Clear-Com BS850 (Last time buy) - Manual (Page 18)

15
2-Wire Distributed Set Up
When a system is configured for 2-Wire Distributed operation, it has most of the features of a stand-
alone base. However, the wiring is somewhat more complex and there are still some feature
limitations. In this mode, receiver audio from the Slave bases is distributed by way of the Auxiliary
inputs and outputs as well as the 2-wire intercom lines. This means that the Auxiliary inputs and
outputs cannot be used for other purposes. Since these inputs and outputs are not available, ISO+
operates differently in this configuration. Only the Master is configured for Mstr: 2-Wire ISO+ 1 Slave
or Mstr: 2-Wire ISO+ 2 slvs. The Slaves are left as Slave1 (2): 2-Wire. As soon as the Master is set
for this mode, the local headset switches and LED’s are disabled and the Aux wired status LED lights.
An external 4-wire interface (with appropriate levels) can then be connected to the front panel headset
connector. The headset amplifier and microphone preamp are still used. Therefore, the audio levels
may need to be matched to the 4-wire line through external devices.
To set the system up for 2-Wire Distributed operation, configure the Master base as either Mstr: 2-
Wire or Mstr: 2-Wire ISO+ (with the appropriate number of Slaves). Then configure the Slaves as
Slave1 (2): 2-Wire. NOTE: Be sure to save settings separately on the Master and Slave bases.
Connect audio cables to the Auxiliary inputs and outputs as described for Aux Distributed set up.
Connect 2-wire lines between the bases as needed. Two lines are required if Clear-Com lines are used,
but only one is needed for RTS. If the system is to be connected to a hardwired intercom system
through the 2-wire interface, do that as well. Be sure that all bases are configured for the same type of
2-wire line (Clear-Com or RTS).
If no hardwired system is to be used or the hardwired system uses the 4-wire interfaces, it will be
necessary to terminate the 2-wire lines. External 200-Ohm terminators may be used or the line may
be terminated internally on the Master. To do this, remove the base station cover and move the
jumpers at JP4 and JP5 to short pins 1 and 2. Be sure to restore them to their original positions
before connecting the base to an existing 2-wire system. With a 4-wire system, it will also be
necessary to connect the 4-wire lines (outputs only) of the Slave bases to the intercom system.