MRU Compact

The MRU Compact is a small-footprint unit with an easy installation process, supporting various communication protocols and featuring a dust and splash-proof design.

MRU Compact

Product overview

The NORSUB MRU Compact is a small, yet accurate motion reference unit that is easy to install due to its passive Power over Ethernet (PoE) interface. A regular RJ45 Ethernet connector is used for both power and communication so that any cat5e cable can be connected. This makes installation fast and cabling costs low.

The MRU Compact is configured via Ethernet (TCP) and measurements data can be acquired from UDP messages, Modbus TCP or Ethernet/IP.

The MRU Compact dust and splash proof and is suitable for mounting indoors or inside a control box.

The MRU Compact comes in three different versions: 3000, 6000 and 9000 models to accommodate for different accuracy requirements and budgets.

The MRU Compact is also available in an inclinometer version of the MRU Compact that does not include Heave/Surge/Sway outputs.

High Accuracy

High accuracy roll, pitch and heave, even in irregular sea states.

Power over Ethernet

RJ45 or RJ50 connector with Passive Power over Ethernet (PoE) makes installation easy and cabling costs low.

Very Compact

Low weight and small footprint enable installation almost anywhere.

Specifications

Download product brochure

Casing

Environment

IP65

Casing material

Marine Anodized Aluminum 6061-T6

Dimensions

120 x 57 x 53 mm

Weight

0.55 kg

Interfacing

Connector

Compact: RJ45 with passive POE
Compact RJ50: 10-pin RJ50 with passive POE

Ports

Compact: Ethernet
Compact RJ50: Ethernet & RS-232 / Ethernet & RS-485 / Ethernet & PPS

Communication

Compact: TCP, UDP, Modbus TCP, ethernet/IP
Compact RJ50: TCP, UDP, Modbus TCP, ethernet/IP, Serial, Modbus RTU

Output frequency

0-100 Hz

Performance

Roll & Pitch

3000 series: 0.05°
6000 series: 0.02°
9000 series: 0.01°
RMS (dynamic & static)

Heave (real-time)

5.0 cm or 5.0 %
Whichever is greater for 0 to 25 s periods, valid for irregular motions in real sea conditions

Heading (optional)

± 0.5 °
Magnetic heading

Range

Rotation speed

3000 series: ± 150 °/s
6000 series: ± 450 °/s
9000 series: ± 450 °/s

Acceleration

± 3 g (3000 series) / ± 4 g (6000 series) / ± 10 g (9000 series)

Heave

± 50 m

Roll / Pitch / Yaw

± 180 ° / ± 90 ° / ± 360 °
(no limits)

Output frequency

0 - 100 Hz
(adjustable output frequencies)

Gyro output

Scale factor error

0.2 % max/min

Angular rate noise

3000 series: 0.050 °/s RMS
6000 series: 0.025 °/s RMS
9000 series: 0.015 °/s RMS

Acceleration output

Acceleration noise

3000 series: 0.0025 m/s2 RMS
6000 series: 0.0020 m/s2 RMS
9000 series: 0.0015 m/s2 RMS

Acceleration accuracy

0.01 m/s2 RMS

Power & interface

Power consumption

6 W

Supply voltage

9 - 36 V DC (24 V nominal)

Internal storage

32 GB

Data protocols

Custom NMEA, ASCII and Binary, Atlas, Gyrocompas 1, Ifremer Victor, MDL, NORSUB 1-8, Simrad EM 3000, SMCA, SMCC, Tokimek PTVG, RDI ADCP, TSS1 and many more.
Read more

Configuration protocols

GET/SET through telnet, serial port and MRU configurator.
Read more

Time synchronization

Sync to host PC, Sync to NTP server, Sync to PPS

Features

PPS

PPS time synchronization

Aiding

Heading and velocity aiding
(on request)

Environmental specifications

Temperature range

Operating: -40 to +85 °C
Storage: -40 to +85 °C

Electromagnetic compatibility

IEC 60945/EN 60945
(immunity/emission)

Vibration

IEC 60945/EN 60945

Max shock

2000 m/s2 (half-sine 0.5 msec)
non-operational (10 ms peak)

MTBF (computed)

100 000 h

Easy to use

All Norwegian Subsea Motion Reference Units (MRUs) can be easily configured using the MRU Configurator (free of charge).

Simply define the communication ports and protocols as well as the MRU mounting orientation and location, and you are ready to go.

The MRU Configurator is also a great tool to monitor the outputs in real-time, plot the variables, check the on-board diagnostics and update the MRU firmware.

Read more about the MRU Configurator

Some of the applications where our MRU Compact are used

Ship Motion Monitoring

Precise motion measurements are essential for vessel digitalisation, supporting fuel optimisation, route planning, cargo safety and structural health.

Active Heave Compensation

Accurate measurement of vertical motion at the crane tip or winch is crucial for the operation of Active Heave Compensated (AHC) cranes and winches.

Motion Compensated Gangways

Accurate measurements of all 6 degrees of freedom are essential for the automatic motion control of gangways.

Dynamic Positioning

Dynamic positioning (DP) of vessels necessitates roll and pitch compensation of the GNSS antenna to ensure accurate positioning of the ship's control point.

Helideck Monitoring

Accurate measurement of roll, pitch, and heave motions is crucial for assessing the safety of helidecks during helicopter landing and take-off operations.

Stabilising Fins

Stabilising fin and roll damping systems rely on motion sensors to accurately measure the roll motions of a ship.

All applications

Trusted by industry leaders

Over 1200 Norwegian Subsea Motion Reference Units are in operation world-wide on over 600 vessels, floating and subsea structures.

Some selected customer references.

Where our MRUs are used

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