Clear-Com BS850 (Last time buy) - Manual (Page 33)

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Cascading Multiple Base Stations
Two or three base stations may be cascaded to effectively increase the number of available receivers without
increasing the number of base transmitters. Cascaded bases behave like a single base with up to twelve receivers.
In a cascaded system, one base is configured as the Master and the additional bases as Slaves. Only the
transmitters in the Master are used. Any transmitters present in the Slaves need to be disabled to prevent
interference with this or other systems. Because only the Master transmitters are used, receiver audio from the
Slaves must be distributed to the Master for retransmission to other Beltpacs. A data cable connected between
the Master and Slaves allows audio routing requests and status to be communicated.
The PRO850 supports two methods of distributing audio from the Slaves to the Master. These are called “Aux
Distributed” and “2-Wire Distributed”. Each approach has its own advantages and disadvantages. For a quick
temporary setup where not all features are required, “Aux Distributed” is the simplest choice. In a permanent
installation where most features are needed, “2-Wire Distributed” is the preferred method.
Common Configuration
Some aspects of a cascaded base system are common to both types of audio distribution. These include the
data cable connection and parts of the system configuration. Connect a data cable from the external control
connector of the Master to the Slaves (see wiring diagram on page 9). If there is only one Slave, a standard
Ethernet crossover cable may be used to connect the Master to Slave1. Note that the external port is an
RS422 serial connection not Ethernet. For this reason, an Ethernet hub cannot be used. It is important that
the correct number of Slaves be specified in the Master configuration. If this number is incorrect, the
system may not function correctly or may have degraded response times.
If a PC is going to be used for configuration, connect it to the Master base station. All Slave base settings
are accessible through the Master.
Once the connections are made, configure the receivers on each base and save the settings separately on
each base station. Then configure the transmitter and Beltpac settings at the Master base. Be sure to disable
the transmitters in the Slave(s) by turning them off in the Tx Power screen (see page 25). Do not make
Beltpac configuration changes at the Slaves, as they will be overwritten by the settings from the Master.
Once all settings are complete, save them again and upload them to the Beltpacs (from the Master base).
Then synchronize the settings from the Master (see page 18) and save the settings at the Slaves.
If paging will be used, connect the page outputs of each base to separate inputs on the paging amplifier and
connect page relays in series or parallel as required. If only Beltpacs on a single base will be allowed to
page, it is only necessary to connect that base to the paging amplifier.
Aux Distributed Set Up
The Aux Distributed configuration is simpler than 2-Wire Distributed, but has more feature limitations.
ISO+ is not supported in an Aux Distributed configuration. Also, there are restrictions on simultaneous
conversations from multiple Beltpacs. For instance, if one Beltpac user on a Slave base is currently talking
on intercom channel 1, other users on Slave bases will be unable to talk on channel 2. They will be
restricted by the system until the first user finishes. However, they may join in on the conversation on
channel 1 or listen to channel 2 without restriction. These restrictions are because only a single audio path
exists between the Slaves and the Master. Restrictions are enforced automatically by the system. A user
attempting to talk on a restricted channel will hear a busy tone upon pressing the Beltpac button.
To set up the system for Aux Distributed operation, configure one base as Mstr: Aux Dist n Slave(s) (see page 13)
and select correct number of Slaves (one or two). Then configure one Slave base as Slave1: Aux Dist. If there
is a second base, configure it as Slave2: Aux Dist. Note that there can only be one Slave1 and one Slave2.
Connect an audio cable from the auxiliary input of the Master base to the auxiliary output of Slave1. If Slave2
is present, connect an audio cable from the auxiliary input of Slave1 to the auxiliary output of Slave2.