Hardware manual

Issue 8 Electra Elite
5 - 78 Installing Electronic Telephone Units
5.4 SLI(4)/(8)-U( ) ETU
5.4.1 Description
The SLI(4)/(8)-U( ) ETU is the interface for Single Line
Telephones and for analog voice mail units. It has a
built-in ringing generator (RSG) and supports Single Line
Telephones or analog Voice Mail ports.
This ETU also provides circuitry for loop status detection,
talk battery, sending ringing signals, message waiting,
and loop disconnect for dial pulse signal detection.
The PBR circuit in the CPUB( )-U( ) ETU or PBR( )-U( )
ETU is required with Voice Mail or DTMF Single Line
Telephones.
Figure 5-44 SLI(8)-U( ) ETU