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Signature VM Operations Manual
N3015-026500 | V 1.1
V 1.4
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NORTEK
Table of Contents
Table of Contents ............................................................................................................................................ 2
1 System Overview ..................................................................................................................................... 6
1.1 Signature AD2CP Sensor ................................................................................................................ 7
1.2 GNSS Receiver ............................................................................................................................... 7
1.3 Data acquisition system ................................................................................................................... 8
2 Getting Started ......................................................................................................................................... 9
2.1 Checking the Inventory .................................................................................................................... 9
2.2 Signature VM Software .................................................................................................................... 9
2.3 Interface ........................................................................................................................................... 9
2.3.1 24VDC Version ............................................................................................................................ 9
2.3.2 AC version ................................................................................................................................. 10
2.4 Connecting the parts ..................................................................................................................... 10
2.4.1 Connecting the Signature Sensor .............................................................................................. 10
2.4.2 GNSS Connection ..................................................................................................................... 13
2.4.3 Computer connections ............................................................................................................... 15
2.4.4 Power On ................................................................................................................................... 16
2.4.5 Power Off ................................................................................................................................... 16
2.4.6 Connecting to the Computer ...................................................................................................... 16
3 Acquisition Software ............................................................................................................................... 19
4.1 Checking the system ..................................................................................................................... 21
5 Measuring ............................................................................................................................................... 25
5.1 Configuration ................................................................................................................................. 25
5.2 Start the measurement .................................................................................................................. 27
5.3 Measuring and Display .................................................................................................................. 29
5.4 Status ............................................................................................................................................. 29
5.5 Track display .................................................................................................................................. 30
5.6 Echograms ..................................................................................................................................... 32
5.7 Keyboard Shortcuts ....................................................................................................................... 32
5.8 Error Messages ............................................................................................................................. 32
6 Offsets .................................................................................................................................................... 34
6.1 Vessel Coordinate system ............................................................................................................. 34
6.2 Horizontal and vertical offsets ....................................................................................................... 35
6.3 Orientation of the GNSS and Signature ........................................................................................ 37
7 Output ..................................................................................................................................................... 39
7.1 NMEA Output ................................................................................................................................. 39
7.1.1 $SDDBT –Echosounder- Depth Below Transducer .................................................................. 39
7.1.2 $SDGGA - Global Positioning System Fix Data ........................................................................ 40
7.1.3 $SDVTG - Track made good and Ground speed ...................................................................... 40
7.1.4 $PNORI1 – General Information ............................................................................................... 40
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7.1.5 $PNORS1 – Sensor Data .......................................................................................................... 42
7.1.6 $PNORCV – Velocity data per Cell ........................................................................................... 42
7.1.7 $PNORC1 – Velocity data per Cell ............................................................................................ 42
7.1.8 $PNORBT4 – Speed over ground and depth ............................................................................ 43
7.1.9 $VDVDR – Current Speed and Direction .................................................................................. 43
8 Installation .............................................................................................................................................. 44
8.1 Instrument orientation .................................................................................................................... 44
8.2 Mounting Considerations ............................................................................................................... 44
8.2.1 Bubbles ...................................................................................................................................... 44
8.2.2 Grounding .................................................................................................................................. 44
8.2.3 Ship movements ........................................................................................................................ 45
8.2.4 Ship generated flow fields ......................................................................................................... 45
8.2.5 Over the Side Mounting ............................................................................................................. 46
9 Maintenance ........................................................................................................................................... 50
9.1 Signature Sensor ........................................................................................................................... 50
9.2 Biofouling ....................................................................................................................................... 50
9.2.1 Antifouling Paint and patches .................................................................................................... 50
9.3 Instrument Care ............................................................................................................................. 50
9.4 Connector Care ............................................................................................................................. 51
9.5 Cable Care ..................................................................................................................................... 51
10 Troubleshooting ...................................................................................................................................... 52
10.1 Remote Support through TeamViewer .......................................................................................... 52
10.2 Communication .............................................................................................................................. 53
10.2.1 Cable ......................................................................................................................................... 53
10.3 Power ............................................................................................................................................. 53
10.3.1 Interface does not switch on ...................................................................................................... 53
10.3.2 Power to the Signature sensor .................................................................................................. 53
11 Computer configuration .......................................................................................................................... 54
12 GNSS ..................................................................................................................................................... 56
12.1 Filter setting ................................................................................................................................... 56
12.2 Increasing the accuracy using RTK (NTRIP) ................................................................................ 56
13 Glossary ................................................................................................................................................. 58
14 Connector Pin Configurations ................................................................................................................ 60
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Preface
This manual is designed to help users of Signature VM to get familiar with the system. The manual includes
chapters covering how to get the system up and running as quickly as possible, functional testing, software
information, and tips for maintenance and troubleshooting.
This manual is for the Signature VM System. For details on the individual instruments please refer to the
specific manuals that come with the sensor itself.
Nortek WEB
At our website, http://www.nortekgroup.com, you will find technical support, user manuals, and the latest
software and firmware. General information, technical notes and user experience can also be found here.
Your feedback is appreciated
If you find errors, omissions or sections poorly explained, please do not hesitate to contact us. We
appreciate your comments and your fellow users will as well.
Contact Information
We recommend first contacting your local sales representative before the Nortek main office. If you need
more information, support or other assistance, you are always welcome to contact us or any of our
subsidiaries by email, phone or fax.
Email mailto:support@nortekgroup.com (for technical support questions)
Phone: +31 20 6543600
You can also write us at:
Nortek BV
Schipholweg 333a
1171PL Badhoevedorp, The Netherlands.
Manual Revision - N3015-026500
Version
Date
Supports Software
version
Notes
Preliminary
01.02.2018
1.2
Version 1
11.04.2018
1.5
Version 1.1
11.09.2018
1.6
Interface Version 2 (1/2 19 inch)
Version 1.2
21.12.2018
1.7 Version 1.3
29.03.2019
1.8 Version 1.4
11.07.2019
1.9
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Health and safety
The system is designed and produced to comply with the council directive of
2014/108/EC relating to electromagnetic compatibility. The design is according to RoHS
II directive 2011/65/EU
The mark on the left is in compliance with the Waste Electronic Equipment Directive
2012/19/EU (WEEE). It is a requirement NOT to dispose the equipment as unsorted
municipal waste but use the return to collection systems according to local law, or return
to the Nortek facilities.
Relevant plastic parts on the Signature sensor are marked for end-of-life recycling
(Directive 2008/98/EC on waste)
Use the following safety guidelines to help ensure your own personal safety
and to help protect your equipment and working environment from potential damage
General Power Safety for the 4411 Interface unit and Computer
Observe the following guidelines when connecting your equipment to a power source:
• Check the voltage rating before you connect the equipment to an electrical
outlet to ensure that the required voltage and frequency match the available
power source.
• Do not plug the equipment power cables into an electrical outlet if the power
cable is damaged.
• To prevent electric shock, plug the equipment power cables into properly
grounded electrical outlets. Do not use adapter plugs that bypass the grounding
feature or remove the grounding feature from the plug or adapter.
• Do not operate your equipment with any cover(s) removed.
• Unplug this apparatus during lightning storms or when unused for long periods
of time.
• Do not expose the unit to rain or an environment where it may be splashed by
water or other liquids, as doing so may result in fire or electric shock.
System Safety
• The system is designed to be used on a moving vessel. Make sure that all parts
are well secured, and nothing can come loose when exposed to heavy
vibrations or sudden movements which may occur aboard a vessel.
Safety when installing and operating the Signature VM Sensor
• When mounting the Signature sensor on any vessel or other platform, be careful
to follow proper precautions and safe-work procedures as applicable to working
with medium-weight, long, unwieldy material (work-gloves, helmet, and if onboard, possibly life-jacket).
• Ensure that nothing rests on your equipment's cables and that the cables are
not located where they can be stepped on or tripped over.
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1 System Overview
The Signature VM system is a highly integrated system with the sole purpose of accurately measuring
vertical profiles of the water’s velocity and direction from a moving platform.
Velocity of the water is measured using a Signature series sensor. The Signature sensors are advanced
five-beam current profiling systems. Built on the entirely new AD2CP platform, they are designed for
unprecedented performance in high energy turbulent environments. The Signature also measures its own
speed and direction across the bottom of the channel using a technique known as ‘bottom tracking’
Position and movement of the moving platform (usually a vessel) is recorded using a high precision Global
Navigation Satellite System (GNSS) receiver, which also provides accurate timing. By combining the
measured movements from both the GNSS and bottom track it is possible to correct the measured water
velocities for the movement of the platform itself.
A dedicated computer system with Signature VM software collects the data, takes care of accurate timing
and continuously monitors the quality of the data. Since no additional data from any external sensors is
required and the computer comes fully configured, the whole system is basically ‘Plug and Play’
Figure 1 Complete system overview
Signature VM Computer
PoE
adapter
Ethernet
Switch
Eth1
Pwr (90-
230VAC)
Interface Box
Signature Sensor
GNSS
User supplied Laptop or PC
with Remote Desktop
90 - 260VAC
48 VDC
PSU
LED Driver
48 VDC
DC/DC
12-36 VDC
DC Option
AC Option
90 - 230VAC
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1.1 Signature AD2CP Sensor
The figures below show the Signature1000 system but can be easily translated to the Signature500. The
Signature1000 and Signature500 sensor heads have five acoustic transducers, four slanted at 25 degrees
from vertical, and a fifth vertical beam. For dimensions, please refer to the specific instrument data sheet,
available for download from our website.
The pressure sensor, temperature sensor and LED light are all visible from the outside. Note also the beam
configuration, with beam one pointing in the positive X-axis (see the engraved axis definition on the head)
Figure 2 Signature Transducers and sensors
Power requirements:
DC input: 12-48 (Sig500/1000)
For more details on the Signature Sensor itself, please refer to the Signature Manual, as available on the
Nortek group website: http://www.nortekgroup.com/manuals-quick-guides
1.2 GNSS Receiver
Figure 3 GNSS - Receiver
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The Advanced Navigation Global Navigation Satellite System (GNSS) receiver is a fully integrated, certified
navigation and heading solution. It provides high accuracy position, velocity and heading information and
does not require any calibrations or setup. It can provide accurate heading even during GNSS outages (for
up to 20 minutes). This is possible as a result of the INS (Inertial Navigation System) integration in the unit.
The antenna is equipped with two internal GNNS receivers and its heading is not subject to magnetic
interference. The vessel doesn’t have to move to provide an accurate heading.
The built-in PTP (Precision Time Protocol) server provides an accurate timing reference for the whole
system.
The GNSS is powered through the Ethernet cable.
For more details on the GNSS Sensor itself, please refer to the User Manual, as available on: the Advanced
Navigation Website: https://www.advancednavigation.com/product/gnss-compass You can also check out
the latest firmware release here.
1.3 Data acquisition system
Figure 4 Signature VM Data acquisition and interface
Data is collected using a computer running the ‘Signature VM’ software. The Signature VM interface box
provides all necessary connection and power to the individual instruments. The total system is 19” rack
mountable. It can be controlled using a local keyboard and monitor, or from a remote location over Ethernet.
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2 Getting Started
This chapter deals with installation of the accompanying software, connecting to the instrument and other
information that is important for first time use of the instrument.
2.1 Checking the Inventory
Check the content of the received package against the packing list included in the shipment. Do not hesitate
to contact us if you find any part of the delivery missing.
2.2 Signature VM Software
The Signature VM software is under continuous development, so it is advised to check on a regular basis if
a new version is available. Note that a decent internet connection is required for checking and possible
downloads.
2.3 Interface
The Signature VM interface provides power to the Signature sensor and GNSS and has all necessary
interconnections between the different parts. Two versions are available: an AC version that accepts
standard mains power from 100 to 240 VAC and a 24 VDC version that can take a DC voltage from 12 to 36
VDC
Figure 5 Rear panel connections. AC version
2.3.1 24VDC Version
The 24 VDC version is powered through a 3 Pin XLR connector. Use a suitable power lead with a 3 pin
female XLR connector.(Neutrik model NC3FXX-B)
The unit is reverse polarity protected, so reversing the power lines will not damage it. The supply is fused
using the fuse on the rear-panel.
+
DC Connector on rear panel
1: 2: + 12-34 VDC
3: Shield (to housing)
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The unit will work with any voltage between 12 and 34 VDC, but 24VDC is preferred. When using 12VDC,
current surges of up to 1.5 A may occur, so the required power lines should have a low ohms resistance.
2.3.2 AC version
The AC version can take mains power ranging from 100 to 240 VAC. Power is connected using a standard
IEC mains socket on the rear. The socket contains two 1.6AT fuses.
2.4 Connecting the parts
A Signature VM system basically consists of three parts: a Signature sensor, a GNSS and a computer. The
interface box contains all necessary interconnections and power supplies for the other parts.
Figure 6 Connecting the interface to the PC
Note that only one ethernet port on the PC is configured to connect to the Signature VM Interface. The
system will not work if this is connected to the wrong port!
The second ethernet port may be connected to the local network and is only used to access the internet.
2.4.1 Connecting the Signature Sensor
The Signature sensor is connected through its Ethernet interface. This is the 6-Pin connector on the sensor.
The 8-Pin connector is not used in this configuration and should be fitted with a ‘dummy’ connector.
USB
Ethernet
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Figure 7 Signature Sensor connections
When mating the SubConn connectors pay attention to the following guidelines:
• Connectors must be greased with Molykote 44 Medium before every mating. A small amount of
grease is supplied with the system.
• A layer of grease corresponding to minimum 1/10 of socket depth should be applied to the female
connector
• The inner edge of all sockets should be completely covered, and a thin transparent layer of grease
left visible on the face of the connector
• After greasing, fully mate the male and female connector in order to secure optimal distribution of
grease on pins and in sockets
• To confirm that grease has been sufficiently applied, de-mate and check for grease on every male
pin. Then re-mate the connector
6 pin Ethernet + Power
8-pin Serial
(NOT USED)
Recommended level of grease
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The other end of the power-signal cable has a metal shield Ethernet connector that fits the connector on the
rear of the box. Insert the connector until it clicks into lock. To release the connector, press the ‘PUSH’ lever
and gently pull the connector housing.
The standard Signature cable comes with a simple jack plug. On the interface that power is supplied through
a DC-Power plug with lock-nut. An adapter cable is supplied to connect the standard signature cable to the
interface. Lock it by tightening the nut.
Figure 8 Signature Power and data connection
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2.4.2 GNSS Connection
The GNSS is supplied with a 20 m Ethernet cable. One end has a small plastic connector with a bayonet
lock which goes to the GNSS unit.
When connecting first check the orientation of the Ethernet connector. Then push in while holding the plastic
locking-ring. Push the ring while turning it clockwise until it clicks to lock. It is a bayonet lock, so it should not
need more than a 30~40 degrees rotation. This may take considerable force, and it is best to use the
supplied 'Connector wrench’
Figure 9 Connecting the GNSS connector
The other end of the cable has a large plastic Ethernet connector that fits the one on the rear of the interface
box. This bayonet lock may be difficult to lock when new.
Power to the GNSS is supplied through the Ethernet cable, so no additional power connection is needed
here.
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Figure 10 Connecting the GNSS to the interface
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2.4.3 Computer connections
Next to the GNSS connector is the main Ethernet port and a USB port which have to be connected to the
Signature VM computer.
Figure 11 All interface connections
Power to Signature
Data to Signature
Power and Data
to GNSS
LAN and USB to
computer
Power in
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2.4.4 Power On
Switch the computer on by pressing the main button on the front-panel for a second and then release it. The
interface has a simple ‘ON’ switch and may be switched on before or after switching the computer.
2.4.5 Power Off
When powering the system off, first switch off the computer using the power down menu, or by using the
switch. Then switch off the interface.
2.4.6 Connecting to the Computer
Though it is possible to connect to the Signature VM PC using a keyboard/mouse/monitor, the general idea
is to use a remote desktop connection from a laptop. (Not supplied with the system)
Any computer that can run the Remote desktop client can be used to connect to the system. Remote
desktop clients are available for Windows, Macintosh and Linux.
The client computer can be connected to the Ethernet connector on the front panel of the interface, and
configured as follows.
(note: configuration example shown here for Windows 10)
First make sure the Ethernet adapter is configured for ‘Obtain an IP address automatically’. (Control Panel>Network and Internet->Network Connections)
1
2
NOTE: depending on the computer model, this switch
may look different, or even be in a different position.
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Now connect the client computer to the interface, and then open ‘Remote Desktop’ (Hit the ‘Windows’ key,
and just type ‘remote desktop’)
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The address of the Signature VM PC is fixed to 192.168.100.1. The user name is ‘SurveyVM’. You can now
click ‘Save As’ to save this connection for later.
Click connect. If all is correct, a popup will appear asking for the password. The password is ‘SurveyVM’
Once connected the screen of the Signature VM computer will appear:
IP : 192.168.100.1
User: SurveyVM
Passw: SurveyVM
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3 Acquisition Software
Once everything is connected, start the Signature VM software.
Each window may be moved, rescaled or closed if required. To recover a window, or to reset the screen
layout to defaults, click on one of the four window recovery buttons in the lower left. Clicking the appropriate
button will bring up the related window, or you can click ‘Restore Layout’ to get back to default.
The main task bar is on the left. This contains the controls for starting and stopping the measurement,
changing the settings and replaying the data.
Window recovery buttons
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Figure 12 Taskbar explained
Connect / Disconnect the instruments
Start/Stop the measurement
Instrument connection options
Open a file for playback
Start / Stop playback
Pause playback
Playback options
Start a new recording
Recording details
Start NMEA output
NMEA output settings
Configuration
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4.1 Checking the system
The instrument connection options appear when clicking the ‘three dots’ button in the instruments section of
the task bar.
Make sure the adapter shows ‘SurveyVM Interface’
Click ‘Connect’ to start reading the GPS data. The IP Address and Port box will turn grey and the button text
will change to ‘Disconnect’. Now click on ‘Web page’. This will open the internal web-interface page of the
GNSS Sensor:
Instrument connection options
Type: Advanced Navigation. This is the
dedicated output format of the Advanced
Navigation GNSS.
The second option is ‘Network NMEA’
which may be used if only NMEA
messages are available.
The connection is enabled as the button
now shows ‘Disconnect’
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Figure 13 GNSS WEB interface
It is important that the GNSS is fully functional and has a correct position and heading, so make sure all
markers in the top row are green.
Figure 14 GNSS indicators should be all green
Note that this may take a while, especially after the system has been moved to a different location. Also, the
antenna should have a real clear view of the sky to achieve a faster lock. Refer to section 5 for details on
mounting the GNSS antenna. The map is only visible if the computer is also connected to the internet.
Next select the Nortek Sensor Communication. When the program is started it will automatically search for
any Signature Sensors on the network. In general there will be only one, so when the sensor settings
appear it will show the serial number of the attached sensor.
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Figure 15 Signature Connect settings
Click ‘Connect’ to start the Nortek sensor. The address / serial number box will turn grey and the button text
will change to ‘Disconnect’ and a ‘Start’ button will be available.
There are two checkboxes available, both are generally ticked:
✓ Use PTP: Use the Precision Time Protocol. This is on by default as the PTP signals are generated
by the GNSS receiver. The PTP signal is used to maximize the synchronisation of all instruments.
Uncheck this box if no PTP signal is available, for example when using a different GNSS receiver.
✓ Use default deployment: The measurement configuration of the Signature VM sensor is stored in a
deployment file. If this checkbox is unchecked the software will ask the user to select a specific
deployment instead of the default one that comes with the software.
The example above assumes only one Nortek sensor is connected to the network. If multiple sensors are
connected it is important to know which sensor is actually in use. The ‘Discover’ option only shows the serial
number of the first instrument that is found, so this may be the wrong instrument. In that case it is important
to check that the model and serial number as shown here matches the correct instrument. You can use the
drop-down box to select a different instrument.
If no serial number is shown, click
‘Discover’ to have the software search
for connected sensors.
Click the drop-down box to see the IP-
Address of this sensor, or any other
sensor attached to the network.
Click ‘Connect’ to connect to the
instrument
The connection is established. It
detected a Signature1000 sensor, the
button shows ‘Disconnect’, and the
‘Start’ button is available.
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Once connected, click on ‘Web page’. This will open the internal web-interface page of the Signature
Sensor:
The ‘Status’ panel shows a detailed overview of what is received and what is not.
Figure 17 Status panel with status indicators
The Position, Heading, Speed and Time are provided by the GNSS. If they are all marked red there is no
GNSS data. If only Heading information is missing, there might be a problem with the GNSS measurement
due to bad environmental conditions. When there is data, but the data may be unreliable the indicators will
go Yellow.
RED
YELLOW
GREEN
Position
No Data from GNSS
2D Fix (degraded
accuracy)
3D GNSS Fix
Heading
No Data
Heading from internal
gyro sensors.
Heading from the Dual
antenna.
Data from GNSS:
Position, Heading, Speed and Time
Data from Nortek Signature
Bottom track: Ship Velocity and depth
information
Beam Data: Water flow and direction
Figure 16 Signature WEB interface
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5 Measuring
If everything is configured correctly and working as described in the previous section the measurement may
be started.
5.1 Configuration
Start by checking the configuration and adjust the necessary variables. Click the ‘Configuration’ button to
bring up the settings:
Figure 18 Configuration pop-up window
Usually most settings can stay at their default. Important settings to check:
Setting
Default
Description
Application Settings
Display Units
Metric
Distance and speed on the screen in m/s or Knots and
feet
Project theme
Dark
Display theme, light or dark. The program needs to be
restarted after changing the theme.
Max Recording length
0
Maximum length of a single recording. If set to zero
everything is recorded in a single continuous file. Else
it is split in files of the specified length. The length
should be specified in dd:HH:MM:SS format. Dd is the
number of days, but if not used the time is just entered
in hours minutes seconds.
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Recorder file location
..\Documents\Nortek\
SignatureVM
Where the recorded data is stored.
Show time in UTC
Off (Local time)
Show time and date on the screen in UTC. Does not
change the recorded data which is always recorded
with UTC timetags.
Display Units
Metric
Metric (m/s) or Nautical (knots) on the screen
Data source settings
Clock Source
Auto
Where the clock as used for synchronisation is taken
from. ’Primary’ or ‘Secondary’ channel refer to the
GNSS output channel.
Correction Source
Bottom-Track XYZ
Which velocity measurement is used to correct the
measured water-velocities.
Depth Source Selection
Automatic
What data is used for measuring the depth.
Navigation source
Primary Channel
If multiple sources of navigation are available you can
select a specific one here. Not necessary if the system
is only used with the standard GNSS.
Use magnetic sensor
No
Optionally use the magnetic compass in the Signature
sensor. This usually does not work on a steel ship.
Use NMEA output
Channel
No
Enable the NMEA compatible output. See section
NMEA Output for details.
Use Secondary Channel
No
Store GNSS data from the Secondary Channel.
Instrument Origins
GNSS Mounting
0m,0m,0m,0 º
Offsets of the GNSS from a reference point on the
vessel. Check chapter 6 for details
Signature Mounting
0m,0m,0m,0 º
Offsets of the Signature from a reference point on the
vessel. Check chapter 6 for details
Processing Settings
Average Interval [s]
1
Measurements are averaged over this interval.
Correlation limit [%]
50
Any measured cell where the correlation is lower than
this limit is discarded.
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5.2 Start the measurement
When every sensor was checked and found to be working, as described in the previous section, the system
can be started by simply clicking the ‘Connect’ button:
When the instruments are connected, click the ‘Start measurement’ button. There will be a pop-up window
where you can set or verify the main measurement settings:
Figure 19 Start measurement pop-up window
When entering new values in the edit boxes they are automatically checked, and if a setting is not
compatible with the connected sensor the edit box will be marked red and the ‘Start’ button will be disabled.
Setting
Default
Description
Environment
Salinity / Sound Velocity
35 / 1500
Click on this field to switch between ‘Salinity’ or
‘Sound-Velocity’
The salinity is 0 for fresh water and typically 35 ppt for
the ocean. This is used for automatic calculation of
sound-velocity.
If Sound Velocity is selected, a fixed speed of sound in
Connected, the button is now
set to ‘Disconnect’
Click this to bring up the pop-up
window
Click to switch between
‘Salinity’ and ‘Sound velocity’
Start the measurement .
Echosounder Settings.
Only available when the
instrument has an
Echosounder license.
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water has to be entered. In general, this is around
1500 m/s in seawater.
Mounting depth [m]
0
The depth below the surface at which the instrument is
mounted.
Velocity Measurement
Blanking distance [m]
0.5
Distance to the start of the first measuring cell.
Cell Size [m]
0.5
Size of each measuring cell. A larger cell size will
improve the accuracy per cell, at the cost of losing
vertical resolution.
The total number of cells that is recorded is limited by
the selected cell size. The total measured distance (Nr
of Cells * Cell size) cannot exceed the maximum
range of the instrument.
Echosounder
Echosounder specific settings. Only available if the
instrument has an echosounder licence. Two
echosounder measurements are available, each can
be enabled or disabled.
Blanking distance [m]
0.1
Distance to the start of the first measuring cell.
Cell Size [m]
0.5
Size of each measuring cell. This basically sets the
vertical resolution of the echosounder.
Echogram
If disabled this echosounder mode is not used.
(echosounder is NOT recorded!). Select a frequency
from the dropdown box to enable the echosounder.
Most Signature sensors only have one frequency
available, which is the base frequency of the sensors
itself (e.g. 1000 kHz for a Signature 1000). On a
Signature 100 with echosounder option mounted it
may be possible to select different frequencies.
Pulse compression
on
Only available for the first echosounder.
Transmit length (ms)
0.1
Length of the transmit pulse in ms.
Note: If you change these values and want to store them for future measurements, open the ‘Configuration
window’ and click ‘Save configuration’
Click ‘Start’ to start the actual measurement. When any of the settings in this window is invalid for this
specific sensor the Start button is not enabled and the measurement cannot be started.
The system will now start recording the measurement data. When it is recording this is indicated by the two
progress bars that are visible when clicking at the bottom of the ‘Settings’ window. Use ‘Next recording’ to
create a new file. This may be useful to start a new file when a specific area or track is started.
Figure 20 Recording and recording status
Click ‘REC’ to start a new
recording
Recording status will bring up
the popup
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5.3 Measuring and Display
5.4 Status
Figure 21 Status panel
Hover the mouse cursor over the ‘Measurement settings’ to show additional details on the current
measurement.
Figure 22 Measurement settings pop-up
Current: Averaged current speed and direction
referenced to earth.
Vessel Velocity Through Water. Speed and
direction of the vessel relative to the water.
Bottom Track: Vessel Speed and Direction
over Ground as measured by the Signature.
Depth: Depth as measured by the central
acoustic beam in the Signature
Global Navigation Satellite System: Vessel
Speed and Direction over Ground as measured
by the GNSS.
Heading: Heading of vessel as measured by
the GNSS
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5.5 Track display
Figure 23 Track display with track details
The track display shows the track as sailed by the vessel, and recorded by the GNSS, in blue dots. The
calculated track from the bottom track data is shown as red dots. Note that the background map may only be
visible if there is a live internet connection since these maps are loaded form either Bing or Google maps.
Clicking the round ‘< ‘ button on the right top of the map opens the map options menu.
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Figure 24 Track display options
When the calculated track starts to drift away from the actual track you can reset it by clicking ‘BT Reset’ or
press <Ctrl>-R on the keyboard. ‘Refresh’ will re-center the map.
If ‘Automatic Center’ is enabled, the map will automatically shift the ship track to the centre if it gets too close
to the edge.
Show heading line: show a straight line that marks the heading according to the GNSS compass.
Show Bottom Track : Show the course as calculated from the bottom-tracking.
Show altimeter: Show the depth at regular intervals.
Allow internet: If a map is not already available on this computer, use the internet connection to collect it.
This could be disabled if the computer is connected to internet over low bandwidth connection.
The last item in the list is a drop-down box where you can select the source of the map. OpenSeaMapHybrid
is usually a good choice, but its servers are sometimes slow and so you might want to switch to Google or
Bing maps.
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5.6 Echograms
Figure 25 Echograms with displaying options
The chart on top shows the magnitude (absolute value) of the current velocity. The lower chart can show
either ‘Direction’, ‘Correlation’ or ‘Amplitude’ for one of the four beams.
The ‘filter’ icon will show either all data up to the detected bottom , or all data for the maximum depth.
Default scaling for the vertical axis is automatic. The program tracks the bottom and adjusts the scaling so
all relevant data is in view. If you want to focus on a specific section or just want to see all, click the ‘Depth’
button. Now adjust the depth scale by clicking and dragging it with the mouse.
5.7 Keyboard Shortcuts
F1 Move between tabs in the Settings window
<Tab> and Arrow Keys Move between settings. Use Spacebar to toggle checkboxes
<Ctrl>-R Reset bottomtrack. Re-Align the bottomtrack with the vessel position on the Map
+ Zoom in on the Map
- Zoom out on the Map
<Ctrl> Arrow Keys Pan the Map
5.8 Error Messages
Occasionally the system may show error messages after starting the Signature Sensor. These messages
are displayed as sent by the instrument and in general have the following structure:
NUM=n, STR=”<Error Message>”, LIM=”<Limits as exceeded>”
The ‘NUM’ is the numeric value of this error, ‘STR’ is the human readable description and ‘LIM’ are the limits
that were exceeded leading to the error. Usually the text will give the user a hint as to where or why the error
occurred.
The most common error is the following:
Remove data below
the bottom.
Zoom to extents
Toggle ‘Drag to Pan’
Zoom
Enable / Disable
manual vertical
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‘NUM=9,STR=”PTP clock not synchronized”,LIM=””
This indicates that there is no PTP (Precision Time Protocol) signal present. This signal should come from
the GNSS, so this either may not be connected yet, or the GNSS has not locked in to any satellites and
therefore has not found the correct time.
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6 Offsets
Before starting the actual measurement, it is important to align all sensors. The configuration contains two
sub-sections for entering the offsets between sensor, GNSS and vessel. All calibration factors can still be
changed in post processing without further consequences.
Figure 26 Signature and GNSS mounting offsets
6.1 Vessel Coordinate system
As shown in the illustration there are three different coordinate systems that apply.
Figure 27 Vessel coordinate system
First there is the ship itself, to which everything should be aligned. The centre axis is the X-Axis, and forward
is positive. The angles are right-hand, so positive angles are clockwise.
SHIP
GNSS
Signature
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Second is the GNSS which should be aligned with the vessel centreline, but could be a few degrees off
And finally, there is the Signature sensor which by default has 45 degrees offset if installed according to the
instructions in ‘Installation’ chapter. It is worth noting that the Signature sensor is essentially mounted
‘upside-down’. The offset as entered in the software is the rotation as related to the vessel, so it is minus 45
degrees in this case.
Figure 28 Signature and GNSS mounting coordinates
To illustrate the GNSS orientation offset it shown here at 10 degrees as an example. This offset should be
as small as possible, and only if it is not possible to get it exactly to 0 correct it in the software.
6.2 Horizontal and vertical offsets
The easiest way to have everything aligned is to mount the Signature and GNSS on a single pole so they
are on the same vertical axis, as shown in the image above. This way there is no need to enter X and Y
offsets.
If, however this is not possible, X Y and Z offsets may have to be entered like in the example below where
the GNSS is mounted on the roof of the vessel. When entering X,Y and Z offsets it is important to start from
Signature mounted in frame,
bottom view.
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NORTEK
deciding what is the actual reference point. If, for example, we take the Signature sensor as a reference we
only have to enter offsets for the GNSS.
Figure 29 Offsets from the GNSS to the Signature
In the example the Y offset from the Signature to the GNSS is -3.45 and the X Offset is +1.43. Since the
Signature is the reference (point 0,0,0) and we are entering the offsets FROM the Signature TO the GNSS.
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6.3 Orientation of the GNSS and Signature
Next align the ‘Heading’ and the GNSS direction. The heading, measured by the GNSS, is the actual, true
north, direction that the antenna is pointing at. The direction as indicated under the ‘Global Navigation
Satellite System’ label is the direction in which the ship moves, relative to earth. When adjusting this it is
important that the vessel is moving in a straight line, preferably straight into or with the local current. If the
current (or strong wind) is coming in from the side, the vessel will drift sideways which will give an incorrect
direction of movement. To adjust the offset, open the ‘Configuration’ and adjust the ‘Heading Offset’. The
correction will be applied immediately after pressing ‘Enter’ or ‘Tab’.
Don’t forget to click ‘Save Configuration’ !
The Bottom track velocity and direction are measured relative to earth by the Signature. The GNSS velocity
and direction should match. In the example shown in the status screen this is not the case. This also shows
up very clearly in the track plot. The blue line shows the track according to the GNSS, the red line according
to the bottom tracking. It’s clear that the bottom track direction is about 45 degrees off, which is due to the
45 degrees offset of the Signature sensor.
These values should match
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NORTEK
To correct for this, open the ‘Configuration’ and adjust the ‘Signature Orientation’, in this case to -45
degrees. The correction will be applied immediately after pressing ‘Enter’ or ‘Tab’.
Don’t forget to click ‘Save Configuration’ !
After changing the offset, the
direction of the bottomtrack line
Click ‘BT Reset’ to align
the bottomtrack line
with the vessel position
When properly aligned, these two
directions should match
(+/- 1 degree)
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7 Output
7.1 NMEA Output
NMEA compatible output is available as UDP messages and may be sent to a user specified IP address and
port. To enable NMEA output, first select ‘Use NMEA output
channel’ in the Configuration window. Now click the ‘NMEA
output settings’ button. Here you can set the specific
parameters for the local IP address where the data should be
sent. The address can be a specific destination like
‘192.168.1.123’, a broadcast address like ‘10.0.0.255’ or it can
be a multicast address as show in the example. In general
addresses in the 239.x.x.x range are known as multicast
addresses and can be received by multiple computers on the
network. Broadcast addresses can be received by computers
on the same network with the same network-mask.
All messages conform to the NMEA-0183 version 3.01 format.
All begin with $ and end with a carriage return and a line feed.
Data fields follow comma (,) delimiters and are variable in
length. Null fields still follow comma (,) delimiters, but contain no
information.
An asterisk (*) delimiter and checksum value follow the last field
of data contained in an NMEA-0183 message. The checksum is
the 8-bit exclusive OR of all characters in the message,
including the commas between fields, but not including the
$ and asterisk delimiters. The hexadecimal result is converted
to two ASCII characters (0–9, A–F). The most significant
character appears first.
In the NMEA options window the required messages can be
selected. Note that if specific data is not available, no message
will be sent.
7.1.1 $SDDBT –Echosounder- Depth Below Transducer
Field
Description
DataFormat
Depth, feet
Depth below transducer in Feet
dd.dd
F
The letter ‘f ‘for feet
Depth, meters
Depth below transducer in Meters
dd.dd
M
The letter ‘M ‘for Meter
Depth, fathom
Depth below transducer in Fathom
dd.dd
F
The letter ‘F’ for Fathom
Example:
$SDDBT,32.81,f,10.00,M,5.47,F*39
Figure 30 Enabling NMEA output
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7.1.2 $SDGGA - Global Positioning System Fix Data
Field
Description
DataFormat
Time
HHmmss.ss
Latitude
Geographical Latitude
dddd.dd
N or S
The letter ‘N’ or ‘S’ for North or South
Longitude
Geographical Longitude
ddddd.dd
E or W
The letter ‘E’ or ‘W’ for East or West
Quality
GPS Quality Indicator
N
Nr Of Satellites
Number of satellites in view, 00 - 12
NN
HDOP
Horizontal Dilution of precision (meters)
dd.d
Altitude
Antenna Altitude above/below mean-sea-level (geoid) (in
meters)
dd.dd
M
Units of antenna altitude, Meters
Separation
Geoidal separation, the difference between the WGS-84 earth
ellipsoid and mean-sea-level (geoid), "-" means mean-sea-level
below ellipsoid
dd.dd
M
Units of separation, Meters
ddd.ddd
Differential Age
Age of differential GPS data, time in seconds since last SC104
type 1 or 9 update, null field when DGPS is not used
N
Reference Station
Differential reference station ID, 0000-1023
NNNN
Example:
$SDGGA,121816.244,5134.6213945,N,00405.4297275,E,0,00,0.0,-10.0,M,0.0,M,,*7A
7.1.3 $SDVTG - Track made good and Ground speed
Field
Description
DataFormat
Track Degrees
Heading in degrees North
ddd.dd
T
The letter ‘T’ for True North
Track Degrees
Heading, magnetic north
ddd.dd
M
The letter ‘M’ for Magnetic North
Speed Knots
Speed over ground in Knots
dd.dd
N
The letter ‘N’ for knots
Speed km/h
Speed over ground in km/h
dd.dd
Example:
$SDVTG,0.00,T,,M,1.85,N,3.60,K*59
The following messages are a subset of the messages as used by the Nortek DVL (Doppler Velocity Log),
but the ‘Tagged NMEA’ versions are not supported (e.g. $PNORS2,DATE=083013,TIME=132455,EC=0, SC-
34000034…)
7.1.4 $PNORI1 – General Information
Field
Description
DataFormat
Instrument Type
N Head Id
Serial number of instrument
N
Number of Beams
N Number of Cells
Number of valid cells
N
Blanking Distance
[m]
dd.dd
Cell Size
[m]
dd.dd
Coordinate System
Always E(ast) N(orth) U(p) for
Signature VM
ENU
Example:
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$PNORI1,4,123456,3,30,1.00,5.00,ENU*5B
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7.1.5 $PNORS1 – Sensor Data
Field
Description
DataFormat
Date
MMDDYY
Time
Hhmmss.ss
Error Code
See Signature manual for details
N
Status Code
See Signature manual for details
N
Battery Voltage
[V]
dd.d
Sound Speed
[m/s]
dddd.d
Heading
True Heading [deg]
ddd.d
Heading Std Dev.
[deg] (Not Used, always 0)
dd.dd
Pitch
[deg]
dd.d
Pitch Std Dev.
Standard Deviation [deg]
dd.dd
Roll
[deg]
dd.d
Roll Std Dev.
Standard Deviation [deg]
dd.dd
Pressure
[dBar]
ddd.ddd
Pressure Std. Dev.
Standard Deviation [dBar]
dd.dd
Temperature
[deg C]
dd.dd
Example (DF101):
$PNORS1,083013,132455,0,34000034,23.9,1500.0,123.4,0.02,45.6,0.02,23.4,0.02,123.456,0.02,24.56*39
7.1.6 $PNORCV – Velocity data per Cell
Field
Description
DataFormat
Date
Date and Time in UTC
MMDDYY
Time
0-24H, 0.01 second resolution
Hhmmss.ss
Cell Number
#
Dd
Cell Position
Distance from sensor to centre
of the cell[m]
dd.dd
Velocity East
[m/s]
dd.ddd
Velocity North
[m/s]
dd.ddd
Velocity Up
[m/s]
dd.ddd
Velocity Up2
[m/s]
dd.ddd
Speed
[m/s]
dd.ddd
Direction
[degrees]
ddd.dd
Amplitude Units
D=dB
D
Amplitude Beam 1
[dB]
ddd.d
Amplitude Beam 2
[dB]
ddd.d
Amplitude Beam 3
[dB]
ddd.d
Amplitude Beam 4
[dB]
ddd.d
Correlation Beam 1
[%]
dd
Correlation Beam 2
[%]
dd
Correlation Beam 3
[%]
dd
Correlation Beam 4
[%]
dd
Example:
$PNORCV,201419,112049.21,59,29.7,-2.464,-3.178,0.55,0.396,4.022,217.788,D,33,33.5,33,32.5,12,32,34,21*78
7.1.7 $PNORC1 – Velocity data per Cell
Field
Description
DataFormat
Date
MMDDYY
Time
Hhmmss
Cell Number
#
Dd
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Cell Position
Distance from sensor to centre
of the cell[m]
dd.dd
Velocity East
[m/s]
dd.ddd
Velocity North
[m/s]
dd.ddd
Velocity Up
[m/s]
dd.ddd
Amplitude Beam 1
[dB]
ddd.d
Amplitude Beam 2
[dB]
ddd.d
Amplitude Beam 3
[dB]
ddd.d
Amplitude Beam 4
[dB]
ddd.d
Correlation Beam 1
[%]
dd
Correlation Beam 2
[%]
dd
Correlation Beam 3
[%]
dd
Correlation Beam 4
[%]
dd
Example (DF101, 4 beams)
$PNORC1,083013,132455,3,11.0,0.332,0.332,0.332,0.332,78,78.9,78.9,78.9,78,76,72,76*46
7.1.8 $PNORBT4 – Speed over ground and depth
Field
Description
DataFormat
DT1
Time from trigger to bottom
echo (NOT USED)
d.ddd
DT2
NOT USED
d.ddd
Speed Over Ground
[m/s]
d.ddd
Direction
[degrees true North]]
d.d
Figure Of Merit
#
dd.ddddd
Distance to Bottom
[m]
dd.d
Example:
$PNORBT4,0,0,1.234,23.4,12.34567,12.3*09
7.1.9 $VDVDR – Current Speed and Direction
The VDR sentence contains the corrected current speed and direction. These are the same values as shown as current
sticks in the Track plot, i.e. averaged over time and profile.
Field
Description
DataFormat
Direction
[degrees true North]
ddd.d
“T”
Marker for True North
T
Direction Magnetic
<empty>
“M”
Marker for Magnetic heading
M
Speed
Current Speed in knots
dd.dd
“N”
Marker for Knots
N
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NORTEK
8 Installation
8.1 Instrument orientation
When mounting the Signature sensor to the vessel it is important to note the orientation. As shown in the
figure, the ‘X’ is not pointing straight forward, but 45 degrees off the centre line. If mounted like this, the
heading offset as used by the software should be set to 45 degrees (See section 6 (Offsets) for details on
how enter the orientation)
Figure 31 Signature orientation relative to the vessel
8.2 Mounting Considerations
8.2.1 Bubbles
Try to avoid mounting the Signature sensor in areas where bubbles from the propeller or thrusters will pass
over the Signature sensor head. The system can tolerate some bubbles in front of the acoustic transducers
but when the bubble-cloud gets too dense, the acoustic energy will be blocked and the profiling range will be
greatly reduced. Also, bubbles on the sensor head will change the speed of sound and potentially lead to
erroneous results in the velocity measurements.
In order to avoid interference from bubbles, the best solution is to find an area under the hull where there
are fewer bubbles. It this is difficult, it can be a good idea to mount a V-shaped structure in front of the
Signature sensor that will deflect the bubbles. Another possibility, often used with commercial echo
sounders, is to mount the Signature sensor on a piston rod that can be moved as much as 0.5-1m below the
hull so the sensor head is located below the bubble layer.
8.2.2 Grounding
Fore
Aft
Bottom View
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Grounding Point.
This should always be submerged !
When mounting the sensor in a ship’s hull or on another platform, make sure the grounding point always
touches the water.
8.2.3 Ship movements
Try to avoid mounting the Signature sensor too close to the bow or to the stern. Instead, the best areas are
toward the middle of the ship. There are two reasons to pick an area toward the middle. First, the vertical
motion due to pitch and roll is minimal toward the middle. Second, the ship-induced flow field has stronger
asymmetries toward the bow and stern. These asymmetries will reduce the accuracy of the velocity data
close to the hull and are best kept to a minimum. Ship induced motion is usually a bigger problem the larger
the ship, the relative water depth is smaller, and the ship is more bulky (less "classic" hull structure). It is
usually not a significant problem on small vessels or for Signature Sensors mounted over the side.
The tilt angle of the installation should be as small as possible because a level sensor head makes it easier
to interpret and analyse the velocity data. However, a few degrees of tilt does not make a great difference in
the accuracy of the horizontal velocity data
8.2.4 Ship generated flow fields
All ships generate their own flow field. The magnitude of this field is a function of the ship size, shape, ship
speed, and the water depth. It is weaker away from the hull than it is close to the hull and it will be weaker
on the side of the ship than it is directly below the hull. The magnitude of the flow field can be analysed by
looking for persistent vertical gradients in the velocity data.
a) The flow field is strongest close to the hull and will usually "pull the water along with the ship". As a result,
the sign of the velocity gradient will remain constant and it will not change direction as the ship moves in the
opposite direction. If the gradient remains constant, regardless of the direction of the ship motion, it is not a
part of true current regime, but an artefact of the ship induced flow field.
b) When the Signature sensor is mounted close to the bow or to the stern, it will show a net vertical velocity
close to the hull. If the vertical velocity has a strong gradient (i.e. it is not constant with the water depth), it is
usually a result of the motion.
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NORTEK
8.2.5 Over the Side Mounting
Movable mounts are used for short term surveys or when the Signature sensor will be moved from ship to
ship. Most of these mounting arrangements are designed so the Signature sensor will be mounted over the
side. It is important that the mount is rigid so that the orientation of the Signature sensor does not change
over the course of the survey.
Note that the relative orientation of the Signature sensor as referenced to the GNSS coordinate system
should remain unchanged over the survey. Mounting systems that uses a separate, towed catamaran or
other towed body are not suitable unless the GNSS antenna is also mounted on the towed body.
The instrument may be supplied with an over the side mounting frame. This stainless-steel frame is basically
a container for the Signature instrument that protects it against damage from impact and to ease the waterflow around it. Using the drop-shaped cover will also significantly reduce the drag on the instrument when it
moves through the water.
For maximum flexibility, the top of the container has 8 slots that fit M12 bolts. It is up to the user to provide a
mounting structure with a mating flange. The example shows a standard flange, model EN 1092-1.
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1. Mount the bolts on top of the cylinder and align them with the holes in the flange (A)
2. Route the cable and connect it to the instrument
3. Mount the instrument, using the optional internal clamp (B) and the four bolts (C).
4. Attach to the flange
5. Finally mount the drop-shaped cover(D), line-up the rectangular bolts with the slots in the cover.
A
D C B
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NORTEK
GNSS Mounting
Ideally the GNSS antenna should be mounted as close to the Signature as possible, or at least in the same
vertical plane. This is not always possible and there may be several other mounting considerations like the
clear view of the sky or nearby radar. It is not a huge problem if it isn’t completely aligned but the closer the
better.
The GNSS antenna comes with a stainless-steel Mast/Rail bracket that can be clamped to a horizontal or
vertical pole as shown in the figure below.
GNSS Compass ideal mounting
location for the vessel.
Optimal location: right
above the instrument.
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To attach the antenna to the mounting pole, first put the nut and the plastic ring on the thread, then screw on
the antenna. Point the antenna so it is in line with the ship’s main axis and fix it in position using the nut.
Figure 32 Mechanical drawing of GNSS Compass
Figure 33 GNSS Ethernet Cable
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NORTEK
9 Maintenance
9.1 Signature Sensor
We recommend a regularly scheduled procedure which will act as a preventative measure to ensure your
instrument continues functioning as intended. The following sections can be used as a maintenance
guideline for the components that may be exposed to wear and tear.
• When cleaning the external surfaces use a mild detergent and be extra careful with the
transducers.
• Check the pressure sensor and remove any dirt from the holes in the lid. Be careful when
opening the pressure sensor cap as it is easy to dent and damage the sensor.
• Be careful when cleaning and lubricating the connectors.
• When opening the instrument, great care should be taken to keep the sealing surfaces clean and
protected from mechanical damage. Always keep water out of the open housing. The grounding
point should always be free from biofouling.
9.2 Biofouling
Current profilers used in long term monitoring projects will become covered with biological material.
Eventually, the growth can become strong enough that the transducers are blocked, and the profiling range
is reduced. To know when to maintain the instrument it is best to monitor the long-term variation in the
amplitude data. This parameter varies with short time scales (depending on suspended sediment
concentration, zoo plankton, bubbles, etc.), but biological growth (especially barnacles) adds a long-term
downward trend that can be monitored. The profiling range gradually goes down as the growth on the
sensor increases. At some point, the signal strength will be too low to get the desired profiling range.
Through experience you will gain knowledge about how long it takes before the transducers are covered
and this information can later be used to set regular maintenance intervals where the transducers are
cleaned.
When the instrument leaves the factory, the surfaces are quite smooth, and it will take some time before any
growth starts. After the first cleaning, the surface is rougher, and it becomes easier for new material to grow.
Typical maintenance intervals are 6-12 month, but the growth rates vary a lot with the geographical location,
water temperature, season, and deployment depth. In general, heavy growth is seen in hot and shallow
areas. Cold- and deep-water areas see very little growth so maintenance can be less frequent.
To clean the transducer we recommend not to use strong organic solvents such as acetone. Barnacles have
to be removed mechanically, but we strongly advise against using sharp objects capable of harming the
surface.
9.2.1 Antifouling Paint and patches
The important thing regarding painting transducers is that the paint is not too thick, otherwise the signal
strength will decrease. You can probably use most anti-fouling paints as long as it is not too (chemically)
aggressive and contains no solids (metal flakes, etc) that could interfere with acoustic beams. Anodes and
pressure ports should not be painted. For permanent hull mountings on vessels with a low maintenance
interval, Nortek advices to use antifouling patches. These consumables can be purchased via the
Nortekgroup web shop. The patches double the standard cleaning interval and a diver can quickly clean the
patches from marine growth.
9.3 Instrument Care
All Nortek instruments are intended for use in water. Other fluids may have an adverse effect on the plastic
materials used. For prolonged storage at elevated temperatures close to the specified limit, or when
temperature variation is uncertain, it is recommended that the screws securing the end cap be loosened in
order to minimize the risk of any deformation due to temperature/stress over time.
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If the instrument has been subjected to environmental conditions outside the specified design limits (refer to
the instrument brochure for specifications) mechanical tolerances may be affected.
9.4 Connector Care
It is extremely important to keep connectors clean and well lubricated. Before plugging in connectors we
recommend to always blast the pins with compressed air, inspect them for cleanliness and then protect the
cable connector by applying a thin layer of silicone grease.
Before deployment:
• Disconnect.
• Flush the connector set with fresh water or compressed air, remove dirt. Remember to
also check the female connector.
• Check that both connectors are dry. If not, let them air-dry.
• Inspect for damage, corrosion and cuts.
• Apply a thin film of Silicone grease.
• Mate the connector halves and check if they are properly mated.
After deployment and before storage:
• Flush the connector set with fresh water or compressed air, remove dirt.
• Check that both connectors are dry. If not, let them air-dry.
• Inspect for damage, corrosion and cuts.
• Mate with dummy plug if available.
9.5 Cable Care
• Do not pull on the cable to disconnect connectors.
• Avoid sharp bends at the cable entry to the connector.
• Ensure that the cable is fixed to the mounting fixture to avoid mechanical stress to the
connection.
• Elastomers can be seriously degraded if exposed to direct sunlight or high ozone levels
for extended periods.
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NORTEK
10 Troubleshooting
This section contains information on where to start looking if an instrument does not behave as intended. If
you encounter a problem, you should:
1. Get a good overview of the problem; make notes during the troubleshooting process
2. Work in a systematic way and do not neglect the obvious. Start by looking at simple causes, such
as power not connected, bad connections, etc.
3. If the setup uses custom cables, power supply, etc. first assemble and test the instrument using
the cable and battery (if applicable) that originally came with the instrument. You can always
return to the standard setup, which is the easiest way to get the system to work, to confirm that
the problems are not caused by a faulty instrument.
4. If your instrument behaves strangely try updating both your software and firmware to the latest
versions. There may be incompatibility between an older version of firmware and newer version
of software, and vice versa. The latest versions of firmware and software can be downloaded
from our support page
To help us give good support, please
1. Be specific about the error - a screenshot is often helpful
2. Include a raw sample file or a collected data set showing the error
3. Include information about firmware and software version used
4. Include serial number (Head ID, Hardware ID or order number)
10.1 Remote Support through TeamViewer
In general, every Signature VM computer comes with the TeamViewer software. This allows the user to give
a Nortek support engineer access to the computer so he or she can check what might be wrong with your
software or configuration. Make sure you have a working internet connection, and when requested by the
Nortek engineer, click the TeamViewer icon to start a session.
Note that every time a TeamViewer session is started, a notification will be sent to Nortek.
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When the program has started successfully, and the ‘Ready to connect’ message is visible no further action
is necessary. The Nortek engineer can now connect to your computer and try to solve your problem.
10.2 Communication
The blue LED indicator light on the instrument is not lit
• Is the instrument in Command mode?
• Does the LED blink (short) when applying power?
10.2.1 Cable
Cables are often exposed to heavy use and the power connector might break. Using a multimeter to ping
through each pin may reveal a breakage.
10.3 Power
10.3.1 Interface does not switch on
First check the status of the fuses on the rear:
Inspect the fuses, or measure them using a multimeter. Replace if necessary. Both fuses are 5x20 mm glass
fuses, 1.6A, Slow Blow.
10.3.2 Power to the Signature sensor
The Signature is powered from the 48 V power supply in the interface box. The exact same power line is
used for the ‘Power LED’ on the front panel, so if this is LED is lit, there is power. Just above the power
connector on the rear is a fuse, which is a 3.15 A, slow blow.
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Figure 34 Power connector and Fuse
11 Computer configuration
The data acquisition computer is configured to work as a standalone unit. No connection to an external
network or the internet is required.
Two Ethernet ports are available. One is named ‘Ethernet’ and is a general-purpose port that may be used
to connect to internet.
The port named ‘SurveyVM Interface’ is set to a fixed IP address: 192.168.100.1. This port is connected to
an Ethernet switch inside the interface box, and the sensors are connected to this switch.
An OpenDHCP server is running on the computer as a service. This is configured to use only the ‘SurveyVM
Interface’ port so DHCP will only work on this port, and addresses used will always be in the range 192-
168.100.1 to 192-168.100.254
OpenDHCP was added to the Windows firewall as an allowed application.
Both the Signature Sensor and the GNSS are set to ‘DHCP’ so they will get an address from the computer
when connected to the ‘SurveyVM Interface’.
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Remote Desktop is enabled, and this is explicitly bound to the 192.168.100.1 address, so it will only work if a
computer is connected directly (or through a switch) to the ‘SurveyVM Interface’ port. Remote desktop is not
possible over the ‘Ethernet’ port.
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12 GNSS
The Advanced Navigation GNSS Compass can be monitored and configured through its internal webinterface. Some settings require the user to enter a username and password. The default settings are:
Username : admin
Password : password
The instrument comes in two variants: a standard (LC) and a High Accuracy (HA) version. Both offer the
same accuracy in heading, roll and pitch, but the HA version has a more accurate horizontal and vertical
position.
Figure 35 Identifying the version of the GNSS on the serial number sticker
12.1 Filter setting
Standard filter setting on the GNSS is ‘Small Boat’, which is shown to work fine with most survey vessels.
Should the system be used on larger vessels it could be set to ‘Ship’. Note that changing the filter settings
will not alter the response or lag of the measurements, it just helps the instrument to find a fix by giving it
some information on the expected movements.
12.2 Increasing the accuracy using RTK (NTRIP)
The Advanced Navigation GNSS can receive external correction signals over the Ethernet link using a
protocol named ‘NTRIP’ (Networked Transport of RTCM via Internet Protocol). The GNSS has a built-in
NTRIP client that can be configured through the menu.
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NTRIP data is supplied by several different providers. Usually it’s a local, commercial service of a company
that maintains the local network of reference stations.
The use of the NTRIP client requires that the system is connected to the internet. To test if it is working, use
the server at ‘www.rtk2go.com’, port 2101 as shown in the example above. This is a cloud service that
provides free transfer of data from any base station. Most of them are just private stations which will often be
offline, but the ‘Get Mountpoints’ function will work and fill the drop-down list with available stations.
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13 Glossary
Accuracy
A value giving the degree of closeness of a velocity measurement to the
actual velocity. Refer to the data sheet for specific minimum accuracy.
AD2CP
Nortek's broadband signal processing platform.
AHRS
Attitude and Heading Reference System. Provide attitude information and
replace the traditional tilt and magnetometer. AHRS is especially useful in
dynamic environments. Note that this feature also requires additional
hardware.
Altimeter
Measures the distance to the surface
Amplitude
See signal strength
ASCII output
Data is displayed in ASCII format (plain text).
Bandwidth
Wider signal bandwidth is used to get more information and improve the
velocity precision. Reduced bandwidth is used in long range mode (only
relevant when current profiling) to increase range. This bandwidth reduction
makes the measurements less precise.
Beam
Coordinates
In Beam coordinates, a positive velocity is directed in the same direction as
the beam points. Beam 1 is marked with an “X” on the head.
Blanking
Specifies the distance from instrument head to the start of the measurement
cell where no measurements take place, to give the transducers time to settle
before the echo returns to the receiver. The size of the blanking area is user
selectable in the software using the Start of profile parameter.
Break
A break command is used to change between the various operational modes
of the instrument and to interrupt the instrument regardless of which mode it is
in. When break is received in command mode, you can see that the LED is
switched off for a short time.
Broadband
In this context it means using a more complex transmit pulse to improve the
measurement accuracy in each ping.
Cell
One measurement cell represents the average of the return signal for a given
period. The cell size and transmit pulse are of equal size. The cell is shaped
like a triangle due to convolution; this is indicative of the weighting of the
measurement.
Coarse Profile
Instrument setup that prioritizes achieving the maximum range at the expense
of reduced resolution.
Command mode
An instrument in command mode is powered up and ready to accept your
instructions. If no commands are received for about five minutes, it
automatically goes into Power Down Mode, unless Ethernet power is
connected. LED is lit constantly when in command mode.
Compass
calibration
Each compass system has been calibrated at the factory to quantify the
characteristic response of the individual components and of the system as a
whole. When it leaves the factory, each system can measure its tilt and the
direction of its magnetic field vector accurately. However, users may disturb
the magnetic field near the instrument when they deploy. Adding a battery
pack and mounting the instrument with deployment hardware adds magnetic
materials that change the earth's field at the instrument. The compass
calibration procedure quantifies this magnetic hard iron disturbance, and the
instrument's compass algorithm then corrects for it to obtain accurate
heading.
Correlation
(nominal)
Nominal correlation is a function of cell size and velocity range. Nortek
recommends using 50% of the max correlation as a cut-off value, beyond this
point the validity of your data is questionable.
ENU
Coordinates
Polar magnetic coordinates; East, North and Up. A positive east velocity goes
toward east. This is a right-handed orthogonal system.
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Fine Profile
Instrument setup that prioritize the highest possible resolution at the expense
of the maximum range achievable.
Firmware
Internal software of the instrument, as opposed to the instrument software
running on a PC. New firmware is posted on the Nortek site. You will need to
register to get access, but access is otherwise free of charge.
Ice Draft (keel)
Measures thickness of ice. Ice draft = Water depth - Distance to Ice
Ice Drift
With the correct firmware and license, measures velocity and direction of ice
drift.
Internal sampling rate
Rate of sampling for internal sensors. Refer to the specific instrument
brochure for details.
LED
Light Emitting Diode, visible from the outside of the instrument. The LED can
be set to blink for every sample (On), blink for the first 24 hours of deployment
(On for 24h), or never (Off).
License
Different capabilities of the instrument are protected under licenses which can
be purchased. Contact your sales representative for more information.
Register purchased licenses while connected to your instrument under
Instrument > Licenses. Licenses that are ordered with the instrument are
already registered.
You will not need a license when updating the firmware version.
NMEA
Standard data format defined by the National Marine Electronics Association
Noise floor
The amplitude of the internal noise of the instrument. This will limit the
minimum detectable signal that can be received.
Ping
Same as a single transmit pulse.
Precision
The value given is a theoretical estimate of the precision of the velocity
measurements based on how the instrument is set up. The nominal value is
given for the horizontal components in a default instrument acoustic beam
configuration. In order to improve the precision the user may consider one of
the following options: (1) larger cell sizes, (2) longer average interval (3)
reduced velocity range, or (4) increased measurement load
Sampling rate
Specifies the rate at which data is output
SDU Coordinates
Speed - Direction - Up.
Sidelobe
The acoustic beams focus most of the energy in the center of the beams, but
a small amount leaks out in other directions. Transducer sidelobes are rays of
acoustic energy that go in directions other than the main lobe. Because sound
reflects stronger from the water surface than it does from the water, the small
signals that travel straight to the surface can produce sufficient echo to
contaminate the signal from the water.
Signal strength
Strength of return signal, presented in dB.
Sleep mode
The instrument is not actively collecting data
SNR
SNR is the Signal-to-Noise ratio and is a data quality indicator
XYZ Coordinates
Cartesian coordinate system. A positive velocity in the X-direction goes in the
direction of the X-axis arrow. The X-axis points in the same direction as beam
1. Use the right-hand-rule to remember the notation conventions for vectors.
Use the first (index) finger to point in the direction of positive X-axis and the
second
(middle) finger to point in the direction of positive Y. The positive Z-axis will
then be in the direction that the thumb points.
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14 Connector Pin Configurations
6-pin connector, Stand alone, Ethernet (N2550-003, N2550-008)
Connector on the
instrument side
Pin
number
Function
Wire
color
Joint
Wire color
Pin
number
Connector on the
computer side
MCIL6M with
MCDLS-F (red)
Male face view:
1
Gnd
Black
Black
Jacket
Center
2-pin jack plug
2
Pwr+
Red
White
3
Rx-
White
Green
6
RJ 45 insulation
connector
4
Rx+
Blue
Green/White
3
5
Tx-
White
Orange
2
6
Tx+
Orange
Orange/White
1
8-pin connector, Serial communication, RS232 and RS422 (N2550-001)
Connector on the
instrument side
Pin
number
Function
Wire
color
Joint
Wire color
Pin
number
Connector on the
computer side
MCIL8M with
MCDLS-F (red)
Male face view
1
Gnd
Black
Black
Jacket
Center
2-pin jack plug
2
Pwr+
Red
White
3
RS232
Tx /
RS422
Tx-
White
Red
2
9-pin DSUB
Female face view
4
RS422
Tx+
Blue
White
8
5
RS232 Rx
/ RS422
Rx+
White
Orange
3
6
RS422
Rx-
Orange
Purple
7
7
NC
White
5*) 8 Shield
Green
*) GND on pin 1 on instrument side, pin 5 on DSUB and on Jack Plug (jacket)
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