Important Notices
This device complies with Electromagnetic Compatibility requirements according to EN60945. It must be used with appropriately approved, shielded cables and connectors as per NMEA 0400 for compliance. A declaration of conformity is available at www.actisense.com.
For installations within five metres of a compass, consult the 'Compass Safe Distance' section in the 'Technical Specifications' table.
Technical Accuracy
The information in this document was believed to be correct at the time of production. Active Research Ltd accepts no liability for inaccuracies or omissions. Specifications may change without prior notice. Active Research Ltd is not liable for infringement of third-party rights resulting from the use of information or drawings in this manual.
Trademarks and Registered Trademarks
Actisense® and the Actisense logo are registered trademarks of Active Research Limited (Ltd). All other trademarks are the property of their respective owners. The NMEA® name and logo are copyright held by NMEA, used here by permission.
Fair Use Statement
Manual contents may not be transferred or copied without express written permission from Active Research Ltd. Copyright © 2018 Active Research Ltd. All rights reserved.
Product Registration
Register your product online at: www.actisense.com/product-registration/. Your product package includes a six-digit serial number, found below the barcode. Registration assists Actisense Support.
Product Disposal
Dispose of this product in accordance with the WEEE Directive ⚡. Take it to a registered establishment for electronic equipment disposal.
Product Guarantee
This product includes a three-year 'return to base' guarantee. For faults, consult the Troubleshooting Section of the User Manual before contacting support. All electronic equipment installations must follow NMEA 0400 specifications. Battery or power supply connections must meet mandatory local safety requirements.
Introduction & Features (EMU-1)
The Actisense EMU-1 is a specialised analogue to NMEA 2000 Gateway that converts analogue engine gauge/sender data into NMEA 2000 data. It can monitor engine parameters like temperature, pressure, RPM, and fluid levels for up to two engines. The EMU-1 features a PC-based configuration tool, requiring an Actisense PC to NMEA 2000 Gateway (NGT-1) for setup.
Installation Guide
This guide provides essential information for the OPTO-4 installation. For the latest user manual, software, and resources, visit www.actisense.com/OPTO-4.
Overview
The NMEA 0183 specification (version 2.0 onwards) requires an RS422 "differential" connection. Listener inputs should be electrically isolated to prevent ground loop damage, common in marine environments. Standard PC RS232 inputs are not isolated or differential. The OPTO-4 enables a differential NMEA 0183 device to connect correctly to a PC, providing electrical isolation.
Powering the OPTO-4
The OPTO-4 draws power from the RS232 TX line and handshaking lines RTS and DTR. External power is usually not required when connecting to a PC. For systems unable to provide power on these lines, a DC power supply (9V to 15V) can be used via a male 9-pin D-type connector. For most external power needs, only positive power is required: connect positive power (9V to 15V) to pin 7, and power ground to pin 5 and pin 4. Some installations may need both positive and negative supplies: connect positive power (9V to 15V) to pin 7, power ground to pin 5, and negative power (9V to 15V) to pin 4. Note: Connecting an external power supply may create a ground loop; ensure the supply ground is at the same potential as the RS232 device ground before connecting.
Note: Listeners using ground for the -ve data line (e.g., RS232 or older NMEA 0183 V1 devices) may not be suitable. There is no isolation between the RS232 port and the Blue wire. Connecting the Blue wire to the Listener's ground connects it to the PC's ground. Connecting the OPTO-4 Blue and Black wires together negates the OPTO-4 isolation.
Connecting to an RS232 Port (non PC)
Connections and power options are the same as for a standard RS232 9-pin D-type connector, as described in the 'Connecting to a PC' sections.
Connecting a Serial to USB Converter Cable
Connecting to a USB to Serial converter cable is similar to connecting to a standard RS232 PC serial port. Refer to the 'Connecting to a PC' section, replacing 'PC' with 'converter cable'. Not all converter cables provide power on handshaking lines; refer to 'Powering the OPTO-4'.
Connection Diagram
The connection diagram illustrates the physical interface of the OPTO-4. It shows the female DB9 connector on the OPTO-4, with labels for the wires extending from it: White wire (RS232 PC Tx), Blue wire (RS232 PC Ground), Bare wire (Cable Shield), Red wire (NMEA Listener A/+), and Black wire (NMEA Listener B/-).
DB9 Pin Out Table
| DB9 Pin Number | Function |
|---|---|
| Pin 1 | No Connection |
| Pin 2 | PC Rx / OPTO-4 Tx |
| Pin 3 | PC Tx / OPTO-4 Rx |
| Pin 4 | PC DTR / OPTO-4 Power |
| Pin 5 | GND |
| Pin 6 | No Connection |
| Pin 7 | PC RTS / OPTO-4 Power |
| Pin 8 | No Connection |
Connecting to a PC
The OPTO-4 features a female 9-pin D-type connector for direct connection to a standard RS232 PC serial port.
Connecting a Talker to the PC
For NMEA 0183 version 2.0 or later:
- Connect the OPTO-4 Red wire to the NMEA 0183 Talker A/+.
- Connect the OPTO-4 Black wire to the NMEA 0183 Talker B/-.
For RS422 or RS485 devices not specifically NMEA 0183, connect as above.
For RS232 devices (NMEA 0183 or not):
- Connect the OPTO-4 Red wire to the Talker RS232 Tx or +ve data.
- Connect the OPTO-4 Black wire to the Talker ground.
Connecting a Listener to the PC
For NMEA 0183 version 2.0 or later (Listener must have an isolated input):
- Connect the OPTO-4 White wire to the Listener A/+.
- Connect the OPTO-4 Blue wire to the Listener B/-.
NMEA 0183 Wiring Diagram
The NMEA 0183 wiring diagram details the color-coded connections of the OPTO-4. The Red wire is for connecting to the OPTO-4 Listener Rx A/+ (which corresponds to the Talker Tx A/+ or Data). The Black wire connects to the OPTO-4 Listener Rx B/- (which corresponds to the Talker Tx B/- or Ground). The Bare wire serves as the Shield. The White wire connects to the OPTO-4 Talker Tx A/+ (which corresponds to the Listener Rx A/+ or Data). The Blue wire connects to the OPTO-4 Talker Tx B/- (which corresponds to the Listener Rx B/-).
