JPS NXU-2B User manual

Interoperability Now!
INTEROPERABILITY NOW
Installation and Operation Manual
NXU-2B
Network Extension Unit
JPS Interoperability Solutions
5800 Departure Drive
Raleigh, NC 27616
919-790-1011
Email: [e-mail] / [e-mail]
www.jpsinterop.com
JPS P/N 5190-200200 Revision 1.5 August 2020

NXU-2B Operations Manual
ii
NOTICE
© 2020 JPS Interoperability Solutions. NXU and NXU-2B are trademarks of
JPS Interoperability Solutions, Inc.
JPS Interoperability Solutions reserves the right to make changes to the
equipment and specifications without prior notice.
CAUTION
Changes and modifications to this equipment not expressly approved by JPS
Interoperability Solutions could impair proper operation of the equipment and/or
could void user’s warranty.
JPS Interoperability Solutions
[phone]
[email protected]
supp[email protected]om
5800 Departure Drive
Raleigh, NC 27616

NXU-2B Operations Manual
iii Interoperability Now!
Table of Contents
1GENERAL INFORMATION........................................................................................................1-1
1.1 SCOPE......................................................................................................................................1-1
1.2 DESCRIPTION ..........................................................................................................................1-1
1.2.1 NXU General......................................................................................................................1-1
1.2.2 Advantages of NXU Technology ........................................................................................1-2
1.3 NETWORK DETAILS ................................................................................................................1-2
1.4 SPECIFICATIONS......................................................................................................................1-3
1.5 EQUIPMENT AND ACCESSORIES SUPPLIED.............................................................................1-4
1.6 OPTIONAL EQUIPMENT -NOT SUPPLIED ................................................................................1-4
1.7 DIFFERENCES BETWEEN THE NXU-2B AND THE NXU-2A....................................................1-5
1.8 NXU-2B OVERVIEW...............................................................................................................1-6
1.8.1 Important definitions:.........................................................................................................1-6
1.8.2 Configuration.....................................................................................................................1-7
1.8.3 Basic Applications and Operation.....................................................................................1-7
2INSTALLATION............................................................................................................................2-1
2.1 GENERAL ................................................................................................................................2-1
2.2 UNPACKING AND INSPECTION ................................................................................................2-1
2.3 RESHIPMENT OF EQUIPMENT..................................................................................................2-1
2.4 INSTALLATION OVERVIEW .....................................................................................................2-2
2.5 INSTALLATION CONSIDERATIONS ..........................................................................................2-3
2.5.1 Internal Jumper Configuration..........................................................................................2-4
2.5.2 E&M Return Selection .......................................................................................................2-5
2.6 POWER REQUIREMENTS..........................................................................................................2-5
2.7 INSTALLATION CHECKLIST.....................................................................................................2-5
2.8 REAR PANEL CONNECTORS....................................................................................................2-6
2.8.1 DC Input Connector, (+12 VDC INPUT)..........................................................................2-6
2.8.2 Connection to Radio or Other Four-Wire Device (AUDIO/CONTROL) ..........................2-6
2.8.3 Network Connection...........................................................................................................2-8
2.8.4 Serial Port Connection, (RS-232)......................................................................................2-8
3CONFIGURATION .......................................................................................................................3-1
3.1 GENERAL ................................................................................................................................3-1
3.2 CONFIGURATION DETAILS......................................................................................................3-1
3.3 CONFIGURATION VIA WEB BROWSER ....................................................................................3-2
3.3.1 Name ..................................................................................................................................3-2
3.3.2 IP Address and Subnet Mask..............................................................................................3-3
3.3.3 Gateway IP Address...........................................................................................................3-3
3.3.4 Unit is a (Client or Server).................................................................................................3-3
3.3.5 Remote IP and Remote Port (applicable only to Client units)...........................................3-3
3.3.6 VoIP Port ...........................................................................................................................3-3
3.3.7 Command Port...................................................................................................................3-4
3.3.8 Communications Mode.......................................................................................................3-4
3.3.9 Voice Compression.............................................................................................................3-5
3.3.10 VoIP QOS DSCP Value .....................................................................................................3-5
3.3.11 Serial Port Settings ............................................................................................................3-5
3.3.12 COR Sense (COR/VOX/VMR)............................................................................................3-5
3.3.13 VOX/VMR Sensitivity.........................................................................................................3-6

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3.3.14 VOX/VMR Hangtime......................................................................................................... 3-6
3.3.15 RX Input Level................................................................................................................... 3-6
3.3.16 RX Boost Mode.................................................................................................................. 3-6
3.3.17 RX Delay ........................................................................................................................... 3-7
3.3.18 TX Output Level ................................................................................................................ 3-7
3.3.19 TX Delay............................................................................................................................ 3-7
3.3.20 Duplex............................................................................................................................... 3-7
3.3.21 COR Priority..................................................................................................................... 3-7
3.3.22 COR Inhibit Time.............................................................................................................. 3-7
3.3.23 NXU-2B Dispatch Option ................................................................................................. 3-8
3.4 CONFIGURATION VIA SERIAL PORT....................................................................................... 3-9
3.4.1 Configuration Using an RS-232 Terminal Program......................................................... 3-9
3.4.2 Configuration Mode Command Set................................................................................... 3-9
3.4.3 Command Summary........................................................................................................ 3-10
3.4.4 Setting Unit IP Address................................................................................................... 3-12
3.4.5 Setting Unit Subnet Mask and Gateway Address............................................................ 3-12
3.4.6 Using DHCP to Assign IP Parameters........................................................................... 3-12
3.4.7 Setting VoIP Port (Optional) .......................................................................................... 3-12
3.4.8 Client/Server Selection.................................................................................................... 3-12
3.4.9 Serial Port Settings ......................................................................................................... 3-13
3.4.10 COR and VOX Settings ................................................................................................... 3-13
3.4.11 Duplex Setting................................................................................................................. 3-13
3.4.12 VOX Hang Time.............................................................................................................. 3-14
3.4.13 COR Inhibit Time............................................................................................................ 3-14
3.4.14 Voice Compression Settings............................................................................................ 3-14
3.4.15 Security Settings.............................................................................................................. 3-15
3.4.16 Ethernet MAC Address.................................................................................................... 3-15
3.4.17 Command Port ................................................................................................................ 3-15
3.4.18 RX Input Level................................................................................................................. 3-15
3.4.19 TX Output Level .............................................................................................................. 3-15
3.4.20 Input Level Boost +20db................................................................................................. 3-16
3.4.21 TX Delay.......................................................................................................................... 3-16
3.4.22 RX Delay ......................................................................................................................... 3-16
3.4.23 VMR................................................................................................................................. 3-16
3.4.24 VOX and VMR Sensitivity Adjustments........................................................................... 3-16
3.4.25 Restoring Factory Defaults............................................................................................. 3-16
3.5 COMMUNICATIONS MODE ................................................................................................... 3-17
3.5.1 Store Setup Changes with SAVE Command.................................................................... 3-18
4OPERATION................................................................................................................................. 4-1
4.1 GENERAL ............................................................................................................................... 4-1
4.2 FRONT PANEL INDICATORS ................................................................................................... 4-1
4.2.1 Power LED........................................................................................................................ 4-1
4.2.2 Link Active LED................................................................................................................ 4-1
4.2.3 Channel Active LED.......................................................................................................... 4-1
4.2.4 Audio Input LED............................................................................................................... 4-1
4.3 REAR PANEL CONNECTORS ................................................................................................... 4-1
4.4 NXU-2B OPERATION............................................................................................................. 4-1
4.4.1 Operation at Power-Up..................................................................................................... 4-2
4.4.2 Input/Output Audio Level Adjustments ............................................................................. 4-2
4.4.3 COR Input Description ..................................................................................................... 4-2

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4.4.4 RS-232 Serial Data ............................................................................................................4-2
4.4.5 Auxiliary I/O.......................................................................................................................4-3
4.5 CONTROLLING CONNECTIONS................................................................................................4-3
4.5.1 Web Browser Control.........................................................................................................4-3
4.5.2 Serial or Telnet Connection Control..................................................................................4-4
5SECURITY......................................................................................................................................5-1
5.1.1 Password Setting................................................................................................................5-1
6NXU-2B FIELD OPTIMIZATION GUIDE ................................................................................6-1
6.1 RADIO INTERFACE USING JPS CUSTOM RADIO CABLES........................................................6-1
6.1.1 RX Audio Input Level.........................................................................................................6-2
6.1.2 TX Audio Output Level.......................................................................................................6-2
6.1.3 VOX/VMR Sensitivity.........................................................................................................6-2
6.1.4 TX Audio Delay..................................................................................................................6-2
6.1.5 RX Audio Delay..................................................................................................................6-3
6.2 RADIO INTERFACE USING CUSTOMER-DESIGNED RADIO CABLES........................................6-3
6.3 RADIO INTERFACE TROUBLESHOOTING TIPS .........................................................................6-4
6.3.1 Symptom: User in Field Complains of Missed First Syllables ..........................................6-4
6.3.2 Symptom: User in Field Complains of Missed Syllables Mid-Conversation.....................6-4
6.3.3 Symptom: User in Field Complains of Dropped Audio.....................................................6-4
6.3.4 Symptom: Continuous Ping-Pong between Cross Connected Radios ...............................6-4
6.3.5 Symptom: False Keying of Donor Radio by Radio Channel .............................................6-5
6.3.6 Symptom: Radio Channel Experiencing Continuous Active COR State............................6-5
6.3.7 Symptom: Audio Sounds Too Weak....................................................................................6-5
6.3.8 Symptom: Audio Sounds Too Loud or Distorted................................................................6-5
6.4 TROUBLESHOOTING TABLE....................................................................................................6-6
7NXU-2B FIRMWARE UPDATE..................................................................................................7-1
7.1 NXU-2B FIRMWARE UPDATE PROCEDURE............................................................................7-1
8NXU-2B FAQ (FREQUENTLY ASKED QUESTIONS)............................................................8-1
8.1 GENERAL ................................................................................................................................8-1
9INDEX .............................................................................................................................................9-1

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List of Figures
FIGURE 1-1 NXU-2B BASIC BLOCK DIAGRAM...................................................................................... 1-2
FIGURE 1-2 TWO NXU-2BS ENABLING A RADIO REPEATER FUNCTION............................................... 1-7
FIGURE 1-3 NXU-2B PAIR CREATES REMOTE DISPATCH CAPABILITY USING AN LE DEVICE............. 1-8
FIGURE 1-4 NXU-2BS CONNECT RADIO CHANNELS TO AN ACU-Z1 INTEROP SYSTEM ...................... 1-8
FIGURE 1-5 SINGLE NXU-2B CONNECTS A RADIO CHANNEL TO A JPS VIA PTTOCCHANNEL........... 1-9
FIGURE 2-1 FRONT AND REAR VIEWS.................................................................................................... 2-3
FIGURE 2-2 NXU-2B INTERNAL CONFIGURATION JUMPERS................................................................. 2-4
FIGURE 2-3 DTE VERSUS DCE SERIAL CABLES.................................................................................... 2-9
FIGURE 3-1 NXU-2B CONFIGURATION PAGE......................................................................................... 3-2
FIGURE 4-1 NXU-2B CONNECTION MANAGEMENT SCREEN................................................................. 4-3
FIGURE 5-1 WEB ACCESS WITH PASSWORD PROTECTION .................................................................... 5-1
FIGURE 5-2 NETWORK PASSWORD DIALOG.......................................................................................... 5-2
FIGURE 7-1 FIRMWARE UPLOAD............................................................................................................ 7-1
List of Tables
TABLE 1-1 SPECIFICATIONS............................................................................................................ 1-3
TABLE 1-2 EQUIPMENT AND ACCESSORIES SUPPLIED.................................................................... 1-4
TABLE 1-3 OPTIONAL EQUIPMENT -NOT SUPPLIED....................................................................... 1-4
TABLE 2-1 NXU-2B JUMPER SETTINGS [DEFAULT SETTINGS IN BOLD TEXT].............................. 2-4
TABLE 2-2 BASIC INSTALLATION CHECKLIST ................................................................................ 2-5
TABLE 2-3 NXU-2B PINOUT (AUDIO/CONTROL PORT) ................................................................. 2-6
TABLE 2-4 J4 SERIAL PORT PINOUT ............................................................................................... 2-8
TABLE 5-1 TROUBLESHOOTING TIPS .............................................................................................. 6-6

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vii Interoperability Now!
Glossary
Glossary
COR
Carrier Operated Relay
A signal from a receiver that gives a positive indication that a
carrier or signal is being received and that the receiver is
unsquelched. It has the same function as Carrier Operated
Squelch (COS).
COS
Carrier Operated Squelch
See COR.
DHCP
Dynamic Host
Configuration Protocol
A method of automatically assigning an IP address to an
Ethernet device at startup time. This method conserves IP
addresses in networks where devices do not stay connected
permanently.
DSP
Digital Signal Processor
A type of microprocessor, which is optimized for signal
processing functions.
IP
Internet Protocol
A protocol designed to allow communications between
computers on different networks.
LAN
Local Area Network
A group of computers and associated devices that share a
common communications line, typically within a small
geographic area.
PTT
Push-To-Talk
A control signal to a radio transmitter that controls the actual
transmission of radio frequency energy over the air. Also
called a keyline.
TCP
Transmission Control
Protocol
An additional layer to the Internet Protocol, which ensures
delivery of packets, sent across the network. It can handle
situations such as lost packets or packets arriving out of order.
UDP
User Datagram Protocol
An additional layer to the Internet Protocol which does not
ensure delivery of packets but which offers much lower
transmission overhead than TCP.
VoIP
Voice over Internet
Protocol
Also called Voice over Packet (VoP), a method of sending
voice communications across a digital network.
WAN
Wide Area Network
A network, which is spread out over a wider area, such as
around a city or state. It may include other public or shared
networks.

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Interoperability Now!
1General Information
1.1 Scope
This instruction manual provides the information necessary to install and operate the NXU-2B
Network Extension Unit.
1.2 Description
1.2.1 NXU General
NXU stands for Network Extension Unit. NXU units connect communications equipment to a
digital network using VoIP (Voice over Internet Protocol) technology. NXU units use JPS’
proprietary technology, embodied in a family of hardware and software products that enable
voice communications devices to be interconnected via a network across the room or around the
world. VoIP is a means of digitizing voice signals and transmitting them over a digital network,
such as a LAN, WAN, or even the Internet itself.
The NXU-2B is standards-compliant and therefore supports standards-compliant web browsers,
including Microsoft Edge, Firefox, Chrome, Opera, and Safari. It’s always best to use the most
current version of any web browser.
The NXU-2B is intended for use with radio communications consoles, communications radios,
and JPS products such as the ACU-1000 Interconnect Unit. This general-purpose, stand-alone
device interfaces full duplex audio, one RS-232 port, and three status bits onto an Ethernet
network. A pair of NXU-2Bs can form a simple system that creates a transparent communications
link between the two. The NXU-2B at one end (usually the equipment end) is the server; the one
at the other end (usually the operator end) is the client. The audio, RS-232, and status bits are
transparently transferred between the server and the client.
Any NXU-2B can be set up as a server or as a client depending on system needs. The RS-232
interface allows for different baud rates between the server and the client.
The NXU-2B monitors its network connection and adjusts its parameters automatically to
provide optimum performance under varying network conditions. Front panel indicators display
the unit’s status. Configuration is done through the NXU-2B’s Ethernet port using a standard
web browser.
Designed for years of continuous operation in mission-critical applications and remote locations,
the NXU-2B has no moving parts and requires no periodic shutdown or maintenance. Startup
upon power on is under 10 seconds.

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1.2.2 Advantages of NXU Technology
Enables the design of low cost, extremely flexible radio communications networks.
Multiplexes voice audio and data over a standard Ethernet network.
Uses existing network infrastructure eliminating the need for leased lines and
microwave sites.
Eliminates the requirement for pilot tones and other in-band signaling.
Facilitates centralized control of a communications network from a single computer.
1.3 Network Details
The NXU-2B is a 10/100BASE-T Ethernet device and each unit has a unique Ethernet address
and an RJ-45 physical interface jack. A 10/100BASE-T device operates at either 10 or 100 Mbps
and interconnects to an Ethernet hub or switch using standard CAT 5 twisted pair cable, also
known as UTP. The maximum cable length between an NXU-2B and its hub port is 100 meters.
With the right connective equipment (recommended or supplied by JPS), the NXU-2B’s Ethernet
port can be linked with virtually any LAN, WAN, or the Internet, no matter which topology or
cabling system is in use.
Figure 1-1 NXU-2B Basic Block Diagram
Audio In
Audio Out
RS-232
COR
PTT
AUX In
AUX Out
Ethernet
NXU-2

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1.4 Specifications
Table 1-1 Specifications
RX Audio Input
Input impedance
Balanced 47k ohms, transformer coupled, 600 ohm selectable
Input Level
Incoming signals adjustable from -26 to +10 dBm to set 0 dBm nominal input;
+15 dBm clipping. +20 dB boost configurable
Frequency Response
10 Hz to 3600 Hz +/- 2dB.
TX Audio Output
Output Impedance
Balanced 600 ohms, Transformer Coupled.
Output Level
Adjustable from –26 to +10 dBm, 0 dBm nominal factory default; +15 dBm
clipping into a 600-ohm load.
Frequency Response
10 Hz to 3350 Hz +/- 2dBm.
Distortion
0.5% or less (excepting Vocoder).
COR & AUX Input
Input impedance
47k ohm pull-up to +5V.
Polarity
COR: Selectable active low or active high; AUX Inputs: Active low.
Threshold
+2.5V nominal.
Protection
Up To + 100 VDC.
PTT and AUX Output
Output Type
Open drain, 47k ohm pull-up to +5V, PTT relay output selectable
Maximum Sink Current
100 mA for open drain, 300 mA for PTT relay
Max Open Circuit Voltage
+60 VDC for open drain, +100 VDC for PTT relay
Serial Interface
Interface Type
RS-232, Asynchronous, Full Duplex.
Baud Rates
300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 bps.
Connector
DB-9 Male, Standard PC/AT DCE Pinout.
Network Interface
Interface Type
10/100BASE-T Ethernet, 10 or 100 Mbps; RJ-45 Connector.
Protocols
Audio and status-UDP, RS-232- TCP.
Audio Vocoder
Selectable, 13, 16, 24, 32, or 64 Kbps data rate.
General/Environmental
Programming/Configuration
Web, Telnet, or RS-232 Interface.
Front Panel
Power, Link Active, Channel Active, and Audio Level LEDs.
Rear Panel
Audio/Data (DB15 Female), Serial, Network, and Power Connectors.
Input Power (12 VDC Nom)
+11 to +15 VDC @ 0.5A max. Wall cube supplied operates on 100-240 VAC.
Power Connector
Coaxial Jack, 2.5 mm ID, 5 to 5.5 mm OD; Center Pin Positive; Reverse
Polarity Protected.
Size and Weight
1.36”H x 6.50”W x 6.50”L (3.45 x 16.5 x 16.5 cm). 1.2 lbs. (0.5kg).
Temperature
Operating: -20 to +60 degrees C. Storage: -40 to +85 degrees C.
Humidity
Up to 95% @ 55 degrees C.

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1.5 Equipment and Accessories Supplied
Table 1-2 Equipment and Accessories Supplied
NXU-2B Shipping Level - JPS P/N 5190-200000
Quantity
Item
JPS P/N
1
NXU-2B Final Assembly
5190-201000
1
DC Power Supply [100 to 240 VAC, 47-63 Hz to +12 VDC, 500 mA]
1620-240061
1
Accessory Kit
5190-200150
1.6 Optional Equipment - Not Supplied
Table 1-3 Optional Equipment - Not Supplied
Description
JPS P/N
Operation & Maintenance Manual, printed and bound
Note: This manual may be downloaded from the jpsinterop.com website at no cost
5190-200200
Generic Radio Interface Cable; unterminated at radio end; 15 ft.
5961-291115
Interface cables for a very wide range of commercial radios are available for purchase.
Email JPS or consult the JPS Interoperability Solutions website for a listing:
Email: [email protected] / s[email protected]
www.jpsinterop.com

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1-5 Interoperability Now!
1.7 Differences Between the NXU-2B and the NXU-2A
The NXU-2B is an updated and improved redesign of the popular NXU-2A device. Tens of
thousands of the NXU-2As are currently in operation, and the NXU-2B maintains compatibility
with those units.
Some improvements extend beyond the incorporation of updated electronic components and are
listed below:
•The pinout of the Audio/Control connector on the rear panel of the unit is different
between the NXU-2A and the NXU-2B. The NXU-2B pinout has been changed to match
that of other JPS products such as the ACU product family. This allows standard JPS
radio cables to be used with the NXU-2B with no adapter needed. Previously an audio
crossover adapter was included with the NXU-2A to allow standard JPS radio cables to
be used. This adapter is not required with the NXU-2B and is not included. Please refer
to Table 2-3 for the pinout of the Audio/Control connector.
•The NXU-2B uses transformer-coupled balanced audio for both input and output audio.
The NXU-2A only had balanced input audio and single-ended output audio.
•The NXU-2B audio input and output levels are electronically adjustable via the web
browser interface and are saved in non-volatile memory. This allows audio level
adjustments without requiring the operator to be at the location where the NXU-2B is
installed. The NXU-2A had rear panel mechanical potentiometers for the adjustment of
audio input and output levels. This upgrade prevents any need to travel to a remote radio
site if audio level optimization is desired.
•The NXU-2B uses hardware relay contacts for PTT output while the NXU-2A had a solid-
state (open drain transistor) keying output. There is a jumper selectable solid-state output
available on the NXU-2B as well, but the default is to use the relay for PTT. The relay
allows for higher keying voltages and currents than the solid-state output.
Note: If replacing an existing NXU-2A with an NXU-2B, be sure to remove the
adapter at the rear panel AUDIO/CONTROL connector (assuming one is being used).
This adapter is not needed when using a JPS Radio Interface Cable with an NXU-2B.

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1.8 NXU-2B Overview
JPS Interoperability Solutions has four decades of experience with voice communications
interoperability, fielding their first devices in 1989. Over this time the company has encountered
and resolved a wide array of problems that can hamper or complicate communications when
disparate devices are patched together into interoperability nets.
The NXU-2B incorporates all this experience, in the form of:
oA suite of sophisticated DSP algorithms that operate at the unit’s analog and network
interfaces. allowing optimized performance with connected communications devices.
oCustom radio interface cables, designed by the JPS Systems Engineering Department,
for use with well over 300 different radio makes and models.
JPS interoperability devices are also known for simplicity and ease-of-use. The NXU-2B’s
browser-based Graphical User Interface is designed to make these sophisticated capabilities
easily accessible when necessary, but unobtrusive when not needed.
1.8.1 Important definitions:
COR: (Carrier Operated Relay) A signal that indicates when a radio (or other
type of communications device, such as an NXU-2B) is receiving a valid audio
signal.
PTT: (Push-to-Talk) A control signal that tells a radio (or other communications
device) to transmit the audio signal being sent to it.
Full Duplex Communication System: Users can simultaneously talk to and
listen (for example, a standard telephone call).
Simplex or Half Duplex Communication System: Only one system user can
be heard at a time.
Interoperability Net: Communications link consisting of disparate devices (such
as radios of different types or frequencies, telephones, VoIP phones, etc.)
connected together, similar to a conference call.
These definitions are essential in understanding the basic operation of an interoperability device,
such as a JPS ACU Gateway or this NXU-2B. That is: If multiple communications devices are
engaged in an interoperability net, whenever one device detects active COR (valid audio input),
that audio, along with a PTT signal, is sent to all other devices in the net to be retransmitted.
Also, if any device in an interoperability net is half duplex (such as are almost all radio systems),
then all communications must be half-duplex. The NXU-2B supports full and half-duplex modes.
Among the unit’s sophisticated features are various methods for determining active COR such
as VOX (Voice Operated Switching) or VMR (Voice Modulation Recognition) which are
optimal or necessary for some types of devices, and adjustable audio delays to meet the timing
requirements of the connected communications systems and prevent lost syllables at the start or
end of a transmission.

NXU-2B Operations Manual
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1.8.2 Configuration
The unit is configured via its web-based GUI. There are no physical potentiometers or switches
related to the analog interface configuration. See the NXU-2B manual for instructions on
configuration and adjustment.
1.8.3 Basic Applications and Operation
In many applications, the NXU-2Bs operate in pairs –one unit is configured as a server while
the other unit is configured as a client. The client unit is programmed to connect to the IP address
of the server unit. When the network connection between the units is established, a transparent
connection is created between the audio inputs and outputs of each device, as well as the
complements of each control signal. When the COR signal is active on one device, audio received
on that device is transported over the network and reproduced at the audio output of the second
device, and its PTT output is activated. Additionally, any RS-232 data received on one device is
also sent over the network and is transmitted from the RS-232 port of the second device. This is
the essence of the “Network Extension Unit” name – the devices act similarly to a long cable, if
you think of the associated IP network as that cable.
The NXU-2B is useful for remote radio linking (see Figure 3 below), allowing a LAN, WAN, or
the Internet to be used in place of expensive leased lines.
The NXU-2B is also compatible with the extensive JPS ACU family of radio interoperability
gateways; all have the capability for RoIP channels/interfaces.
Figure 1-2 Two NXU-2Bs Enabling a Radio Repeater Function
A simple application of the NXU-2B. A pair of the devices are used to connect a pair of radio
channels. Note that an Active COR (unsquelched) condition on one of the radios causes its RX
audio to be sent via its associated NXU-2B across the network to the other NXU-2B/radio pair.
The NXU-2B on the other side of the network transforms the RX audio into TX audio, and the
Active COR into Active PTT.
An RS-232 serial data stream can also be sent across the network.

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Figure 1-3 NXU-2B Pair Creates Remote Dispatch Capability Using an LE Device
A pair of NXU-2Bs connect an LE audio console device to a radio over the IP network. The basic
function is similar to the radio-to-radio system, except that one radio is replaced by the LE device.
Figure 1-4 NXU-2Bs Connect Radio Channels to an ACU-Z1 Interop System
The new JPS “Z” product line of interoperability gateways also includes RoIP interfaces, and
therefore the NXU-2B can be used to interface radios and other 2/4 wire devices to them. The
ACU-Z1 modular gateway shown in the upper left can make up to 12 local connections using its
plug-in modules. It also has the capacity to include a large number of virtual streaming channels,
enabled by the NXU-2Bs at the right or the two-channel RSP-Z2 depicted in bottom center.
Similarly, the new Z2 Controller (not shown) can handle a large number of virtual streaming
channels. Contact JPS for more information or visit our website: www.jpsinterop.com

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1-9 Interoperability Now!
Figure 1-5 Single NXU-2B Connects a Radio Channel to a JPS VIA PTToC Channel
Just as its predecessor, the NXU-2A did, the NXU-2B can be used to connect a radio channel to
a variety of Push-To-Talk over Cellular (PTToC) applications, including the JPS VIA app.

NXU-2B Operations Manual
1-10
End of Section One

Interoperability Now!
2-1
2Installation
2.1 General
This section provides the instructions for unpacking, inspection, installation and set-up. Also
included are directions for reshipment of damaged parts or equipment.
2.2 Unpacking and Inspection
After unpacking the unit, retain the carton and packing materials until the contents have been
inspected and checked against the packing list. If there is a shortage or any evidence of damage,
do not attempt to use the equipment. Contact the carrier and file a shipment damage claim. A
full report of the damage should also be reported to the JPS Customer Service Department. The
following information should be included in the report:
Order Number
Equipment Model and Serial Numbers
Shipping Agency
Date(s) of Shipment
TheJPS Customer Service Department can be reached by phone at [phone]. Upon receipt
of this information, JPS will arrange for repair or replacement of the equipment.
2.3 Reshipment of Equipment
If it is necessary to return the equipment to the manufacturer, a Returned Material Authorization
(RMA) number must first be obtained from JPS, following the procedure outlined on the JPS
website. This number must be noted on the outside of the packing carton and on all
accompanying documents. When packing the unit for reshipment, it is best to use the original
packaging for the unit; if this is not possible, make sure that adequate packing material is used to
prevent excessive shocks during transport and handling.
Shipment should be made prepaid consigned to:
JPS Interoperability Solutions
Customer Service Department
5800 Departure Drive
Raleigh, North Carolina 27616
USA

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Plainly, mark with indelible ink all mailing documents as follows:
GOODS RETURNED FOR REPAIR
Mark all sides of the package:
FRAGILE - ELECTRONIC EQUIPMENT
Inspect the package prior to shipment to be sure it is properly marked and securely wrapped.
2.4 Installation Overview
NOTE: NXU-2B installation requires knowledge of Ethernet network fundamentals
as well as a basic understanding of Internet Protocol (IP). As with any network-
connected device, improperly configuring and installing the NXU-2B could disrupt
proper network operation. Please seek the assistance of your network administrator
or other knowledgeable person if you are unsure about how your network is
configured.
The following six steps are needed to properly install the NXU-2B:
1. Determine the IP address, subnet mask, and (if applicable) the gateway address for the
unit. You may have to contact the network administrator for your organization to obtain
this information.
2. Provide the proper primary power for the unit.
3. Interconnect the unit with the communications system via the NXU-2B's rear panel
connectors. The rear panel Audio/Control jack provides the lines necessary to interface
the NXU-2B to your audio equipment.
4. Configure the unit’s operational parameters per Sections 3.2 through 3.5.
5. Connect the unit to your Ethernet network.
6. Optimize the input and output audio levels per Section 4.4.2.
The NXU-2B is then ready to use.