Motion Reference Unit page

The motion reference unit (MRU) measures the roll and pitch movements of the vessel. Some sensor models also measure heave. The information provided by the motion sensor is used by the ST90 system to stabilize the beams.

How to open

This page is located in the Installation dialog box. To open the page, select Installation on the Setup menu.

Prerequisites

The Installation dialog box is not available when your ST90 system is set to Replay mode.

Description

The ST90 system is provided with a built-in motion sensor to provide electronic stabilization of the sonar beams. It is placed inside the Motor Control Unit. For improved operational accuracy, an external motion reference unit (MRU) can be used.

  • External: Use the Motion Reference Unit page to define the data format and the communication port used to import motion information from an external sensor.
  • : Use the internal sensor.

The external sensor must be connected using a serial communication line. If you don’t have any available COM ports you must first release one on the I/O Setup page. Make sure that you do not put the same COM port to other use on the I/O Setup page.

Tip:

If the sensor is malfunctioning the input can be disabled.

  • Select None to disconnect the ST90 system from both external and internal motion sensors.
  • The Stabilization function allows you to enable or disable the input from the motion sensor. This function is opened from the Setup menu.

Details

Source

Select Internal to use the built-in motion sensor. Select External to use a third-party motion sensor.

Sensor
  • External: Select the datagram you want to use
  • : Select the sensor you want to use.

Select None to disconnect the ST90 system from both external and internal motion sensors.

The following options are available:

  • EM3000 LAN: This is the default setting. The Hull Unit Control board processes the sensor data.
  • Hull Unit Control: This is the recommended setting. The Hull Unit Control board provides unprocessed sensor data. The sensor data processing takes place in the Processor Unit.

The Hull Unit Control board is located in the lower right corner of the Motor Control Unit. Its primary purposes are:

  • It controls the transducer's hoisting and lowering operations and provides their status.
  • It reads the built-in motion sensor output and promptly transmits this crucial data to the Transceiver Unit.
  • It receives error reports from the hull unit sensors and sends these to the Processor Unit to generate a message.
Note:

You can only select unprocessed sensor data if the Hull Unit Control board software supports this feature. The software version must be 1.3.5 or later. Use the Hull Unit page to read the software and firmware versions from the Hull Unit Control board.

Protocol

This text reflects the chosen datagram format. The term datagram has been defined as follows:

A self-contained, independent entity of data carrying sufficient information to be routed from the source to the destination computer without reliance on earlier exchanges between this source and destination computer and the transporting network.

https://tools.ietf.org/html/rfc1594, April 2016

Interface

This text reflects the interface format you are using.

COM Port

This setting is only available if you use a serial line to interface your sensor. Select COMx to connect to the external motion sensor. "COMx" is the serial port to which the motion sensor is connected.

Baud Rate

This setting is only available if you use a serial line to interface your sensor. Use this setting to specify the baud rate ("speed") for the serial communication.

LAN Port

This setting is only available if you use the local area network (LAN) to interface your sensor. The text identifies the local area network (LAN) port in use on the remote device. The information is provided for reference purposes. You can not change this information.

IP Address

This setting is only available if you use the local area network (LAN) to interface your sensor. The text identifies the IP Address in use on the remote device. The information is provided for reference purposes. You can not change this information.

Status

The current status of the sensor communication is shown. "Not connected" means that the input from the sensor is missing. A message like this (example) verifies that the ST90 system is connected to the built-in motion sensor:

Connected to 192.168.1.30 ST90 Beamformer

Related functionality

Stabilization

The Stabilization function allows you to enable or disable the input from the motion sensor. If you disable the input from the sensor, the beams will not be compensated for pitch and roll movements. This function is opened from the Setup menu.

Hull Unit

Use the Hull Unit page to read the software and firmware versions from the Hull Unit Control board. This page is located in the Diagnostics dialog box.