Tait TB7300, Инструкция по установке и эксплуатации

Страница: 65 / 89

TB7300 Installation and Operation Manual Installation 65
© Tait Limited November 2016
5.6.4 Connecting an External Frequency Reference
An external reference frequency is not normally required for B band.
However, an external reference can be used when you need to maximize
the range of the base station. The external reference frequency can be
10MHz or 12.8MHz, with an input level of 300mV
pp
to 5V
pp
. The
stability of this reference should be better than 100 parts per billion. The
base station automatically detects the frequency of the external reference
and configures itself accordingly.
If an external reference is required, enable the external reference “Absent”
alarm (Configure > Alarms > Control).
Use a 50
Ω
coaxial cable (RG58 or RG223) to connect the external
reference to the base station’s external reference frequency input. You can
daisy-chain up to eight base stations using T-junctions. The maximum
overall cable length is 30m. Terminate the last connection (including single
base stations) with a 50
Ω
load.
5.6.5 Ethernet Connection
The RJ-45 socket on the reciter’s rear panel provides the 1-BASE-T or
100BASE-T Ethernet connection to the other devices in the network. Use
a Cat-5 cable to connect this socket to the Tait Network via a router or
switch.
The Web UI allows you to set the Ethernet port speed auto-negotiation to
10/100 Mbit/s or to negotiate a maximum 10 Mbit/s. Tait recommends that
you keep the port speed at the factory default setting of 10 Mbit/s. The
reciter hardware and software are scaled to meet the performance
requirements of processing multiple voice streams along with supervisory
control and management communications. 10 Mbit/s is ample for those
requirements. The 10/100 Mbit/s setting is provided for compatibility
reasons, but it is possible under high traffic conditions at 100 Mbit/s for
Figure 5.5 Daisy-chaining an external frequency reference input
50
Ω
termination
(also needed for
single base stations)
maximum of eight base
station loads on one
frequency reference output
maximum overall cable
length is 30m