OPU-1
UNIVERSAL POWER-LINE CARRIER SYSTEM TYPE OPU-1
GENERAL DESCRIPTION - Rev 7 (May 2019)
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2.5
ANALOG OPTIONAL MODULES
When working with analog channels, the OPU-1 terminal can contain up to five optional
modules. The following sections detail the large variety of options available.
2.5.1
Speech module
For a speech-plus service (T-type channel), the OPU-1 terminal must have a speech
module.
The TDPU.20 speech module is a compact module with all the circuits required to operate
as: 4-wire termination, 2-wire termination, exchange-side 2-wire termination, and subscriber
termination.
No plug-in submodules are needed
.
The TDPU.20 module is compatible with previous TDPU modules. The external connection
is also compatible.
The TDPU.20 module contains the speech-band transmit and receive filters, the upper
frequency of which can be defined from the management terminal, the dynamic
compressor/expander, a 4-wire configurable termination and a subscriber-side 2-wire
telephone termination.
The 4-wire configurable termination can be dynamically switched between 4W/2W
operation by means of an external command. This termination can be configured as an
exchange-side 2-wire termination, carrying out the required telephone-converter tasks.
The subscriber-side 2-wire telephone termination comprises the telephone hybrid, the
subscriber circuits and the ring-current generator. This termination supports up to two
telephones in parallel.
The TDPU.20 speech module also contains the circuits needed to receive the external input
of the M wire (transmission call) and for signalling the E wire (reception call).
