Hardware manual

Electra Elite Issue 8
System Hardware Manual 5 - 35
4.5 COIB(4)-U20/U30 ETU
4.5.1 Description
This ETU can function the same as the COI(4)-U
( ) or
COID(4)-U
( ) ETU to provide Central Office Interface.
Transmit and receive pad controls have been added to
the COIB(4)-U20 ETU. Only the COIB(4)-U30 ETU can
support the CO Message Waiting Indication Feature
(S9500). Ground Start trunks are not supported. When
the ETU is set for COID mode, Loop Start trunks and
Caller ID trunks are supported. Caller ID does not work in
the COI mode. Fax CO Branch support is provided on
the COIB(4)-U20 port 4 only.
This ETU contains circuitry for outside ring detection,
holding, dialing, and control functions.
This ETU can provide a CAMA trunk for E911.
CAMA trunk support is provided on COIB(4)-U20 port 3.
When functioning as a COI(4)-U( ) or COID(4)-U( ) ETU
only DTMF signaling is supported. Tip and Ring electrical
fuses are provided to comply with UL 1459 requirements.
Refer to Figure 5-20 COIB(4)-U20/U30 ETU.