Hardware manual

Issue 8 Electra Elite
5 - 32 Installing Electronic Telephone Units
4.4 COIB(4)-U10 ETU
4.4.1 Description
This ETU can function the same as the COI(4)-U( ) or
COID(4)-U( ) ETU to provide Central Office Interface.
When the ETU is set for COID mode, Loop Start trunks
and/or Caller ID trunks are supported. When the ETU is
set for COI mode, Loop Start or Ground Start is
supported. Caller ID is not supported in the COI mode.
Connections for Ground Start Trunks are polarity
sensitive.
This ETU contains circuitry for outside ring detection,
holding, dialing, and control functions. It can also
provide a CAMA trunk for E911.
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 5-18 COIB(4)-U10 ETU.
Figure 5-18 COIB(4)-U10 ETU