User manual

Page 10© 2009 Active Research Limited
OPTO Inputs
The differential opto-isolated inputs are designed to handle
a variety of NMEA 0183 device output specications.
Please determine (from device manufacturer’s
information) if the device(s) required to be connected
to the Actisense NDC-4 conforms in full to the NMEA
0183 network communication standard. If it does not, the
exible Actisense NDC-4 inputs should still be capable of
interfacing with the device, though this is not guaranteed.
The diagram above shows a typical installation with both
fully compliant NMEA devices with differential inputs/
outputs, and non-differential output devices.
NMEA Talker devices 1, 2 and 4: These devices
conform in full to the NMEA 0183 standard. Devices 1
and 4 share the same connection ID’s as the Actisense
NDC, so connection is a simple matter of matching
the ID’s (refer to gure 2). Device 2 uses the RS485
convention connection ID’s. Simply connect ‘A‘ to ‘+/A‘
and ‘B’ to ‘ -/B’ (refer to gure 2).
NMEA Talker device 3: This device does not conform
completely to the NMEA 0183 standard. However, by
connecting ‘+‘ to ‘+/A‘ and its ‘G/Ground’ to the NDC “-
/B” the NDC should receive the NMEA data correctly.
ISO-Drive Outputs
The ISO-Drive outputs are capable of driving up to 10
NMEA 0183 fully compliant listening devices, or a mixture
of NMEA 0183 devices and a Personal Computer (PC)
communication port. However, if you wish to maintain
isolation between all devices, then only one listening
device should be connected to an ISO-Drive output.
NMEA Listener device’s B and C: These devices
conform in full to the NMEA 0183 standard and their
connection ID’s match that of the NDC.
Personal Computer: Whilst the OPTO IN 0 and ISO-
Drive 0 provide a bi-directional RS232 compatible
port for connection to a PC, the ISO-Drive 1 output
is also capable of being read by a PC’s RS232 port.
Simply connect ‘+/A’ to ‘Rx’ and ’-/B’ to ‘G/Ground’ on
a standard D-type (probably male) connector.
NMEA Listener device A: This device does not
conform in full to the NMEA 0183 standard. However,
by connecting ‘+/A‘ to ‘+‘ and ‘-/B’ to ‘G/Ground’ the
device should be able to receive the NMEA data
correctly, though this is not guaranteed.
Note:
1. Wire colours are for guidance only.
Connecting to NMEA devices
Figure 2 – NMEA 0183 connections
NMEA DATA COMBINER
99999
NDC-4-A-USB
NMEA
Talker 3
+
G
NMEA
Talker 1
+
-
NMEA
Talker 2
A
B
NMEA
Talker 4
+
-
Personal
Computer
Rx
G
NMEA
Listener A
+
G
NMEA
Listener B
+
-
NMEA
Listener C
A
B