Instruction manual

ACU-1000 Operations Manual
Interoperability Now 1-17
1.7.3 NXU-2A
The NXU-2A Network Extension Unit is a separate product. It interfaces many types of
communications devices (such as radios or dispatch terminals) to an IP-based network. The
NXU-2A provides a RoIP link, which includes radio control signals (PTT, COR, RS-232)
along with a VoIP audio path. A variety of vocoders can be configured; this allows the VoIP
linked to be optimized based on its purpose and the bandwidth available. The NXU-2A is
designed to operate over TCP/IP networks in conjunction with standard networking equipment-
switches, hubs, routers etc.
Figure 1-9 shows a simple NXU-2A application were the unit is basically acting as a “cable
extender” allowing the audio console to operate the radio with the radio located anywhere on
the network. The audio console sends TX audio and a PTT signal to the radio, and the radio
sends a COR (unsquelched indication) as well as RX audio back to the console. The NXU-2As
can also pass RS-232 to control radio functions such as frequency or power level. Once the
network connection between the NXU-2As is created, it remains in place until intentionally
dissolved. When the console & radio are both idle (no audio being streamed across the
network) the connection uses minimal bandwidth (an occasional “keep alive” data packet is
exchanged to maintain the connection).
NXU
Four Wire
Audio Console
Network
RADIO
NXU
Figure 1-9 NXU-2A As Cable Extender
A similar use for the NXU-2A is to remotely connect a radio or other device (such as a four-
wire audio console) to the ACU system as shown in Figure 1-10. Both configurations can be
set up as a permanent connection, or the network connections can be controlled using the
WAIS Controller software.
Figure 1-10 NXU-2A as ACU-1000 DSP Module Network Interface
Network
RADIO
NXU
ACU-1000
`DSP