Module Description; Af Interface O4Le - ABB ETL600 Instruction Manual

ABB Switzerland Ltd
3.3.

Module description

3.3.1.

AF interface O4LE

The AF interface board O4LE is a universal interface for audio
frequency signals. It supports the applications:
•
Telephony,
•
Teleoperation,
•
External teleprotection.
These are the analog services described in section 3.4.
The unit is fully programmable via user interface program HMI600.
The hardware of one O4LE board can carry the telephony service for
one AF-channel. The teleoperation and external teleprotection ports
can be assigned to at most two AF-channels, either channels 1 and 2,
channels 2 and 3 or channels 1 and 3. When telephony is configured,
one of these two channels must be the channel carrying the telephony
service.
Up to four digital filters can be configured on one O4LE board. These
can be transit filters for through-connection of AF-signals in transit
stations. When an O4LE board carries telephony functions, only two
transit filters are available on that board, as two filters are required for
speech filtering.
The board houses a digital signal processor (DSP) and associated
peripheral circuits. The hardware comprises the following ports:
•
Four 4-wire 600 Ohm AF ports AF1 to AF4. Port AF1 is also used
for 4-wire telephony.
•
One 2-wire telephone port subscriber side (FXS). This port is also
used for the service phone (socket at front plate). At any time, only
one of the two ports is active. This is controlled by a switchover
relay.
•
One 2-wire telephone port office side (FXO),
•
E&M telephone signaling ports,
•
Telephone hybrid local/transit input port,
•
External teleprotection boost input port,
•
Relay with switchover contact for signaling the availability of the
telephone channel,
•
TDM bus port for internal communication with the P4LT board.
A buzzer on the board is activated to announce an incoming service
phone call even if no service phone is plugged.
3-18
1KHW001489-EN
November 2005
ETL600
Structure and Function