Polycom EF2201 Brochure & Specs page 29

Line Inputs
The line inputs to the matrix are typically inputs from video codec signals or program audio devices such as VCRs or DVDs. In a
typical application these signals must be heard in the local room and can be mapped through the matrix to outputs.
Outputs
The outputs of the matrix are 12 line outputs (1-8, A-D), the two echo canceller references, and the four EF Bus signals W, X, Y, and
Z for a total of 18 outputs. The echo canceller references are not physical outputs of the device, but are used internally. You do
not need to use an output for the echo canceller reference. This is all shown in Figure 14.
Outputs 1-8 (Vortex EF2280)
Outputs 1-8 can contains any combinations of inputs. The default mappings in most of the 16 factory presets configure outputs 1-8
as direct outputs of inputs 1-8.
Outputs A-D
The A-D outputs are typically connected to amplifiers, video codecs, and recorders. Typically this audio is comprised of the local
microphones, the codec, and the phone add signals.
EF Bus
This is a high-speed digital bus that appears at every Vortex networked together. This bus allows signals placed on the bus from
one device to appear at all the other networked devices, except the sending device. The Vortex EF2280 supports placing 4 signals
on this EF bus: the W, X, Y, and Z expansion signals. All four bus channels, W, X, Y, and Z, can be used in the same way since they
all carry information about the number of open microphones.
P-bus.
This bus is the default bus for sending the telephone signals to other devices. Only Vortex devices that have an integrated
telephony interface can put signals onto the P bus, but all devices can take signals from the P bus.
W-bus.
This bus is the default bus for sending the microphone signals to other devices. In addition to the signal data this bus sends
information about how many open microphones there are in the sum of the microphones that are mapped to the W bus output.
X-bus.
This bus is the same as the W-bus and is used for sharing microphones with other devices. This bus sends information about how
many open microphones there are in the sum of the microphones that are mapped to the X bus output.
Y-bus.
This bus can be used for sending any signal between different devices. This bus also can be used for sharing microphone
information. Typically applications may be for sending stereo program audio between devices (one channel on the Y-bus and one
channel on the Z-bus).
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