RU2361362C2 - Light-guiding system for on-site communication - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to telephone communication and may be used for arranging telephone communications where the level of industrial and electromagnetic fields is high. For this purpose, commutation system "БЦК" is implemented as a modular structure having common bus. The said bus includes micro computer and other modules supporting system operation.

EFFECT: wide functional possibilities, improved quality of data transmission and acquisition channels and reduced weight and dimensions.

5 dwg

Description

The invention relates to the field of electronics and can be used to organize telephone communications on stationary and mobile objects.

The inventive intercom system is a small office PBX designed for use in a high level of industrial electromagnetic interference. The use of fiber-optic communication lines allowed us to solve the problem of electromagnetic compatibility, making the entire system insensitive to external interference, on the one hand, and, on the other, to prevent interference with equipment and systems located nearby.

The use of digital methods of speech transmission logically follows from the use of optical fibers, because only digital transmission methods make it possible to fully realize the advantages of fiber-optic communication lines: wide bandwidth, transmission of speech and command information over a single fiber, etc.

Currently, various types of automatic telephone exchanges are used on moving objects (ships, ships, airplanes), for example, ship KATS-40 is used on ships. (Directors N.F., Kaganovich A.A. Modern systems of intra-ship communication. St. Petersburg: Shipbuilding, 2001, P.222). A shipboard telephone exchange is a complex set of devices, the main part of which is a switching system that provides connecting subscribers of the telephone exchange with each other. The switching system of any automatic telephone exchange includes linear kits, a switching field, cord sets, control devices and signaling and calling devices.

The disadvantages of all existing exchanges are low noise immunity from electromagnetic pulses, a large hardware and cable redundancy.

The aim of the invention is to expand the functionality of the transmission and reception of information while reducing weight and size characteristics.

This goal is achieved due to the fact that in a system containing a switching subsystem, tract-forming equipment, a control device and a signaling and calling device, the switching field is made in the form of a central switching unit (BCC) connected to N subscriber terminals (telephone sets) by fiber-optic communication lines Moreover, the BCC is made according to the modular principle in terms of a structure with a common bus, which includes a microcomputer, a clock generator module, a subscriber module, a ringing module, a conference call module ide, a module for interfacing with urban telephone exchanges, the control microcomputer being made on a modular basis based on a microprocessor of the type КР580 ВМ80 in structure with a common system bus, and the microcomputer contains a clock generator, a central processor, a buffer of control signals and bus drivers, while the subscriber module consists of three identical channels, each of which contains a voice switch connected to the compaction device and a signal conditioner, a transmitting LED, and also through the bus connected to the device razuplot a signal conditioning apparatus and a receiving photodiode, wherein the receiving part of the subscriber’s apparatus consists of a photodiode connected in series with a signal amplifier, a synchronization device, a decoder, a signal amplifier and headphones, and the transmitting part contains an LED connected in series with an amplifier, a synchronization device, an encoder, an amplifier and a microphone, wherein the synchronization device is connected to an exchange circuit, which in turn is connected to an indication device and a device, containing information about the status of the controls.

Figure 1 presents the light guide system of intraobject communication. It consists of

1 - centralized switching unit (BCC);

2 - subscriber’s apparatus (AA), manager’s apparatus (AR), secretary’s apparatus (AC);

3 - optical fiber communication lines.

Figure 2 shows the functional diagram of the BCC, it includes a microcomputer:

4 - the module of the clock generator (MTG), containing the master crystal oscillator, which generates all the necessary synchronization signals, organizes the synchronous operation of all the modules BCC and AA;

5 - subscriber module (MA), which is designed to organize a physical communication flow with three subscribers and contains a subscriber switch, an optical shaper module and a receiver for each subscriber;

6 - module of ringing signals (MVS), which generates digital sequences, which, after decoding in the AA delta encoder, form tonal signals “Call-1”, “Call-2”, “Station answer”, “Call sending control”, “Busy” ";

7 - a conference communication module (ISS), which generates a digital signal encoding the sum of analog signals for each of the subscribers - participants of the conference call;

8 - a module for interfacing with city telephone exchanges (MST) interfaces the system with a wire telephone line (PLC) of a city telephone exchange.

Figure 3 shows the functional diagram of the control microcomputer.

It contains a 9 - processor, which is a functionally complete module organizing the logic of the entire system. The processor module contains a clock; CPU; control signal buffer; bus formers. The processor module sets the format of the system bus, standard for the microprocessor of the K580 series;

10 - read-only memory device with a capacity of 8 kbytes, made on the chips KR556RT5;

11 - operational memory device with a capacity of 4 KB on the chip K565RU2;

12 - the serial interface module with a timer contains

- two serial interfaces based on the KR580 BB51 chip,

- a three-channel counter - a timer based on a chip like KR580 VI53;

- interrupt subsystem providing two levels of vector interrupt with priority.

The serial interface module is designed to organize the exchange of commands in a serial format between the BCC and AA, and the timer sets the time interval for the MSG;

13 - the device for interfacing with the bus provides mutual conversion of levels between the TTL of the microcomputer and the CMD bus of the rest of the product.

Figure 4 shows the functional diagram of the subscriber module. The subscriber module (MA) is designed to transmit and receive voice and seal command information for three subscribers. MA consists of three identical channels.

The subscriber module includes a 14-voice switch; 15 - sealing device; 16 - control controller Rg; 17 - shaper; 18 - light emitting diode (LED); 19 - receiving photodiode; 20 - amplifier (shaper); 21 - decompression device; 22 - data bus.

Figure 5 shows the functional diagram of the subscriber's device. It contains

22 - photodiode; 23 - LED; 24, 25 - amplifiers; 26 is a synchronization device; 27, 28 - decoders; 29, 30 - terminal amplifiers; 31 - handset; 32 - microphone; 33 is a diagram of an exchange; 34 - indication amplifiers; 35 - display device controls; 36 - power supply.

As a method of digital speech conversion, adaptive delta - modulation with digital inertial compilation is used. The clock frequency is 64 kHz. The operating wavelength range of the optical fiber communication lines is 0.7-1.0 microns. Maximum line length 300 m.

The control device uses a modular microcomputer based on the KR580 VM80 microprocessor. The system is powered by AC 220 V - 50 Hz.

In ROM microcomputer 10 is a program that determines the functioning of the system. The microcomputer in turn interrogates the keypad of all subscriber units on which the handset is off-hook and serves by pressing the control buttons AA and AP. At the same time, information is updated on the information bodies of the Autonomous Republic of Azerbaijan and in the control registers of the MAKS.MSG.

The structure of the common bus BMU includes:

- 8-bit unidirectional bus address addresses of external devices (SHAVU);

- 8-bit bidirectional data bus (BH);

- 48-bit voice information bus (SR);

- bus control and synchronization (SHU).

On SHAVU microcomputer exposes the address of the external device with which the exchange will be carried out. A data byte is transferred from the microcomputer to the control unit or from the control unit to the microcomputer via the data path. Transmission control is set by the INP, OUT signals on the control panel.

The reliability of the information on the SD is confirmed by the signals WR, DBIN.

On the voice information bus are present

- voice information from each of 32 AA, AR and AC in the channel-wire format - a total of 32 lines;

- 8 lines from the conference communication module, one for each subscriber listening to the ISS signal;

- 6 lines of service ringing signals “Pause”, “Call-1”, “Call-2”, “Answer station”, “CONTROL of making a call”, “Busy”;

- 1 line - reserve

The control bus also includes synchronization signal lines, Prd, Prm lines — transmitting and receiving commands in a serial code, as well as the “Interrupt” line, along which an encoded signal is generated that is directly listened to in the subscriber’s phone when calling him from the AP.

Signal structure in optical communication lines.

To reduce the number of communication lines between the BCC and AA, the transmission of voice and command information through one fiber with a temporary seal is used.

For communication between the BCC and AA, it is necessary to organize three independent transmission channels:

speech; - teams; - service signal "Interruption". In BCC, all three signals are generated synchronously in the NRZ code with a clock frequency of 64 kHz. Since the NRZ code (the code without returning to zero) is poorly adapted for transmission along fiber-optic lines (there are no cyclic synchronization signals, the harmonic level of the clock frequency is small and unstable), all three channels are compressed into one stream in the NRZ code, and then encoded using a modulator in discrete pulse-width code (DSHIK). With this encoding method, each cycle interval (duration t = 15.6 μs) is divided into n + 1 cycles of duration τ = 1 / n + 1 (n is the number of simultaneously transmitted channels). Then the cycle sync encoded duration _^3/4 τ, a pulse corresponding to the transmitted logic "1" is 2 / 4τ, and for "0" - 1 / 4τ. At n = 3, the transmission speed in terms of one channel increases by 16/3 times, but the clock signal stably contains cyclic clock pulses, the clock frequency (along the leading edge of each pulse) is easily distinguished and the log is equally probable. "0" and the log. “1” in each channel for the formation of a zero (reference) level of comparing requires integration time of the order of the period of the low-frequency signal in the channel, and the fluctuation of the reference level in the worst case does not exceed ± 3/32 of the pulse amplitude.

An additional advantage of the adopted coding is the simplicity of the formation and decoding of a discrete PEC in comparison with other known coding methods (codes such as nBmV).

Channel 1 is used to transmit delta-encoded speech from AA to BCC and vice versa. Channel 2 is used to transmit command information from the BCC to AA and vice versa. Channel 3 is used to transmit the “Interruption” signal from BCC to AA (channel 3 = 0 in the direction from AA to BCC).

In each cycle, only one bit of command information can be transmitted. Therefore, the start-stop transmission method implemented by the receiving part of the KR580 BB51 chip is used to transfer commands from AA to the BCC, and the modified start-stop method, also implemented on the KR580 BB51 type chips, is used to transfer commands from the BCC to AA. Exchange formats with AA and AR are different, because the amount of information exchanged by the CAP is significantly larger due to the presence of numerous indicators and controls.

Command information from the BCC to AA is transferred in the form of an eight-bit message, including start and stop bits, 5 data bits that can be recorded in one of two 5 bit registers selected by the AO bit. In response to the transmission of the message, the AA responds with a return message delayed by 5 clock cycles. The format of the return message is 9 bits, of which one start, one stop (stop bit - log. "0") and 7 information. The return message contains information from one of the 7 bits of the AA registers, for example, which is indicated in the AO category of the direct message. Thus, in two exchange cycles from BCC to AA, 10 bits of information can be transmitted, from AA to BCC-14 bits.

The AR and AC contain 16 eight-bit receive registers, information in any of which can be recorded using a format message. In response, the AA will send to the BCC the contents of that of 16 seven-bit registers, the number of which is indicated in the AO - AZ bits of the direct message.

The subscriber module (MA) 5 is designed to transmit and receive voice and seal command information for three subscribers. MA consists of three identical channels. The coded speech signal through the speech switch 14 is fed to one input of the compaction device 15. At the other inputs of the compaction device 15 are received commands in serial format and the signal "Interruption". The number of the selected speech signal is set by the control word in Pg control 16, recorded in it by a micro-computer. The sealing device 15 generates a compressed signal, which through the driver 17 controls the operation of the light emitting diode 18. The radiation of the LED 18 is introduced into the fiber and is transmitted to AA.

The response signal from AA is fed to the receiving photodiode 19, amplified by the amplifier 20, and then the electrical signal is supplied to the decompression device 21. At the output of the decompression device 21, a digital speech signal and command information in a serial format are generated, which are received on a common bus, as well as service signals the presence of an optical signal from AA and the onset of stable cyclic synchronization. These signals are accessible by the microcomputer via the status register.

The clock generator module 4 contains a crystal oscillator that sets the clock frequency and generates all the clock signals required for the operation of the MA compaction devices, as well as the delta, encoding of the codecs of the ringing module 6, the conference communication module 7, and the GHS interface module 8.

The GHS 8 interface module converts a digital signal into an analog one, and vice versa, it interfaces with a wired line, receives a call signal from a GHS, simulates the dialer and monitors the Busy, Free, and Station Answer signals.

Analysis of incoming signals and dialing control takes place under the control of the program in micro-computers. The subscriber’s device works as follows. The signal from the photodiode "" is amplified by an amplifier 24 and fed to a synchronization device 26, which produces a decompression of the received signals. Further, the speech coded information is supplied to the delta encoder 27, from the output of which the speech analog signal through the amplifier 29 is supplied either to the telephone 31 of the handset or to its loudspeaker (when making a tone call). The direction of signal flow to the telephone or loudspeaker is set by the signal from the exchange circuit 33. The decompressed command information is transmitted to the exchange circuit, where it is converted into a parallel format and stored in storage registers.

In the AR, information in the storage registers is displayed on the indicating device 34. The speech signal from the microphone 32 is amplified by the amplifier 30 and encoded by the delta encoder 28. A digital signal from the delta encoder simultaneously with the signal from the exchange circuit 33 containing information on the status of the control elements 35 is received to the LED 23 through the amplifier 25 and is emitted into the LED.

AA controls are the handset lever, 31 numeric keys (numbers 0 to 9), two service buttons “Reset” and “Repeat”. Power supply AA, AR and AC is carried out from an alternating current network of 220 V 50 Hz through a power supply unit 36 of the BP2-3 type from a microcalculator of the type B3-21.

As optical communication lines, cables with a quartz-quartz fiber with a core diameter of 50 μm are used. Superluminescent LEDs were used as emitters, silicon p-i-n photodiodes were used as receivers. Shapers for LEDs - on a logic transistor, photodiode signal amplifiers without AGC on three bipolar transistors.

Light and photodiodes are installed in connectors such as a fiber-optic cable-device, amplifiers and drivers are located in the immediate vicinity of the connectors and are shielded. The power introduced into the fiber at the maximum amplifier gain is sufficient to ensure reliable communication at a distance of up to 300 m with a channel error probability of less than 10 ^-7 .

The inventive system provides subscribers with the following types of services.

For the subscriber’s device:

- selective communication with any subscriber of the system;

- keypad dialing;

- participation in a conference call organized with the AR;

- sound signaling of a call signal from the AP during selective communication with any other subscriber;

- automatic repeat call busy subscriber.

For the head office:

- selective communication with any subscriber of the system,

- keypad dialing;

- Organization of an unmatched conference call with the number of participants up to 8;

- receiving incoming calls from the city telephone network;

- organization of communication with subscribers of the city telephone network;

- abbreviated dialing of the GTS number;

- GTS numbers memory for 99 11-bit numbers;

- automatic dialing of the number of a busy GTS subscriber;

- memory of the conference participants (up to 10 different combinations);

- light signaling of the called and calling subscriber;

- light indication of the dialed number of the GTS subscriber;

- holding the previous communication mode in order to establish a new connection with the possibility of returning to the held mode, etc.

If the switch on the AP is in the “Secretary” position, the aircraft has all of the above options, except for loud-speaking communications. Otherwise, the functionality of the speakers is the same as that of AA.

Claims (1)

A fiber-optic intra-ship communication system containing a switching subsystem, connected via tract-forming devices with N subscriber terminals, to a control device and to a signal-calling device, characterized in that the switching subsystem is made in a modular manner in structure with a common system bus in the form of a central switching unit ( BCC) with a control microcomputer based on a microprocessor of the type КР580 ВМ80, in addition to the switching subsystem, a clock generator module, subscriber modules, a conference communication module, an interface module with city telephone exchanges, the signal-calling device made in the form of a ringing module, tract-forming devices made in the form of bus shapers, the microcomputer contains a central processor and a control signal buffer, while the subscriber module consists of three identical channels, each of which contains a voice switch connected through a compaction device to a signal conditioner with a transmitting LED, and also through a bus connected to the device loosely signal conditioning with a receiving photodiode, and the receiving part of the subscriber terminal consists of a photodiode connected in series with a signal amplifier, a synchronization device, a decoder, a signal amplifier and headphones, and the transmitting part contains an LED connected in series with an amplifier, a synchronization device, an encoder, an amplifier and a microphone, while the synchronization device is connected to the exchange circuit, which, in turn, is connected to the display device and the device CONTROL information on the state government.

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