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© 2009 Active Research Limited
Figure 1
shows an internal view of the USG-1 Printed
Circuit Board (PCB). The USG-1 has screw-terminal
“Phoenix” type connectors with a pre-installed cable.
The Phoenix-style connectors are provided for use when
the customer needs to use their own cable.
1.
An NMEA 0183 input.
Two screw-terminal Phoenix-style connectors are
provided to connect the NMEA 0183 input.
All NMEA 0183 inputs are of the differential Opto-
isolated type and use the unique
Actisense
low
current drain circuitry (2mA @ 2.0v) to conform in
full with the NMEA 0183 marine electronic device
network communication standard. They are also
flexible enough to interface to most fully and partially
compliant NMEA 0183 devices.
2.
An NMEA 0183 ISO-Drive output.
Three screw-terminal Phoenix-style connectors are
provided to connect to the NMEA 0183 ISO-Drive
output.
The NMEA 0183 output comprises three connections:
‘
+
’, ‘
-
‘ and ‘
Ground (GND)
’ and conforms in full to
the NMEA 0183 standard. This allows the USG-1 to
interface to various different devices that require any
combination of these outputs.
Note: The connection marked “GND” on the
ISO-Drive output is not USB or PC ground, it
is connected to the isolated ground of the ISO-
Drive circuit.
In most installations, this 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 NMEA 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.
Actisense supply a four core screened cable pre-wired
to the Phoenix terminal blocks that will be sufficient
for most installations. The colour codes used for this
cable are:
Wire colour
Function
Shield / Screen
ISO-Drive OUT Ground
Blue
ISO-Drive NMEA OUT B/-
White
ISO-Drive NMEA OUT A/+
Black
OPTO NMEA Input B/-
Red
OPTO NMEA Input A/+
The cable shield (screen) connection is connected
inside the USG-1 to the ISO-Drive output ground. As
mentioned, In most instances, leave this disconnected,
although it is possible to connect to the target system
ground as it is fully isolated.
3.
A micro-connector to connect to the supplied
USB type A terminated cable.
This connector should not normally be removed:
it is installed at the factory and is not customer
serviceable.
4.
An indicator LED - USB
This LED flashes when data is sent from or received
from the USB side of the USG-1. It can be clearly
seen through the USG-1’s translucent lid when the
case is closed.
5.
An indicator LED - NMEA 0183
This LED flashes when data is sent from or received
from the NMEA 0183 side of the USG-1. It can be
clearly seen through the USG-1’s translucent lid
when the case is closed.
1
2
USG-1 connections
Figure 1 – Inside the USG-1 case
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3
1
2
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Summary of Contents for USG-1-B-422
Page 2: ......
