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CODES SPECIFICATIONS QUANTITY

DL 2156D2 BASIC DIGITAL TELEPHONE EXCHANGE

didactic equipment This system shall be composed of the basic digital telephone exchange system and the central office

simulator.

The telephone switching system shall be composed of the following sections:

- Line from analogue private phone

- Line from analogue telephone exchange system

Main features of the trainer:

PCM switching matrix, space-time-space

Flash stored control program

2 PCM frames, 30 channels each

Analysis and generation of the signalling associated through DSP

Signalling control for each single channel in real time

With this trainer it must be possible to perform the following exercises:

With the line from analogue private phone it will be possible to study:

- The conversion from four to two wires

- The call current

- The hook circuit

- The tone select ion

- The multi-frequency selection

- The over voice signalling

With the line from analogue telephone exchange system it will be possible to study:

- The decoding of the state of the line

- The decoding of the selected number

- The line signalling tone generation

- The call identification signallingThis basic digital telephone exchange trainer shall permit the study of the function of a telephone exchange thanks to a three

sections system that compose this panel.

The first section will correspond to a block diagram that will simulate the digital and the analogue networks with test points.

The second section will correspond to socket interface with test points and the third section will include a telephone exchange

window.

The interface section shall be divided in different signal sockets and sockets for the connection of the telephones in terms of

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CODES SPECIFICATIONS QUANTITY

main board, analogue telephone and local trunk line.

In particular, the main board section will include the telephone exchange unit with the related boards that will be protected by

a transparent plastic front window; the second section will have the electrical scheme shown on the from panel and the third

section will include supply sockets, no. 8 of RJ11 type and no.45 test points plus a plastic cover for the fault simulator port.

For control telephones it must be possible to connect the telephone exchange station to 4 sockets and for the analogue

telephones it will must be possible the connection to 4 sockets .

The main boards described above shall include the following type of signals:

- frame signal

- output voice and data channels signals

- input voice and data channels signals

- clock signal at 4,096MHz

-exchange data signal between the SD board ant the CPU

-power supply voltage at 5 Volt of the telephone exchange

-synchronism signal for the generation of the call current

-signal of internal alarm for hardware problems

-exchange data signal between the CPU and the DSP

The analog section signals shall describe the bushes in the following blocks: CO trunk line-BCA1-BCA2 and BCA3.

For BCA1 block, when the receiver is lift it must be possible to see the analogue signal of the voice or the multi-frequency

selection.

More in detail, this block shall have the following kind of signals:

-data signal for the specific telephone at the socket BC1

-signal representing the state of the hook for the bca telephone of BC1 socket

- signal that will enable sending the call current for the socket BC1

-output voice signal

- frame signal of the PCM channels- PCM flow signal in upload

For BCA2 and BCA3 sections must be included the following signals:

- signal of control for emergency relay

- data out signal for the interface

The central office section signals will reproduce the signals of the local line and these terminal