AS3170 - Hotline 10
The Hotline 10 unit provides a method of connecting up to ten remote telephones back to a single central control telephone with instant calling being created by lifting the telephone off-hook and selecting the active line key.
Outgoing calls are made in the same manner with the additional facility to conference all active calls.
All remote devices are presented to the local unit as 4W E&M on RJ45 connectors but can be connected to FXS, FXO or AC15 circuits with the use of external interface adaptors.
Lamps and keys are provided on the base console to allow calling to the remote telephones and also indicate the remote telephone status including an ALL CALLS button to alert all external parties in the event of an emergency.
The functional diagram below shows two operational modes, one with the telephone interface equipment locally for operating over two wire lines and the other where a mux is used to distribute the hotline handsets to remote locations over a private closed network.