Tait P25 CG, Installation And Operation Manual

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18 Description TB9100/P25 CG Installation and Operation Manual
© Tait Electronics Limited January 2007
1.7 Theory of Operation
The reciter receives RF signals from its RF input and sends RF from its RF
output to the PA, along with a PA key signal. The reciter also receives signals
from and sends signals to the analog line, the Ethernet interface, and the
control panel (see
Figure 1.2 ).
A system control bus interconnects the modules and carries alarm and
control signaling between the reciter and the other modules.
The control panel speaker and microphone enable the base station
maintainer to communicate with the dispatcher or with subscriber unit
radios. The Ethernet interface carries voice over IP as well as
communications with the CSS.
The reciter carries out signal processing and has overall control of the base
station. It comprises an RF, a digital, and a network board, as shown in
Figure 1.3 .
Figure 1.2 Base station high-level diagram
Reciter PMU PA
RF To
Antenna
RF From
Antenna External Reference
Frequency (if used)
AC I/P
DC I/P
28VDC
(high current)
System Control Bus
Microphone
I/P
Network
Speaker
O/P
RF +
PA Key
28VDC (low current)
Analog Line
(4-wire E&M)
Ethernet
Interface
RS-232 +
Digital I/O
Control
Panel