Installation manual

NMEA 2000 PC Interface - NGT-1-USB
Page 5© 2009 Active Research Limited
Technical features
High-speed 32-bit ARM processor capable of up to 40
million instructions per second.
Flash ROM technology that supports automatic
programming for quick and easy updates, 10,000+ erase
cycles and a 10-year Data Retention provides carefree
user conguration.
On-chip memory store allows buffering of short term
NMEA data, allowing the unit to smooth short-term peaks
in the NMEA data ow.
Fully congurable via the USB or over the NMEA 2000
network allowing optimization of the PC interface to better
suit the system it is a part of.
NMEA 2000 interface, opto-isolated to 2500 volts,
protecting the system even during the most extreme
fault conditions and fully compliant with the NMEA 2000
standard for interfacing with the NMEA 2000 network.
Separate USB and NMEA 2000 network power offer
easy installation with no need for a direct connection to
the vessels main battery supply. The NGT-1-USB takes
power from the USB connection to power its USB circuitry,
and power from the NMEA 2000 connection to power its
NMEA 2000 circuitry. This creates total isolation between
both power sources to completely eliminate the risk of
ground loop faults occurring.
Software updates
The NGT-1-USB’s built-in rmware is held in “ash”
memory, allowing quick and easy upgrades using either
the latest NGT-1-USB ActiPatch, or alternatively the
NMEA 2000 Gateway Conguration Tool running on a
PC connected to the NGT-1-USB.
It is our policy to provide these updates free on the
Actisense website (www.actisense.com), so that the
NMEA 2000 PC Interface (NGT-1-USB) can become
more sophisticated with time, and should there be any
bugs reported in the rmware, they can be promptly xed
without the unit requiring to come out of commission.
Connecting devices together
The NMEA 2000 standard
The NMEA 2000 system is a low-cost data network
operating at 250 kbits/sec utilizing the Controller Area
Network (CAN). Multiple devices can be connected
together on a single trunk cable to simply and easily share
information between themselves.
NMEA 2000 uses a shielded cable and a ”differential”
signalling scheme, whereby two wires are used to transmit
the NMEA data named CAN High and CAN Low. These
connections will be labelled as “NET HI” and “NET LO”
respectively. Power is also supplied through the NMEA
2000 cable named NET Supply and NET Common. These
connections will be labelled “NET SUP” and “NET COM”
respectively on the PCB.
Please refer to the Connecting to the NMEA 2000
Network section for an example of these connection
methods.