User's Manual

Table Of Contents
DRAFT 4
TB9400 Installation and Operation Manual Description 21
© Tait Electronics Limited September 2011
1.7.1 Signal Paths
Figure 1.6 gives an overview of signal paths within the reciter.
Digital P25 signals from the receive RF interface pass through the digital
receiver and P25 modem to the control software in the RISC processor. The
control software passes the signal through the Ethernet interface to the site
controller, or to the central voter in a simulcast system.
Input to the Ethernet interface can be from the site controller, or from the
central voter in a simulcast system. These inputs are processed by the RISC
and passed through the P25 modem to the transmitter. If the base station is
itself a central voter, this input can also be a received signal, which is voted
on and sent back through the Ethernet interface to the site controller.
1.7.2 Online and Offline Modes
The base station normally operates in Online mode, but you can put it into
Offline mode via its web interface.
Online Mode In Online mode, the base station performs its normal functions.
Offline Mode When you program the base station or run invasive diagnostic tests, the base
station must be in Offline mode. This takes the base station out of service.
However, the front panel is still operational and can be used in the normal
way.
Figure 1.6 Reciter signal paths
Modulator
Demodulator
P25
Modem
Cartesian
Loop
Control
ADC
ADC
DDC
DAC
RTP
UDP
IP
Transmit
RF Interface
Transmit
RF Interface
(feedback
from PA)
Receive
RF Interface
Ethernet
Interface
Protocol
Stack
Reciter Control Board