Mircom TX3-2000-8U-C - Dual Lobby Control Units; Figure 13 Dual Lobby Control Units

32 TX3 Telephone Access System Installation and Operation Manual
TX3 System
3.3 Dual Lobby Control Units
Figure 13 shows a dual entry application for either an NSL type or ADC
connection type. The phone line from either the NSL control unit or an ADC
dedicated phone line is shared by both Lobby Control Units.
The Lobby Control Unit senses whether the line in use. If one of the Lobby
Control Units is in use and the user tries to make a call, the other lobby indicates
that the line is in use.
The RS-485 network connection is optional and is only required if the user
decides to connect a PC configurator on one of the panels to configure and/or
monitor both systems.
Figure 13. Dual Lobby Control Units
Line1
NSL
Control
Unit
1 2 3
4 5 6
7 8 9

* 0 # i
T/R
Line1
Telephone outlet
Central office line
1 2 3
4 5 6
7 8 9

* 0 # i
1 2 3
4 5 6
7 8 9

* 0 # i
Line1
1 2 3
4 5 6
7 8 9

* 0 # i
Line1
OR
RS-485 bus
(optional)
RS-485 bus
(optional)
Lobby
control
unit 1
Lobby
control
unit 2
Lobby
control
unit 1
Lobby
control
unit 2