The NX-100S network audio adapter provides transmission of audio and control information over IP networks. This may be over a LAN, or can be extended using dedicated lines or the internet, for transmission to remote areas. A unit is installed at each of the locations which are to receive and/or transmit audio, and connected together by the IP network. Each unit will then connect to up to 64 other units, to give two-way audio streaming and general purpose control using contact closures. Applications include multipoint broadcasting of paging and background programme, to remote areas such as railway platforms and supermarket chains, as well as the monitoring of equipment and audio at remote sites, offering the greater reliability of a hardware-based solution rather than a software application.
The rear panel has a coaxial DC power input for an optional AD-246 AC adapter (must be purchased separately). The network connection is RJ45 which may be connected to a hub, or to a PC or router by using a cross-over lead. This connection is used to set up the unit. Two mini-Phoenix style connectors provide eight general-purpose control inputs and eight outputs respectively. Audio input and output are balanced via mini-Phoenix style connectors. The input has associated mic/line switch and volume control, with phantom power available for condenser microphones. The front panel has Link/Activity, Full-Duplex/Collision, Status, Error, Run, Signal and Peak LED indicators, as well as a recessed reset button which may be accessed using a suitable sharp point. The unique MAC address of the unit is printed helpfully on the panel.
Software on CD is supplied, to be installed on a PC in order to set up the unit. The software supports Windows 2000/XP, and is used to connect to the unit/units via the IP network connection. Java runtime environment is required, supplied on the CD. The software, once installed will scan a local network and locate all the NX-100S units on it. Note this will not work through routers. The software has tools to assign networking details to the units it discovers. Once the desired transmission parameters have been set, further tools may be used to set up virtual zones to which broadcasts may be sent, which may be controlled from a PC, or may be configured for actuation by the general purpose control inputs. NX-100S units on different network segments (eg the internet) may be manually added to the system and maintained remotely using the NX-100S embedded web server.
Audio packets are sent either in Unicast or Multicast modes. In the former case, four different simultaneous transmissions may be sent to up to four other NX-100S devices. In Multicast mode, the same transmission may be sent to up to 64 locations. Various parameters may be adjusted to provide for different capacity connections. ‘Voice packet loss recovery’is a function to compensate for the loss of voice packets due to communications interference. There are three modes: Silence; sections without voice packets are processed as silence): Redundancy; enables the audio to be output normally, for continuous losses of up to eight packets: Retransmission; enables the audio to be output normally for continuous losses of up to 15 seconds. Packet size may be set between 8 and 1024 bytes; sampling frequency between 8kHz and 32kHz. These settings will determine the bandwidth used on the network, and the time delay imposed.
The depth of control and operational options for these units is far too deep for even a resume here. If further specific detail is required, please down load a copy of the manual (see the linked resources).
Bandwidth used by a single, one-way, audio stream:
Note (1): The suggested bandwidth allows for bi-directional audio streams; additional bandwidth will be required for transmission of any control signals.
Technical Specification:
| Audio input: |
Balanced, transformer isolated, -58dV to 0dBV, 2kohms |
| Audio output: |
Balanced, transformer isolated, 600ohms minimum load impedance |
| Frequency response: |
50-14,000Hz, at a sampling frequency of 32kHz |
| Distortion: |
0.3% at 1 kHz, sampling frequency 32kHz |
| Control inputs: |
Eight plus common ground, open voltage 12V DC, short-circuit current 10mA |
| Control output: |
Eight plus common ground, open collector output, withstand voltage 30V DC, current 50mA maximum |
| Network I/F: |
10BASE-T/100BASE-TX, auto-negotiation |
| Network protocol: |
TCP/IP, UDP, HTTP, RTP, IPv6 compatible |
| Environment: |
0 to +50 degrees C, under 90% relative humidity, no dew condensation |
| Power source: |
AC: Optional AD-246 power supply, 220-230V AC, 50/60Hz |
| Dimensions: |
210(w) x 46(h) x 188(d)mm |
| Weight: |
1.2kg |
Included accessories: CD (PC setting/operation software program), mating connectors for DC input, audio I/O, control I/O.
Optional accessories :Rack mounting brackets: MB-15B-BK, MB-15B-J, for one and two units respectively. AD-246 power supply; has IEC inlet, supplied with AC cordset. Captive lead to NX-100S.
Usage note
The sheer power and flexibility of these devices, which makes them adaptable to almost all ethernet network configurations, also result that a badly configured unit, or worse, units, could cause havoc on a LAN or WAN already in use for normal IT activities. It is advisable to consult with an appropriately expert network engineer before using an NX-100S unit outside it’s own dedicated LAN.