Actisense NGT-1-ISO User manual

NMEA 2000 PC Interface
(using the Actisense Comms API)
NGT-1-ISO
(All hardware revisions)
Installation Manual
Issue 1.01
 Gateway to connect between a PC’s serial (RS232) port and the NMEA
2000 network
 Uses the Actisense Comms API for bi-directional PC communications
 Complete electrical isolation (of 1500 volts) between serial port and the
NMEA 2000 connections
 Fully congurable via serial port or through the NMEA 2000 network

Page 3© 2013 Active Research Limited
Contents
Important notices 4
Notices 4
Foreword 4
Introduction 4
Technical features 5
Software updates 5
Connecting devices together 5
The NMEA 2000 standard 5
Connections 6
Connecting to the NMEA 2000 network 7
NMEA 2000 connections 7
Connecting to an RS232 (PC) port 7
RS232 Connections 7
Specications 8
Troubleshooting guide 9
Status LEDs 9
Product order codes 10
Company Information 10

Page 4© 2013 Active Research Limited
Important notices
Actisense and the Actisense logo are registered
trademarks of Active Research Limited. All rights are
reserved. The contents of this manual may not be
transferred or copied without the expressed written
permission of Active Research Limited. All other
trademarks are the property of their respective owners.
The Actisense NMEA 2000 PC Interface (NGT-1-ISO)
is intended for use in a marine environment, primarily for
below deck use. If the NGT-1-ISO is to be used in a more
severe environment, such use may be considered misuse
under the seller’s guarantee.
The NGT-1-ISO has been certied to comply with the
European directive for Electro-Magnetic Compatibility
(EN60945), and is appropriately CE marked. Operation
of the unit should be in conjunction with appropriate
CE approved shielded connectors and cabling used in
accordance with the CE directive EN60945. Any EMC
related issues should be reported to Active Research
immediately to allow the company to rectify or resolve
EMC related problems in accordance with its obligations
under EN60945.
If the unit is misconnected so that compliance failure
occurs, the company shall not be held responsible for
compliance failure until suitable EMC guidelines for
connection are seen to have been taken.
Notices
When using this document, please note the following:
The products described in this manual and the
specications thereof may be changed without prior notice.
To obtain up-to-date information and/or specications,
contact Active Research Limited or visit the Actisense
website (www.actisense.com).
Active Research Limited will not be liable for infringement
of copyright, industrial property right, or other rights of a
third party caused by the use of information or drawings
described in this manual.
Active Research Limited will not be held responsible for
any damage to the user that may result from an accident
during operation of this unit when used in accordance with
this document.
Foreword
At Active Research Limited, we recognise that instructions
are often skipped, so we have aimed to write this
document in an informative and direct manner that will aid
the user. We have covered all the points a typical user
needs to know.
Please read all sections before installing and using the
NGT-1-ISO, and any related software programs.
Introduction
The NGT-1-ISO allows installers of equipment to adopt
the NMEA 2000 network early, and enjoy the advantages
of a single bus connection to all marine electronic devices
around the entire boat.
The NMEA 2000 network reduces installation costs of
marine equipment and greatly reduce a boat’s wiring
harness complexity, leading to improved reliability and
reduction in unnecessary weight. Now only a single cable
is required from the bridge to the engines, sensors and all
other NMEA 2000 instruments on the boat
NMEA 2000 uses the “CAN Bus” system (prevalent in
most modern cars), to provide the quality and security of
data transmissions that the NMEA 0183 bus can never
hope to provide. This enables NMEA 2000 products to
achieve better data transmission reliability in the passage
of data through the vessel.
The Actisense ‘Certied Software’ programme offers
PC software manufacturers a quick method of adding
an NGT-1 interface to their products - allowing them to
share and interact safely on the NMEA 2000 network via
the PC’s serial port. The NGT-1 interface acts much like a
rewall - preventing illegal operations and maintaining the
integrity of the NMEA 2000 network.
As more PC software manufacturers use the NGT-1
interface to offer NMEA 2000 support to their customers,
more users will experience the benets of NMEA 2000.
Full information on the complete Actisense product
range and a list of all Actisense ‘NGT Certied Software’
products can be found on the Actisense website (www.
actisense.com).

Page 5© 2013 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 serial 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.
NMEA 2000 network powered to offer easy installation
with no need for a direct connection to the vessels main
battery supply. The NGT-1-ISO takes all its power from
the NMEA 2000 network connection and contain a clever
built-in power isolator to supply its serial port circuitry
without the need of an extra battery source. This creates
total isolation between the serial and NMEA 2000 circuitry
to completely eliminate the risk of ground loop faults
occurring and the resulting damage.
Software updates
The NGT-1-ISO’s built-in rmware is held in “ash”
memory, allowing quick and easy upgrades using either
the latest NGT-1-ISO ActiPatch, or alternatively the
NMEA 2000 Gateway Conguration Tool running on a
PC connected to the NGT-1-ISO.
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-ISO) 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.

Page 6© 2013 Active Research Limited
Figure 1 shows an internal view of the NGT-1-ISO Printed
Circuit Board (PCB).
1. NMEA 2000 Interface
A ve way screw terminal block is supplied for
connecting the NMEA 2000 cable. The CAN interface
is fully compatible with the NMEA 2000 standard.
Actisense supplies a pre-tted four-core screened
cable for the NMEA 2000 connection, tted with a
male micro-t connector. The colour codes used for
this cable are:
Wire colour NMEA 2000
Shield / Screen SHIELD
Blue NET LO
White NET HI
Black NET COM
Red NET SUP
If you need to use your own NMEA 2000 cable, the
ve way screw terminal block is provided within the
NGT-1 to allow easy connection, along with a spare
cable gland that should be tted on to the new cable
to help maintain the water protection level.
Any such cable is required to conform in full to
the NMEA 2000 specication and be no longer
than 6 metres (maximum drop length).
2. NMEA 2000 indicator LED
This LED ashes when NMEA 2000 data to be
transferred is received by the NGT-1-ISO. It can be
clearly seen through the NGT-1-ISO’s translucent lid
when the case is closed.
3. Serial opto-isolated input.
Two screw terminals are provided to connect the
serial input. The serial input is of the differential opto-
isolated type and uses the unique Actisense low
current drain circuitry (2 mA @ 2.0 v).
4. Serial ISO-Drive output.
Three screw terminals are provided to connect to the
serial ISO-Drive output. The serial output comprises
of three connections: ‘+’, ‘-‘ and ‘Ground (GND)’.
The colour codes used for this cable are:
Wire colour Serial
Shield / Screen ISO Ground
Blue ISO Out B / -
White ISO Out A / +
Black Opto In B / -
Red Opto In A / +
In most installations, this ground (GND) can be
left disconnected. It is useful where an “RS485” or
“IEC61162-2” 3 terminal type connection is required,
or where ground continuity is needed between
source and target connections. No damage will be
caused by connecting to this GND in error. Always
follow the connection diagrams shown in this manual
to ensure correct operation.
5. Serial data indicator LED
This LED ashes when serial data to be transferred
is received by the NGT-1-ISO. It can be clearly seen
through the NGT-1-ISO’s translucent lid when the
case is closed.
To open the NGT-1-ISO, remove the two screws in the
base of the unit, then slide off the top of the case. The
cable glands need to be slid out from the top of the case
in order to access the internal connections. The NGT-1-
ISO circuitry will be left attached to the base of the unit
and the two supplied cables attached to their connectors.
Note: When opening the NGT-1-ISO case, be aware
that the circuitry inside is not 100% protected against
static electricity. Please ensure that, when opening
the case, you use precautions against static damage
by only touching the connector block and by holding
the unit by its plastic base. In this way, the risks of
static damage will be minimised.
Connections
Figure 1 – All external connections
3
1
25
4

Page 7© 2013 Active Research Limited
NMEA 2000 connections
The Actisense NGT-1-ISO is designed to be connected
to the vessel’s NMEA 2000 network using the supplied,
pre-tted Actisense cable.
If a different length cable is required, an NMEA 2000
certied cable of the required length (maximum 6 metres)
should be connected to the vessel’s NMEA 2000 network
using a standard NMEA 2000 connector.
The standard wiring connection can be seen in Figure 2.
Note:
1. Wire colours are for guidance only. The colours given
relate to the supplied Actisense cable and the NMEA
2000 standard cable denition.
Connecting to the NMEA 2000 network
Figure 2 – NMEA 2000 connections
CAN Network
NET COM
Shield
CAN Hi
CAN Lo
NET SUP
Connecting to an RS232 (PC) port
Figure 3 – RS232 port connections
RS232 Connections
The NGT-1-ISO can be connected to a PC communications
(RS232) port using the supplied Actisense cable and a
connector with the following specication:
1. A minimum of 3-cores are required in a shielded
cable. Higher quality cable will naturally yield higher
performance / higher Signal-to-Noise Ratio (SNR).
Most typical cables have two twisted pairs inside. In
this case, use one pair for the TX line and one for the
RX line. Use the spare wire in each pair as ground,
and connect the cable shield to ground only at the
computer end.
2. A D-type female (socket) connector for the PC end of
the cable.
3. The OUT +/A of the NGT-1-ISO should be connected
to the RX of the computer (standard D-type, pin 2)
and the NGT-1-ISO IN +/A should be connected to
the TX of the computer (pin 3).
4. Connect the IN -/B and OUT -/B together and
connect to the PC’s serial port ground (pin 5).
Personal
Computer
( 9 PIN 'D'
RS232
Port)
Do not
connect
RX
Pin 2
GND
Pin 5
TX
Pin 3

Page 8© 2013 Active Research Limited
Table 2 – NGT-1-ISO specications
All specications are taken with reference to an ambient temperature (TA) of +25°C.
Note:
1. Current consumption measured under no-load conditions
Specications
Parameter Conditions Min. Max. Unit
Supply
Supply voltage 8 35 V
Supply current (see note 1) Supply voltage = 12v 26 30 mA
Supply voltage = 24v 16 18 mA
NMEA 2000 CAN Bus line (CAN-H; CAN-L) Transmitter
Recessive bus voltage VTXD = VDD; no load. 2.0 3.0 V
Dominant bus voltage CAN-H VTXD = 0.8V 2.75 4.5 V
Dominant bus voltage CAN-L VTXD = 0.8V 0.5 2.25 V
Recessive differential output voltage VTXD = 2V; no load -500 50 mV
Dominant differential output voltage 40Ω < RL < 60Ω 1.5 3.0 V
Short circuit output current CAN-H VCAN-H = -5V - -200 mA
Short circuit output current CAN-L VCAN-H = -40V, +40V. (see note 2) - 200 mA
NMEA 2000 CAN Bus line (CAN-H; CAN-L) Receiver
CAN-H, CAN-L common-mode input
resistance 5 50 KΩ
Differential input resistance 20 100 KΩ
Opto-isolated Input
Input voltage tolerance Continuous operation -15 +15 V
Short term operation (< 1 sec) -35 +35 V
Differential input voltage Required level for data to be detected 1.8 - V
Input current - 2 mA
Input to Ground
Baud rate Congurable Baud rate 4800 230400 bps
ISO-Drive Output
Output current RS485 / RS422 / RS232 compatible - 20 mA
Differential output voltage 100 ohm load 2.1 - V
Output to Ground Full Galvanic isolation protection - 1500 V
Baud rate Congurable Baud rate 4800 230400 bps
General
Ambient operating temperature -20 +70 °C

Page 9© 2013 Active Research Limited
Troubleshooting guide
This guide will concentrate on all relevant troubleshooting issues above simple cable connection faults. Therefore,
the cables between the NGT-1-ISO hardware and any other devices should be checked as a matter of course, before
continuing with this guide.
Status LEDs
The NGT-1-ISO hardware has two bright LEDs that can be seen through the case to indicate when data is received
from either the serial device or NMEA 2000 network connection. It is an important point to note that these two LEDs can
only show when their respective data is RECEIVED; it is not possible to show both transmit and receive simultaneously
on a single colour LED.
These LEDs can be used to debug potential problems. If both an NMEA 2000 ‘talker’ and a ‘listener’ are connected, it is
possible to analyse which is working by disconnecting one of them or by stopping the PC software from sending data.
Sequence Description
NMEA 2000 LED does not
ash when the data is received
from the NMEA 2000 network
Check that the NGT-1-ISO is connected to the NMEA 2000 network, that the NMEA
2000 network is operational, and that the required PGN messages are selected for
transfer by using the NGT Conguration Tool.
Serial LED does not ash
when Serial data is being
received
Check that the NGT-1-ISO is connected correctly to a PC serial port, that COM port
is working in the Windows Device Manager, is selected by the software program
and that the required messages are selected to be transferred by using the NGT
Conguration Tool.
Both LEDs ash together,
once every 10 seconds
Indicates that the NGT-1-ISO is powered but no data is received from either
connection. If data should be being transferred through then check that the required
PGN messages are selected by using the NGT Conguration Tool.
If the error persists, please contact Actisense support to help trace the issue
before considering the return of the product. If Actisense support concludes
that the NGT-1-ISO unit should be returned to Actisense (refer to the Company
Information section), a Returns Number will be issued by the support engineer.
The Returns Number must be clearly visible on both the external packaging
and any documentation returned with the product. Any returns sent without a
Returns Number will incur a delay in being processed.
Table 3 – Diagnostic LED

Page 10© 2013 Active Research Limited
Active Research Limited
Unit 5 Wessex Trade Centre
Ringwood Road
Poole
Dorset. UK
BH12 3PF
Telephone: [phone] (International : [phone])
Fax: [phone] (International : [phone])
Actisense on the Web: For advice, support and product details
E-mail: [email protected]
Website: www.actisense.com
“Actisense” is a registered trademark of Active Research Limited.
Company Information
Product order codes
NGT-1-ISO NMEA 2000 ↔ Serial Interface with ISO-Drive
Special version required to connect the NMEA 2000 network to a serial port
(on a computer running Actisense certied software)
NGT-1-USB NMEA 2000 ↔ USB Interface
Standard version required to connect the NMEA 2000 network to a USB port
(on a computer running Actisense certied software)

NMEA 2000 Connection
•NMEA 2000 network is
opto-isolated from the serial
connection to offer 1500 volts
of protection
•NMEA 2000 current draw
30 mA typical
•Terminal block available for
user cable connection
•Cable length 1.5 metres
Opto & ISO-Drive Connection
•Exceeds all IEC 61162-2
electrical in/out specifications
•Compatible with RS422
(NMEA), RS232 & RS485
•Baud rates 4800 to 230400
•Cable length 1.5 metres
System Requirements
•Supported OS’s: Windows
(2000, XP and Vista). Check
website for other versions
•No drivers required
Environmental
•Recommended operating
temperature: -20°C to +70°C
•Splash proof plastic casing
provided with sealing cable
glands certified to IP54
•Stainless steel case screws
•Humidity: 0-80% RH
Guarantee
•3 years return to base
Certifications
•CE (EN60945)
•Tested and certified NMEA
2000 compliant
Specifications
Active Research Limited, Unit 5 Wessex Trade Centre, Ringwood Road, Poole, Dorset, UK, BH12 3PF
Telephone: [phone] Fax: [phone]
Actisense on the Web: For advice, support and product details
E-mail: [email protected] Website: www.actisense.com
“Actisense” is a registered trademark of Active Research Limited.
The NGT-1-ISO enables software
certified to work with the Actisense
interface standard to talk to devices
on an NMEA 2000 network.
NMEA 2000 network data is freely
available to any Actisense certified
PC software to display.
As an NMEA certified firewall, the
NGT-1 allows NMEA 2000 data to be
sent from the PC to control any
NMEA 2000 devices on the network.
The isolating ISO-Drive connection
of the NGW-1-ISO makes it one of
the safest ways to connect your
computer to an NMEA 2000 network.
Just connect and relax, knowing that
Actisense has it secured.
Benefits
•All NMEA 2000 instruments on the
network can receive data sent from
compatible PC software
•Compatible PC software can receive
data from any NMEA 2000 instrument
•Electrical isolation separates the two
networks, protecting against ground
loop faults. This creates a protected
computer and a safe installation
•Free Actisense diagnostic software
shows what data and devices are on
the NMEA 2000 network
®