Mircom TX3 Series - Figure 19 Multiple Lobby Control Units to Multiple Lines

42 (119) Telephone Access System Installation and Operation Manual Version 3.7
LT-969 Copyright January 2017
TX3 System
Lobby Control Units 1, 2 and 3 can make simultaneous calls as long as a line is not
in use by another Lobby Control Unit. For example, if Lobby Control Unit 1 uses
line1, Lobby Control Unit 2 can use Line 2 and Lobby Control Unit 3 can use
line 3.
When Lobby Control Unit 1 is using line 1 and Lobby Control Unit 2 also wants
to use line1, which is busy, then a line busy message displays on Lobby Control
Unit 2.
Figure 19. Multiple Lobby Control Units to Multiple Lines
1 2 3
4 5 6
7 8 9

* 0 # i
1 2 3
4 5 6
7 8 9

* 0 # i
1 2 3
4 5 6
7 8 9

* 0 # i
NSL
Control
Unit
NSL
Control
Unit
Line1
Line2
Line3
Telephone outlet
Central office line
RS-485
bus
RS-485 from
previous unit
RS-485 to
next unit
Lobby
control
unit 1
Lobby
control
unit 2
Lobby
control
unit 3
T/R
T/R
T/R