Robust, versatile and accurate for the marine industry
High performance data in all dynamic environments delivered in an IP66 or IP68 titanium casing

Marine Motion Sensors

Motion Reference Unit SMC-10
SMC-00 & SMC-10
Roll, Pitch, Heave, Velocities and
Accelerations Marine Motion Sensors

Model Roll/Pitch Heave
SMC-007 0.12° RMS N/A
SMC-008 0.12° RMS 5cm or 5%
SMC-106 N/A 5cm or 5%
SMC-107 0.03° RMS N/A
SMC-108 0.03° RMS 5cm or 5%

Ideal for DP, AHC and Helidecks

Development for over 20 years has produced a Motion Reference Unit that meet the requirements for the Dynamic Positioning systems DP, Active Heave Compensated winches AHC, Helideck Monitoring System as well as other various Roll, Pitch and Heave motion applications.

The SMC Motion Reference Unit data is suitable for any marine operation that requires attitude determination and provides accurate motion measurements in dynamic environments. The SMC MRU Generation 4 is available in two ranges, the SMC-00 Range and the SMC-10 Range.


MRU Helideck

Technology and Kalman filter processing

High performance Accelerometers and tactical grade rate Gyroscopes used in the SMC MRUs provides excellent performance and reliability with low noise and high accuracy.

The Gyroscopes and Accelerometers are mounted in all three axis. The sensing data signals are processed in parallel with Kalman filter inside the motion reference unit multi-core processor. This provides output data for acceleration, attitude and angles with limited influence from accelerations, noise and other inaccuracies.

Heave is computed from integration of the acceleration into a linear position. The integration is further processed and filtered for an accurate heave measurement during dynamic environment.

MRU Functional Diagram

Configuration with PC Software & Built-in Web Interface

The MRU is supplied with a junction box, selected cables and a windows-based Configuration Software. To enable a quick and easy device setup connecting the supplied Ethernet cable allows configuration from the built-in webserver using a standard Web browser over Ethernet. The supplied SMC Configuration software allows for easy configuration via Ethernet and Serial.

COM1 RS232 Bi-Directional
COM2 RS422 Bi-Directional
COM3 RS232 Bi-Directional
COM4 RS232 Bi-Directional
Ethernet 100 mBit TCP/IP, UDP and Modbus
Analog output V or mA with remote converter
Output rate 1 to 200Hz
Baud rates 4800 to 230400bps

MRU Communication

The SMC MRU’s are equipped with 1x 100mBit Ethernet port and 4x Serial ports. COM3 and COM4 can be user configured as either 2x RS232 or as 1x RS422.

The Ethernet port can be configured for up to 20 output channels with its own setting. Communication can be done over UDP, TCP or Modbus formats.

Each serial and ethernet output channel is individually configured with Output protocol selection, Output Rate and selection of one of the three possible user defined measurement points.

Output strings

A wide selection of SMC protocols and internationally recognized marine industrial protocols are available as standard to select from such as PSMCC, TSS1, EM3000 and PRDID to name a few.

Additionally, the SMC MRU offers the ability to create a custom protocol within the configuration software selecting from the available parameters with a unique protocol header. This feature can be used for custom or replicating other industry or discontinued protocols.

Output strings

Output strings

AHC integration

Unique to the SMC MRUs is the SMC Active heave compensation AHC encoder feedback.

Developed in conjunction with Bosch Rexroth drives the SMC AHC system accepts dynamic crane encoder position data, enabling continual calculation of the selected active heave measurement data to provide real-time motion compensation during critical marine crane operations.

Modbus TCP/IP communication implementation developed with ABB enables seamless integration with the ABB ACS880 drives for new and Retrofit AHC applications.

Titanium Enclosure

SMC's product development and design philosophy is to produce technologically advanced, durable yet uncomplicated products.

The SMC MRUs are produced in Titanium suitable with its high strength, low density and corrosion resistance for the Marine environments the motion reference unit works in.

IMU 108 Dimensions IMU 108 Dimensions

SMC-008 Dimensions SMC-008 Dimensions

MRU Ranges

The different SMC Motion Reference Units have similar functionality and communications with different performance specifications. The SMC-10 range has higher performance sensing elements for greater accuracy than the SMC-00 range.

To select which sensor is suitable for an application depends upon the Accuracy Required, international standards specified, the dynamics of the operational environment and the projects budget.

Output strings

Option for IP66 and IP68

The SMC MRUs are available as IP66 surface or IP68 submersible versions. The Surface models of the SMC Motion Reference Units have an IP66 rating for outdoor water protection.

Submersible depth rated IP68 options are available rated for up to 30m depth.

MRU Calibration

Each motion sensor is calibrated individually and the readings from the accelerometers and angular rate gyroscopes are adjusted for offsets, alignment, linearity and temperature variations, to ensure they meet the performance specifications.

We thoroughly test the MRUs in our facilities during the calibration process with the use of a rate table with a controlled temperature chamber prior to delivery. The calibration is performed in a 2-axis rate table with a temperature-controlled chamber in a fully automated process.

Technical specifications

Model features SMC-007 SMC-008 SMC-106 SMC-107 SMC-108
Roll/Pitch Yes Yes N/A Yes Yes
Accelerations Yes Yes N/A Yes Yes
Heave N/A Yes Yes N/A Yes
Performance Anglular Accuracy
@ ±5° simultaneous roll and pitch
0.12° RMS 0.12° RMS N/A 0.03° RMS 0.03° RMS
Angular range Roll/Pitch ±30° ±30° ±30° ±30° ±30°
Heave Accuracy N/A 5cm or 5% 5cm or 5% N/A 5cm or 5%
Acceleration accuracy 0.05 m/s² RMS 0.05 m/s² RMS     N/A     0.01 m/s² RMS 0.01 m/s² RMS
Physical Dimensions

Housing Material
(W x D x H) 134 x 134 x 60mm excl connector
~1 kg
(W x D x H) 134 x 134 x 85mm excl connector

~1.7 kg
Communication Ethernet 100 mBit. TCP/IP, UDP and Modbus
Ethernet not available on submersible units
Com1: RS232 Bi-Directional
Com2: RS422 Bi-Directional
Com3: RS232 Bi-Directional
Com4: RS232 Bi-Directional
Com3 and Com4 can be combined to 1x RS422 from the MRU Configuration Software

Analog output V or mA with remote converter (optional)
Aiding input formats RMC, RMA, VTG, VHW, HDT, HDG
SMC MRU Configuration software included
User selectable Output Protocols
User selectable Output Rate 1-200hz
Environmental Temperature -20° to +55° Celsius, performance below 0°C is 0.1° angle on the SMC-10
Storage Temperature -40° to +65° Celsius
MTBF (computed) 50 000 hours
IP66 as standard; IP68 30 meter depth rated optional
Electrical Power requirements 12 - 30 VDC; 4 W
Standard Complies with the IEC 60945
Warranty & Support 2 Years Hardware & Software Warranty
Free Technical & Hardware support