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 five 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-fitted four-core screened
cable for the NMEA 2000 connection, fitted with a
male micro-fit 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
five way screw terminal block is provided within the
NGT-1 to allow easy connection, along with a spare
cable gland that should be fitted 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 specification and be no longer
than 6 metres (maximum drop length).
2.
NMEA 2000 indicator LED
This LED flashes 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 flashes 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
2
5
4
