer of the second time-shared channel through substitution module 19, changes the status of the switches with a signal from the output of delay device 20 coming to the delay device input and an input signal of the delay module coming to the module output bypassing the delay device. Thus, the information from the second channel is transmitted into the time interval of the first channel, and the information from the first channel is transmitted afterwards into the time interval of the second channel. As a result, upon further transfer via the loop, the outgoing information from the first user is coming to the second user, and the outgoing information from the second user to the first user.

Structurally input/output 2 (Fig. 13) comprises control device 14 implemented on the basis of commercially produced series C 51 microcontrollers and a logic device implemented on the basis of XC9500 programmable logic matrixes commercially produced by XILINX. The logic device comprises receive module 9, send module 10, user data user data receive and send modules 11 , signal delay device 12, multiplexer 13, control device 14, demultiplexer 15, buffer 16, controlled delay device 17 and triggers 18 with the output of receive module 9 connected to the input of signal delay device 12, the data input of demultiplexer 15, input of control device 14, and input of buffer 16, with outputs of demultiplexer 15 and buffer 16 connected to inputs of respective triggers 18, outputs of triggers 18 connected to inputs of respective user data receive and send modules 11 , outputs of user data receive and send modules 11 connected to inputs of respective controlled delay devices 17, the output of signal delay device 12 and outputs of controlled delay devices 17 each connected to its input of multiplexer 13, the output of multiplexer 13 connected to the input of send module 10, the address inputs of demultiplexer 15 and address inputs of multiplexer 13 connected to the respective inputs of control device 14 and the control input of buffer 16 connected to the respective output of control device 14. Input/output unit 2 operates as follows. Information coming out of the line to receive module 9 is decoded there from a linear code to a single-polarity code with 100% filling of the time interval and relayed in this form to the input of demultiplexer 15 as well as to the input of control device 14, controlled delay device 12 and buffer 16. Control device 14 identifies synchronizing information from incoming information and generates a sequence of control signals to operate demultiplexer 15, which selects information intended to the users connected to this input/output unit 2, multiplexer 13, which passes the information not intended to the users of this input/output unit 2 and information from certain users in channels assigned to them to the send module, as well as controlled delay device 17 and triggers 18.

Synchronization codes transmitted in the zero channel of a frame, via buffer 16, on a signal from control device 14, are transmitted simultaneously to inputs of user data receive and send modules 11 , and information in the assigned channels is transmitted to these inputs via demultiplexer 15 with the transmission direction to be determined by the codes from control device 14. Information in other channels is replaced with ones. Triggers 16, in accordance with synchronization signals coming to their control inputs from outputs of control device 14, form pulses corresponding to information bits in the user data transmission line from pulses corresponding to information bits in synchronous data transmission line 2.

The users replace the information transmitted to them with their outgoing information. The information coming from users is delayed relative to the incoming information due to the time required for the information to pass through the devices and user communication lines. Controlled delay device 19 is used to eliminate the differences in delays of signals coming from users into input/output unit 2. Delay device 12 delays transit information for that time, thus making it possible to replace the incoming information with outgoing in channels assigned to users of the said input/output unit by means of multiplexer 13 on control signals from control device 14. Send module 10 translates information coming to its input in a single-polarity code into a linear code and sends the same into the communication line.

The proposed set of inventions under a single innovative concept allows for modernization of existing communication systems and provision of each user with a digital data transmission line.

Equipment to be used in the communication system is implemented on the basis of the latest achievements in microelectronics and provides for effective utilization of data transmission channels.

The proposed set of inventions improves the quality of services rendered to users within various categories with no significant cost to the operator. The proposed equipment and technical solutions make it possible to carry out both partial and complete modernization of networks with the existing user communication lines kept intact.

The proposed set of inventions provides for significant increase in user information exchange, including a nonstatistical one. The equipment is characterized by improved manufacturability and reliability, is easy to operate and maintain.

Claims

1. . A communication system that comprises at least one synchronous data transmission TDM line implemented in the form of a loop, successively wired user data input/output units and a communications station, wherein the communications station assigns a communication channel occupying the same time slot in synchronous data transmission lines, which these users are connected to, to maintain communication between users.

2. The communication system claimed in claim 1 wherein an additional controlled delay device is included in the synchronous data transmission TDM line.

3. ^" A communications station that comprises n multiplexers, one per each data transmission TDM line connected to the communications station and a control device, wherein data coming from synchronous transmission lines is fed to the respective data inputs of each of the multiplexers, and data from outputs of the multiplexers is fed into the respective synchronous data transmission lines while switching is controlled by the control device with its outputs connected to the address inputs of the multiplexers.

4. The communications station claimed in claim 3 that comprises additional adjacent channel substitution modules with data from synchronous data transmission lines fed to their inputs and with their outputs connected to the respective inputs of the multiplexers and control inputs of the substitution modules connected to the respective outputs of the control device.

5. input/output unit that comprises a multiplexer and control device with data transmitted via a synchronous data transmission line fed to one of the inputs of the multiplexer and simultaneously to all users connected to this input/output unit and with data received from users to be transmitted to other users via the synchronous data transmission line sent to other inputs of multiplexer, with control commands sent from outputs of the control device to the address inputs of the multiplexer and data from the output of the multiplexer sent into the synchronous data transmission line.

6. The input/output unit claimed in claim 5 that contains an additional demultiplexer with data transmitted via a synchronous data transmission line sent to one of the inputs of the multiplexer and simultaneously to the data input of the demultiplexer, control commands from outputs of the control device sent to the address inputs of the demultiplexer, and with demultiplexer distributing data between the users.

7. The input/output unit claimed in claim 6 that includes an additional buffer with its input connected to the input of the demultiplexer and the respective input of the multiplexer, buffer outputs connected to the respective outputs of the demultiplexer and the control input connected to the respective output of the control device.

8. The input/output unit claimed in claim 6 that includes additional triggers with their inputs connected to the outputs of the demultiplexer and write control inputs connected to the respective outputs of the control device.

9. The input/output unit claimed in claim 5 that includes an additional delay device with data coming from the synchronous data transmission line to the input of the delay device and the output of the delay device connected to the respective input of the multiplexer.

10. The input/output unit claimed in claim 5 that includes additional controlled delay devices with data coming from the users to their inputs, their outputs connected to the respective inputs of the multiplexer and the control inputs of the controlled delay devices connected to the respective outputs of the control device.