
OCTANS – User Manual
MU-OCTANS-AN-020 Ed. D – November 2015
1 INTRODUCTION
This document is the OCTANS User Manual. It provides information on OCTANS
specifications, mechanical and electrical interfaces.
OCTANS is both a fiber-optic survey-grade IMO-certified gyrocompass and a Motion
Reference Unit for marine applications. OCTANS provides true-heading, roll, pitch, yaw,
heave, surge, sway, rates of turn and accelerations even in highly volatile environments.
•GPS
•Speed log
OCTANS can output two distinct heave measurements:
•Real Time Heave which provides heave in real time mode.
•Smart HeaveTM which provides a measurement of heave with a 100s fix delay.
To avoid the effect of transient vehicle/vessel movement on heave measurement, you can
define the position of the center of gravity (COG) of the vehicle/vessel. In this case,
OCTANS will compute heave at the COG and add the heave induced by lever arms from
the COG to external monitoring points. For more details see:
•Inertial Products – Application Note - Installation and Configuration of AHRS and INS
for Seabed Mapping Measurements (Ref.: MU-HEAVAPN-AN-001)
•Inertial Products – Web-based Interface User Guide (ref.:MU-INSIII-AN-021)
Your OCTANS internal clock can be synchronized with data coming from an external
reference clock (e.g. GPS clock). In this case, time is synchronized with input coming from
the selected interface with appropriate protocol.
For more details see Inertial Products – Web-based Interface User Guide (ref.:MU-INSIII-
AN-021).
To maintain the product watertightness and EMC specification (see Technical
Specifications for level applicable to your product), it is mandatory to use the provided
connectors and adequate cables. If connector is not used, then it must be
protected/closed with the supplied screwed dummy plugs.
Do not expose to water or humidity if an “office type” Ethernet connector is directly
plugged into OCTANS, use instead, the provided Ethernet connector with its backshell.
When applicable (i.e. IMO Product), OCTANS unit complies with the requirements of the
IEC 60945 standard, including §4.5: interference. As recommended in §4.5.3 - Compass
Safe distance, the minimum safe distance at which OCTANS shall be mounted from a
standard or a steering magnetic compass is 5 meters.
Heave
measurement/
Center of
Gravity of the
vehicle (COG)
Waterproof and
Electroma-
gnetic
Compatibility
consideration