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DSL272 is new generation of multichannel PCM multiplex device designed for use in the existing telephone network.
DSL272 system allows the unobstructed full duplex voice and data, through up to four channels with analogue access using one conventional subscriber (copper) line.
The signal bit rate through every channel is 64 Kbit/s.
The system consists of two parts: the remote terminal (on subscriber's side) DSL272-K and the central office terminal DSL272-TC. The remote terminal can be installed internally and externally.
On the subscriber's side, it is possible to connect up to four telephone sets with pulse or DTMF dialing, fax devices or data modems. On the central office side (DSL272-TC) it is possible to connect analogue telephone exchange or Z-interface of digital telephone exchange.


Twelve central office terminals DSL272-TC are being installed in one rack with a common control unit.

The system DSL272 basically contains only two modules:
DSL272-K (on the subscriber's side) and DSL272TC (on the telephone exchange side). Without any additional setting the system can be easily installed, maintained and supervised.

Each module of the system functiones as a separate unit, meaning that each unit in one rack works independently.

One existing copper line allows connection of four subscribers with the full service from the telephone exchange. Remote power supply excludes the use of additional power supply systems on the subscribe's side.

DSL272 is appropriate for data transfer because it allows speed of 33.6 kbit/s when there is one A/D - D/A transmission. When the number of transmission is more than one, the speed of transmission decrease in range from 26.4 kbit/s to 31.2 kbit/s.


Remote terminal DSL272-K 235mm x 220mm x 58mm
Central office terminal DSL272-TC 262mm x 225mm x 30mm


Line systems between the remote terminal and central office terminal

Line code 2B1Q in accordance with ETR 152
Line speed 272kbit/s
Maximum reachable distance 3.4km d = 0.4mm (Cu)
Maximum reachable distance 6.5km d = 0.6mm (Cu)
Remote power supply ± 75V; 50mA

DSL-KRemote unit DSL272-K

PCM A-law according ITU-T G.711
Impedance 600Ohm
Current 28 ± 2mA
Line voltage 24V
Loop resistance 350Ohm
Ringing voltage 43Veff / 25Hz
Metering pulses 16/12 kHz
Receive level 0dBr
Transmit level -7dBr
Idle channel noise -67dBm0p
Working temperature range From -40°C TO +70°C

DSL-TCCentral office terminal DSL272-TC

PCM A-law according ITU-T G.711
Impedance 600Ohm
Current 15mA - 60mA
Ring voltage detection min 20Veff
Ring detector impedance 2.5kW +1mF
Metering pulses detector 16 kHz; >1.2Veff
Receive level -3dBr
Transmission level -4dBr
Dialing Pulse or DTMF
Consumption 13W
Range of temperature from -5°C TO +40°C