Remote Subscriber - ABB ETL600 Instruction Manual

ETL600
and output speech levels and ringer frequency are programmable. In
order to improve the signal to noise ratio by up to 10 dB on noisy links,
a compander function can be enabled.
As long as the hot line is idle (both phones on hook), the service
phone may utilize the speech channel. In any case, the direct phone
has priority over the service phone.
3.4.1.2.

Remote subscriber

Subscriber
Fig. 3-27
In this application, the ETL-link is inserted in the 2-wire loop between a
subscriber phone and a PAX as shown in Fig. 3-27. The subscriber
side of the link has to be programmed for operation mode 'Remote
subscriber', while operation mode 'PAX 2-wire' has to be selected for
the PAX side of the link. The speech levels from and to PAX and
subscriber are programmable as well as the frequency of the ringing
tone on the subscriber side. Both tone (DTMF and MFC) or pulse
signaling are supported.
Alternatively, if the PAX allows connection of a remote subscriber over
4 wires with E&M-signaling, the PAX side terminal of the link can be
programmed for operation mode '4-wire'. This mode of operation –
shown in Fig. 3-28 – is to be preferred to that one shown in Fig. 3-27
as it has only one 2-wire section instead of two. The number of hybrids
is reduced and so echo cancellation can be improved. For further
functions available on the PAX side, refer to the following section.
Subscriber
Fig. 3-28
For the PAX connections described above, the compander can be
enabled. The compander improves the signal to noise ratio by up to
10 dB on a noisy link.
As long as the subscriber loop is idle, the service phone may utilize the
speech channel. In any case, the subscriber loop has priority over the
service phone.
Structure and Function
1KHW001489-EN
ETL600
O4LE
a/b
2-wire remote subscriber
ETL600
O4LE
a/b
4-wire remote subscriber
ABB Switzerland Ltd
ETL600
O4LE
ETL600
E&M, PAX Blocking
O4LE
November 2005
a/b
PAX
Local/Transit
4
PAX
3-39