The Brookhouse eMux
Integration of NMEA 0183 server and on-board wifi network
After the introduction of the Brookhouse iMux in 2010, the new
Brookhouse eMux now takes NMEA 0183 over wifi a step further with integration of NMEA 0183 and on-board wifi
Navigation with iPads and other i-devices
has come of age. Oceans have been crossed with the iPad as the main
navigation tool, receiving instrument data from the iMux via wifi. Today
we find that many vessels, not only super-yachts or commercial vessels,
have on-board wireless networks with (3G) routers for internet
access in coastal areas while under way, on anchorages and in harbour.
The Brookhouse eMux makes good
use of the local network and wifi capabilities of the router, also
when the vessel is out of range of cellular service. Installation
of a router on board is worthwhile even if cellular service is never
used. A reliable, feature-rich, on-board wireless network can be
created at low cost, which is ideally suited for integration of
multiple iPad use with the boat's instrument network.
eMux interfaces directly to the router via a reliable RJ45 ethernet
cable connection. NMEA 0183 GPS, AIS and other instrument data is
combined by the multiplexer/server in one data-stream and is available
to network users. iPads, iPhones and laptops can receive the
data simultaneously via wifi. One of the clients can also control the
auto pilot for track-mode steering to a waypoint or along a route and
waypoints can be transferred to other network clients or a chart
plotter. The eMux also has a serial port for connection of a chart
plotter or computer.
Benefits and features
iPads, iPhones, Androids and computer,
can access the boat's NMEA instrument network
via the same on-board Access Point (SSID) with same settings as for
Internet access via 3G.
Reliable RJ45 ethernet
connection of the eMux to the router.
All the rich features offered by the router,
including security/encryption can be used to access navigation data.
In most cases the eMux can be
installed without complicated configuration.
The router can be easily
configured from an iPad or computer, by accessing its internal configuration web
Advantages of using a router's
3G internet access as opposed to individual cellular access by each iPad/iPhone.
Superior signal quality for
all users as result of high gain aerial and booster (if
installed). On anchorages or in remote harbours with poor 3G signal
quality, direct access by iPad-3G or other devices to cellular data
services may be very slow, intermittent or impossible.
One SIM card in router only,
iPads/iPhones, computers and Androids share access. When visiting foreign harbours
(prepaid) SIM card can be purchased, only for the router. This will
provide local cellular internet access for all on-board users.
Wifi-only iPads, i.e. iPads or
other tablets without 3G capability,
can be used for 3G cellular internet access via router.
If the router is a model
with analog telephone connector, voice calls can be made via the
router, with the benefit of the superior signal quality provided by
the marine aerial and booster (if installed).
The standard eMux NMEA server combines GPS and NMEA
0183 instrument data from three 4800 baud ports with AIS receiver or
transponder data from a 38400 baud input port. The combined data stream
is transmitted via TCP/IP over an RJ45 ethernet cable to a
router. The eMux also has a serial output port for a hard-wired connection to a
chart plotter and/or a computer. NMEA data received back via TCP/IP is
output from the eMux NMEA OUT port at 4800 baud for auto pilot control
in track mode or for waypoints transfer. All of the functions of the Brookhouse
multiplexer model AIS including filtering and NMEA sentence editing on
the fly are available in the eMux.
The eMux-ST model (as in the diagram
above) offers the same features
as the standard model, and in addition Raymarine Seatalk protocol is
converted to NMEA 0183. If the Seatalk port is enabled (by default for
model ST) 3 of the 4 NMEA input ports can be used. The Seatalk
port can also be disabled in the setup-menu. In this case all 4 NMEA
ports are available, and the unit's functionality is identical to the
The eMux is easy to install, no configuration is necessary unless the advanced features need to be enabled.
iMux or eMux?
The main differences between the two is the wifi communication
and the supported number of simultaneous users.
The iMux has its own internal wifi module while
the eMux delegates the wifi task to a router, and is connected
to the router via a cable. As a consequence, the eMux can stay
connected to the same AP (the router) for both navigation and access to
the internet via 3G.
The multiplexer part of the iMux and eMux is
Specifications standard eMux
4 opto-isolated “NMEA Listener” (Input) ports, 3 at 4800 bps, 1 at 38400 bps for
1 RS232 output port for connection to a chart plotter or
1 RS232 input port
(baudrate conversion input).
1 Output RS422 port (differential NMEA talker port) 4800bps
(baudrate conversion output)
1 RJ45 port for connection to a router or
computer ethernet LAN port.
Baudrate conversion 38400bps-4800bps.
Indicators: red LED for power, green LED for data-transmission.
Supply Voltage: DC 9-35 Volts.
Reversed polarity protection.
Physical size: 110x65x37mm (hxwxd)
Weight: 140 grams
Mounting: bulkhead mounting with screws.
NMEA management and control:
Specifications are the same as for the standard model with 2 exceptions:
Instead of 3 NMEA 4800 input ports the eMux-ST has 1 Seatalk port and
2 NMEA 4800 baud input ports. If the Seatalk port is disabled, a 3rd NMEA input
@ 4800 is available.
Seatalk GPS data, if available, is always sent to the 4800
NMEA output port as input for a DSC radio.
*All popular AIS receivers and transponders are supported.
Pricing, ordering and payment
Note: Seatalk is a trade-mark of RayMarine.
Back to top of page