Introduction ~ Networking 7

Technical Services Group ~ 1-800-283-5936 (USA) ~ 1-801-974-3760
Networking

The latency or propagation

delay is <1ms.

✍✍
Expansion bus
The digital mix-minus expansion bus (RJ-45 LAN) is used to connect up to eight
XAP 800/400s and 16 XAP TH2 units,where the total number of microphone inputs
does not exceed 64.The maximum distance between interconnected XAP 800/400 or
PSR1212 units is 80 feet (24 meters).Connecting a XAP TH2 must not increase the
cable length between two PSR1212s,XAP 800s and/or XAP 400s beyond 80 feet.
ClearOne recommends that category five twisted-pair (10BaseT LAN) cable be used.
The expansion bus (E-bus) allows audio routing between destinations on the
E-bus network.The E-bus contains 12 independent digital audio buses labeled O–Z
which can route mic or line level inputs in any combination across the E-bus
network.The O–Z buses are divided into two groups (O–R and S–Z) based on their
capabilities and default settings.The E-bus also contains four PA adapt/acoustic
echo cancellation reference buses,four global gating buses, and one control bus.
•O–R buses.These four audio buses are defaulted as the mic mix buses;they
can communicate the NOM count and mic mixing parameters across the
network to other XAP 800s.All gated mics are routed to the 0 bus by default.
•S–Z buses.These eight buses are defaulted as auxiliary mix buses.They are
used to route auxiliary audio,such as from a CD player or VCR,to and from
other units on the network.These buses are also used as mic mix buses when
NOM count is not required.
•PA Adapt/Acoustic Echo Cancellation Reference buses.These buses
allow an input from a XAP 800 to reference an output on another linked
XAP 400/800.See PA Adapt and AEC Reference on page 33 for more
information.
•Global Gating Groups A–D buses.These mix-minus buses are defined as
microphone gating groups which support first-mic priority,maximum number
of mics,etc. and work across all linked XAP 400/800s.Unlike the audio
buses,they contain only mic status and gate parameters. See page 41 for
more information about gating groups.
•Control bus.The control bus is an independent channel from the E-bus’s
audio channel;it uses a different pair of wires on the same E-bus cable.This
allows control information to pass even if the units are not using the audio
link.The XAP 800 supports the full set of commands through the control bus.