Geolux LX-80-15 User manual

Copyright ©2022 Geolux d.o.o. All rights reserved.
LX-80-15 10 Hz
Oceanographic Radar Sensor
User Manual
v2.4.1

Starting Point
Thank you for purchasing the Geolux LX-80-15 10 Hz non-contact oceanographic radar sensor!
We have put together the experience of our engineers, the domain knowledge of our customers,
the enthusiasm of our team, and the manufacturing excellence to deliver this product to you.
You may freely rely on our eld-proven radar technology. The use of top-quality components and
advanced signal processing algorithms ensures that the Geolux oceanographic radar sensor can
be used in various applications and environments.
We have created this User manual in order to assist you with setting up and using the Geolux
instrument.
Should there be any questions left unanswered, please feel free to contact us directly:
Geolux d.o.o.
Ljudevita Gaja 62
10430 Samobor
Croatia
E-mail: [email protected]
Web: www.geolux.hr

Contents
1. Introduction 1
2. Electrical Characteristics 2
3. Connector Pin-Out 3
3.1. Serial RS-232 Interface 4
3.2. Serial RS-485 Interface 4
3.3. CAN Communication Interface (Optional) 5
3.4. Analog 4 – 20 mA Output 5
3.5. SDI-12 Interface 6
4. Installing the Oceanographic Radar Sensor 7
4.1. Measurement Through Materials (Containers) 9
4.2. Rain and Wind 9
4.3. Interference and Multiple Radars 9
4.4. Fogging and Evaporation 10
4.5. Reections 10
4.6. Relative Measurement 10
4.7. Units 11
4.8. Radar Calibration 11
5. Wave and Tide Measurement 12
5.1. Signicant Wave Height 12
5.1.1. Signicant Wave Height as an Average of 1/3 of Highest Waves - H1/3 12
5.1.2. Signicant Wave Height Calculated from Standard Deviation - HS 12
5.1.3. Signicant Wave Height Calculated from Spectral Moment - HS_M0 12
5.2. Wave Periods 13
5.2.1. Zero Up-Crossing Period Calculated from Time-Domain Data - TZUC 13
5.2.2. Zero Up-Crossing Period calculated from the Power Spectrum - TZUC_SPEC 13
5.2.3. Crest Period Calculated from Time-Domain Data - TCREST 13
5.2.4. Crest Period Calculated from the Power Spectrum - TCREST_SPEC 13
5.2.5. Peak Wave Period - TPEAK 14
5.3. Statistical Level Measurements 14
5.3.1. Minimum Water Level - LMIN 14
5.3.2. Maximum Water Level - LMAX 14
5.3.3. Mean (Average) Water Level - LMEAN 14
5.3.4. Median Water Level - LMED 14

6. Radar Settings 15
7. Data Interface 23
7.1. Serial RS-232 Interface 23
7.2. Serial RS-485 Interface 23
8. Data Protocols 24
8.1. NMEA Protocol (RS-232) 24
8.2. Servicing Protocol (RS-232) 26
8.3. Modbus Protocol (RS-485) 33
8.4. SDI-12 Protocol 40
9. Geolux Instrument Congurator 46
10. Troubleshooting 50
11. Appendix A – Mechanical Assembly 57

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LX-80-15 10 Hz Oceanographic Radar Sensor
1
Introduction
Geolux LX-80-15 10 Hz oceanographic radar sensor uses radar technology to provide precise
contactless measurement of water level. Contactless radar technology enables quick and simple
sensor installation above the water surface and requires minimum maintenance. This functionality
is achieved by transmitting a frequency-modulated electromagnetic (radio) wave in 80 GHz
frequency range (W band), and measuring the frequency shift of the electromagnetic wave
reected from the water surface.
Measured distance from the sensor to the water surface is proportional to the frequency difference
between the transmitted and received signal. The radar periodically transmits a linear chirp
ranging in frequency from 77 GHz to 81 GHz. As the distance between the radar and water
increases, so does the difference between the transmitted and received frequency, enabling the
level meter to precisely determine the distance between the sensor and the water. The radio signal
modulation and detection algorithms used in the sensor allow very precise measurements that are
not dependent on air temperature, humidity, or other parameters of the environment.
The oceanographic radar sensor is able to detect objects at distances ranging from 0.2 m to 15 m
and reports 10 level measurements per second (10 Hz) for advanced wave analysis.

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Electrical Characteristics
The electrical characteristics of the Geolux LX-80-15 10 Hz oceanographic radar sensor are given
in Table 1.
Table 1. Electrical Characteristics
Parameter MIN TYP MAX Unit
Communication interface:
RS-232 interface speed
RS-485 interface speed
9600
9600
115200
115200
bps
bps
Radar Sensor
Frequency
Beam-width (3dB) – Azimuth
Beam-width (3dB) – Elevation
77.000
5 (±2.5)
5 (±2.5)
81.000 GHz
°
°
Power supply voltage 9.0 12.0 27.0 V
Power
Operational
Standby mode
Sleep mode
360
150
30
600 mW
mW
mW
Operational temperature range -40 +85 °C
Measurement range 0.2 15 m
Accuracy 2 mm
Resolution 0.5 mm
Ingress Protection Rating IP68
Mechanical ф65 x H78 mm

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Connector Pin-Out
The oceanographic radar sensor uses robust IP68 circular M12 connector with 12 positions and a
mating cable, both delivered standardly with the instrument. The connector and cable details are
shown in Picture 1 while Table 2 gives a detailed description of each pin.
Picture 1. Level Meter Connectors
Table 2. Connector and Cable Pin-out
Pin No. Wire Color Pin Name Pin Description
1 White GND This pin should be connected to the ground (neg-
ative) pole of the power supply.
2 Brown +Vin This is the pin with the instrument’s power supply.
The level meter power supply voltage must be
between 9 VDC to 27 VDC, and the power supply
must be able to provide at least 0.65 W.
3 Green RS232 – TxD RS-232 data transmit signal.
4 Yellow RS232 – RxD RS-232 data receive signal.
5Grey GND Signal ground.
6 Pink CAN – H CAN2.0B high signal. (optional)
7 Blue CAN – L CAN2.0B low signal. (optional)
8 Red V+ Output power supply (+Vin) for supply of exter-
nal optional equipment and for use with analog
4 – 20 mA output.
9 Orange RS485 – D- RS-485 data transmitter/receiver low signal.
10 Dark Red RS485 – D+ RS-485 data transmitter/receiver high signal.
11 Black SDI-12 SDI-12 communication interface.
12 Purple 4 – 20 mA Output Analog 4 – 20 mA output.

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LX-80-15 10 Hz Oceanographic Radar Sensor
Picture 2. Serial RS232 DB-9 Cable
3.1. Serial RS-232 Interface
Serial RS-232 interface is implemented as standard PC full-duplex serial interface with voltage
levels adequate for direct connection to PC computers or other embedded devices used for serial
RS-232 communication.
When the RS-232 interface is connected to a standard DB-9 PC connector, TxD line (green wire)
is connected to pin 2 and RxD (yellow wire) is connected to pin 3. In order for the serial interface
to operate properly, an additional connection of signal GND (grey wire) is needed on pin 5 of the
DB-9 connector. Optionally, Geolux can supply a cable with DB-9 connector connected to the
cable. This requirement must be specied when placing an order.
Several communication protocols are available. Additional custom protocols can be implemented
on request. Detailed description of communication protocols is given in chapter 8 of this user
manual.
3.2. Serial RS-485 Interface
Serial RS-485 interface is implemented as standard industrial half-duplex communication
interface. The communication interface is internally short-circuited, and overvoltage protected.
Depending on the receiving device, the interface can be used with only two wires (D+ dark red
wire & D- orange wire) while in some cases the ground connection (signal GND grey wire) is also
required. For more details please consult receiver specication.
The most common communication protocol used with RS-485 interface is Modbus-RTU, but other
protocols are also available on request. Detailed description of communication protocols is given in
chapter 8 of this user manual.

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LX-80-15 10 Hz Oceanographic Radar Sensor
3.3. CAN Communication Interface (Optional)
CAN communication interface is an optional communication interface that can be used for
special applications. This interface is a higher speed interface (up to 1 Mbps) than other serial
communication interfaces, thus enabling additional data transfer which would otherwise not be
possible with RS-232 and RS-485 interfaces.
CAN interface is disabled in the default sensor version - for additional features using CAN
interface please contact technical support.
3.4. Analog 4 – 20 mA Output
Analog current 4 – 20 mA output is provided for easier compatibility with older logging and control
systems. Output is implemented as current sink architecture with common ground. Maximal
voltage applied to the sink can go up to 30 VDC, providing greater exibility in connection of the
sensor to PLCs, loggers, or data concentrators.
Signal range and function for 4 – 20 mA analog output can be congured in the setup application
so the sensor will be able to signal best suitable value range with available current range. Current
step in the sensor is 0.3 µA, which limits the resolution, so care must be taken while setting the
minimal value to be represented by 4 mA and the maximal value to be represented by 20 mA, so
the resolution is sufcient for the system requirements.
Measurement of the current by the client device (logger, PLC, modem etc.) must be implemented as
the high side current measurement as shown in Picture 4. If a sensing resistor is used, resistance
should be selected from the range of 10 Ω up to 500 Ω, with a recommended value of 100 Ω for
the sensing resistor.
Picture 3. Analog 4 – 20 mA Output Internal Architecture

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Picture 4. High Side Current Measurement for the 4 – 20 mA Analog Output
3.5. SDI-12 Interface
SDI-12 interface is widely used to connect hydrological equipment to dataloggers. SDI-12 uses a single
communication line, and very slow speed communication to enable the use of very long communication
cables.
For hydrological applications, SDI-12 communication interface is a valid option and the instrument is
natively able to communicate directly with SDI-12 master devices (dataloggers etc.).