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Copyright ©2022 Geolux d.o.o. All rights reserved.

LX-80-15 10 Hz

Oceanographic Radar Sensor

User Manual

v2.4.1

Summary of Contents for LX-80-15

Page 1: ...Copyright 2022 Geolux d o o All rights reserved LX 80 15 10 Hz Oceanographic Radar Sensor User Manual v2 4 1 ...

Page 2: ...ely on our field 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 u...

Page 3: ...nt Wave Height 12 5 1 1 Significant Wave Height as an Average of 1 3 of Highest Waves H1 3 12 5 1 2 Significant Wave Height Calculated from Standard Deviation HS 12 5 1 3 Significant 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_SPE...

Page 4: ...ace 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 Configurator 46 10 Troubleshooting 50 11 Appendix A Mechanical Assembly 57 ...

Page 5: ...he 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 betwe...

Page 6: ...X 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 Resoluti...

Page 7: ...he 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 5 Grey GND Signal ground 6 Pink CAN H CAN2 0B high signal optional 7 Blue CAN L CAN2 0B low signal ...

Page 8: ... This requirement must be specified 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 inte...

Page 9: ...on ground Maximal voltage applied to the sink can go up to 30 VDC providing greater flexibility in connection of the sensor to PLCs loggers or data concentrators Signal range and function for 4 20 mA analog output can be configured 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 t...

Page 10: ...face 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 ...

Page 11: ...he water surface is 90 When mounting the sensor special care must be taken to ensure that a direct non obstructed line to the water surface is available Any close object in the vicinity of the sensor can reduce accuracy and introduce offsets or errors in measurements Vibrations of the mounting structure can also affect measurements and should be reduced by any applicable means Picture 5 shows how ...

Page 12: ...ecommended way If there is slight or moderate roughness waviness of the water surface below the sensor the amount of reflected radar signal will be reduced This will reduce SNR Signal to Noise Ratio on the radar echo curve but in most cases won t affect measurement accuracy Strong turbulent flow with high water roughness will reduce measurement accuracy due to the unpredictability of the water sur...

Page 13: ...ct the water surface so it is not as reflective as when there is no precipitation thus reducing the SNR of the returned radar signal However Geolux LX 80 level meters are tested and calibrated to measure the distance to the water level surface even under heavy rainfall Influence of the wind on the accuracy is in most cases neglectable The only exception is strong wind which creates surface waves t...

Page 14: ...ss of the surface determines the ratio in this case In the case of level meters where the incident angle of the transmitted radar beam to the water is around 90 most of the power is reflected back to the sensor and only a small portion of the transmitter power will be dispersed in all directions The ratio between the power reflected to the sensor and the power dispersed in all directions is depend...

Page 15: ...ance as 6 02 m the sensor height will be calculated as the sum of these two values 6 02 m 1 34 m 7 36 m In this case the sensor will report 6 02 m as the measured level and 1 34 m as the measured relative level 4 7 Units Default measurement unit of the LX 80 15 10 Hz is millimetres It is possible to change the measurement unit of the device using any of the aforementioned communication protocols T...

Page 16: ...e radar sensor calculates and reports the following wave parameters in addition to the measurements reported by the standard version of LX 80 water level meter 5 1 Significant Wave Height 5 1 1 Significant Wave Height as an Average of 1 3 of Highest Waves H1 3 The original method for calculating the significant wave height analyses the time domain water level measurements From the time domain wate...

Page 17: ... method uses moments of the power spectrum of the water level measurements to calculate the zero up crossing period using the following formula where M0 and M2 are the zeroth and second spectral moment 5 2 3 Crest Period Calculated from Time Domain Data TCREST The crest period is calculated from the time domain measurements of the water level data by counting the number of crests local maxima and ...

Page 18: ...inimum Water Level LMIN This is the minimum water level as measured by the level radar within the time period as defined by the Wave Analysis Length parameter 5 3 2 Maximum Water Level LMAX This is the maximum water level as measured by the level radar within the time period as defined by the Wave Analysis Length parameter 5 3 3 Mean Average Water Level LMEAN This is the average water level as mea...

Page 19: ...ger lines may introduce errors in transferred data The default instrument RS 232 baud rate is 115200 bps RS 485 baud rate Configures the baud rate bits per second for serial communication on RS 485 data line This setting controls how many bits are sent on the communication line in one second The available values are standardised Using higher baud rates over longer lines may introduce errors in tra...

Page 20: ...n parity is set to None no parity is used and no error detection is possible on bit level When parity is set to Odd parity an additional bit is added to the communication that will be set to 1 when there is odd number of bits with value 1 in the 8 bit payload byte Similarly when parity is set to Even parity an additional bit is added to the communication that will be set to 1 when there is even nu...

Page 21: ... then maximum value for 4 20 mA output can be left to the instrument maximum Processing Parameters Filter Type Changing the type of filter which is used to smoothen the measured data No filter No filtering is used and the raw measurements are reported IIR Infinite Impulse Response filter is used to smooth the data When compared to moving average filter IIR filter reacts more quickly to initial cha...

Page 22: ...ths more measured values are used for filtering and the resulting data will be smoother However when the water level changes it will take more time for the new measurement to be reported Typically this parameter should be set to a value between 10 and 50 For highly turbulent water longer filter length is recommended IIR Constant Q 0 9 Q 0 4 Value IIR The constant used by infinite impulse response ...

Page 23: ...be equal to the wave analysis length divided by 10 For example if the wave analysis length is set to 3600 which is the maximum possible value that will correspond to 360 seconds of data or 6 minutes of data When the radar is turned on and if it is not operating in SDI 12 mode the oceanographic wave measurements will be available over RS 232 NMEA protocol and over Modbus protocol immediately If the...

Page 24: ...l detect water level only within the range set by the Active zone min and Active zone max parameters These parameters is the best way to filter unwanted radar reflections from other structures and objects that are present on the monitoring site that could cause false instrument readings Active zone min It is strongly recommended to set the Active zone min value to the minimum possible distance bet...

Page 25: ...n this parameter should be set to 5 metres Then if the instrument measures that the distance between the instrument and the water is 4 metres it will report that the water level is 1 metre because the water is 1 metre above the gauge zero level For user convenience this parameter can also be indirectly set by inputting the current staff gauge reading Staff Gauge Setting the sensor height relative ...

Page 26: ...e the Geolux Instrument Configurator application to connect to the device within 1 minute after power up If there is no attempt to connect to the device over RS 232 within one minute the device will automatically go back to sleep mode While the device is in sleep mode it consumes only 0 03 W Factory reset Revert the device to default factory settings To fully revert the device to factory settings ...

Page 27: ...ike communication protocol is used to deliver level measurements over the RS 232 interface Detailed description of the protocol is given in chapter 8 of this user manual 7 2 Serial RS 485 Interface Serial RS 485 interface is used for connecting multiple level meters to a single data logger RS 485 interface uses a different protocol then the protocol used over RS 232 interface in order to allow mul...

Page 28: ...l extremely reliable NMEA protocol is unidirectional data is only transmitted from the level meter At RS 232 interface the device periodically outputs following data sentences Level measurement report LVX L1 L2 T1 L3 L4 S1 CSUM CR LF firmware versions up to 2 3 2 LVX L1 L2 T1 L3 L4 S1 S2 CSUM CR LF firmware versions greater than 2 3 2 LVX The keyword sent in the beginning of each detection report ...

Page 29: ...m to excluding these characters Tilt angle report ANG A1 A2 CSUM CR LF firmware versions greater than 2 3 5 ANG The keyword sent in the beginning of each angle report A1 The tilt angle of the instrument along X axis For proper operation of the instrument ensure that this angle is zero or as close to zero as possible between 1 and 1 degrees A2 The tilt angle of the instrument along Y axis For prope...

Page 30: ... way it only outputs the data the servicing protocol is always active To make instrument configuration easy Geolux provides the Geolux Instrument Configurator utility application Regular users do not need to be concerned about the servicing protocol used between the Geolux Instrument Configurator and the level meter device Geolux Instrument Configurator is described in the chapter 9 of this user m...

Page 31: ...e not sent over the interface RS 485 baud rate Configures the baud rate bits per second for serial communication on RS 485 data line This setting controls how many bits are sent on the communication line in one second The available values are standardised Using higher baud rates over longer lines may introduce errors in transferred data The default instrument RS 485 baud rate is 9600 bps set_modbu...

Page 32: ...correspond to 20 mA analog output needs to be set The value is set in the currently configured measurement unit Example if values measured by the instrument are expected to be within the range of 700 mm to 5000 mm it is recommended to configure the maximum value to slightly above 5000 mm for example 6000 mm Alternatively if the resolution is not critical then maximum value for 4 20 mA output can b...

Page 33: ...ue is closer to 0 0 the filter response will be slower When the IIR constant value is closer to 1 0 then the filter response will be faster Amplitude threshold Setting the minimum amplitude of the spectral peak in signal analysis algorithm required to detect peak and report distance If no peak above this value is detected the sensor will report distance equal to 0 The threshold is used to filter n...

Page 34: ...ed level value The default measurement unit is millimetres When changing the measurement unit it s important to make sure that other parameters which depend on the measurement unit such as active zone parameters are also changed to the new unit Level offset Changes the measurement level offset This value should not be changed Active zone min This parameter limits the operational range of the instr...

Page 35: ...d then use this application to connect to the device within 1 minute after power up If there is no attempt to connect to the device over RS 232 within one minute the device will automatically go back to sleep mode While the device is in sleep mode it consumes only 0 03 W Operation mode Switching the device from operating mode to standby mode and back While the device is in standby mode it will com...

Page 36: ...1 filter_type 2 averaging_frame_number 15 spectrum_amplitude_threshold 0 peak_detector 0 RX_gain 216 unit_type 0 wave_analysis_lenght 300 iwr_status 1 bandwidth 0 nmea_protocol_flags 3 force_calibration 1 level_range 15000 0 measurement_frequency 1 0 level_offset 0 0 deadzone_min 200 0 deadzone_max 15000 0 analog_output_min 0 0 analog_output_max 15000 0 IR_constant 500 0 sensor_height 0 000 Retrie...

Page 37: ...me Address Fun Data Start Address Register Count CRC16 Length 1 byte 1 byte 2 bytes H L 2 bytes H L 2 bytes L H Example 0X01 0X03 0X00 0X00 0X00 0X01 0X84 0X0A Table 5 Request Example Name Content Detail Address 0X01 Slave address Sensor id Function 0X03 Read holding register Data start address 0X00 The address of the first register to read minus one HIGH 0X00 The address of the first register to ...

Page 38: ...d be changed in the field In Tables 7 and 8 field Fun corresponds to Modbus function codes i e 0X03 Read holding register and 0X05 Write holding register Table 8 Retrieving Data from the Sensor Fun Register Address Data Length Data Range Details 0X03 0x0001 2 bytes 0 device range mm Current level measurement 0x0002 2 bytes 0 device range mm Average level measurement 0x0003 2 bytes 0 9600 1 38400 2...

Page 39: ...ault 0 4 20 mA minimum value in selected unit 0x0010 2 bytes 0 device range default device range unit 4 20 mA maximum value in selected unit 0x0011 2 bytes 0 device range unit Level measurement offset 0x0012 2 bytes 0 1000 IR filter constant 0x0015 2 bytes 2 printable characters Serial number 0 1 0x0016 2 bytes 2 printable characters Serial number 2 3 0x0017 2 bytes 2 printable characters Serial n...

Page 40: ...5 2 bytes 0 SDI 12 mode 1 Continuous scanning Number of FFT samples 0x0028 2 bytes 0 Maximum peak 1 Last peak Peak detector type 0x0029 2 bytes Standard deviation Standard deviation of measurement 0x002A 2 bytes 0 360 x axis tilt angle in degrees 0x002B 2 bytes 0 360 y axis tilt angle in degrees 0x002D 2 bytes 0 All sentences are sent 1 WAV is not sent 2 ANG is not sent 3 WAV and ANG are not sent ...

Page 41: ...ength TCREST in tenths of second 0x0039 2 bytes 0 wave analysis length TCREST_SPEC in tenths of second 0x003A 2 bytes 0 wave analysis length TPEAK in tenths of second 0x003B 2 bytes 32768 32767 LMIN in current units 0x003C 2 bytes 32768 32767 LMAX in current units 0x003D 2 bytes 32768 32767 LMEAN in current units 0x003E 2 bytes 32768 32767 LMED in current units ...

Page 42: ...op bits 4 even parity 1 stop bit 5 even parity 2 stop bits RS 485 parity and stop bits 0x0007 2 bytes 1 65535 SDI 12 ID 0x000B 2 bytes 1 1000 default 100 Filter length 0x000C 2 bytes 1 65535 default 0 Minimum spectrum amplitude threshold used for detecting peaks 0x000D 2 bytes 0 device range default 0 Active zone minimum 0x000E 2 bytes 0 device rang default device range Active zone maximum 0x000F ...

Page 43: ...r height above the riverbed 0x0023 2 bytes Staff gauge Staff gauge measurement used to indirectly determine sensor height Sensor height staff gauge current measured distance from sensor to water 0x0024 2 bytes 0 Operating mode 1 Standby mode Power management 0x0025 2 bytes 0 SDI 12 mode 1 Continuous scanning Operation mode 0x0026 1 Recalibrate the instrument 0x0027 0 max distance Save background u...

Page 44: ... sensor version fff where fff is firmware version ssssss device serial number Start verification aV a00001 CR LF One value is ready imminently Send data aD0 a d CR LF d verification 0 not ready 1 ready Additional data aD1 aD9 a0 CR LF No values are returned for addi tional data Start measurement aM aMC ammm8 CR LF 8 values are ready within mmm seconds Send data aM aD0 a f f d d d d f f CR LF a f f...

Page 45: ...vel LMAX f average water level LMEAN f median water level LMED Aditional data aD2 aD9 a0 CR LF a0 CRC CR LF No values are returned for additional data Start measurement aM2 aMC2 ammm3 CR LF 3 values are ready within mmm seconds Concurrent measurement aC2 aCC2 ammm3 CR LF 3 values are ready within mmm seconds Send data aM2 aD0 a f f f CR LF a f f f CRC CR LF f significant wave height HS_M0 f zero u...

Page 46: ...t sensor height value aXGSHR a f CR LF f sensor height above riverbed Set sensor height value aXGSHR f a f CR LF f sensor height above riverbed Set current staff gauge reading aXGSGR f a f CR LF f current staff gauge reading device will calculate sensor height above riverbed as staff gauge reading distance from sensor to water Get average time in second for level aXGLAV a f CR LF f averaging time ...

Page 47: ...k detector type aXGPDT t a t CR LF t identifies the peak detector type can be any of the following 0 report the distance to the maximum peak which corresponds to the maximum radar signal reflection 1 report the last peak which corresponds to the furthest reflection from the radar this may include multipath reflections in typical cases and should be avoided Get wave analysis length aXGWAL a f CR LF...

Page 48: ...ing to the instrument from the PC application after issuing this command the instrument will wake up and remain in active state for 60 seconds During that time a connection over serial cable can be established using Geolux Instrument Configurator PC application If the connection is established within this 60 second period the instrument will remain in the active state as long as the PC application...

Page 49: ... continuous calibration value 0 turned off 1 turned on Set force continuous calibration value aXGFCL d a d CR LF d force continuous calibration value 0 turned off 1 turned on Device supports all other commands required by SDI 12 v1 3 and will respond to them but all relevant data can be acquired using the commands from the table above ...

Page 50: ...the upper left corner and select Level meter from the window which appears In the next window select the appropriate COM port and interface If RS 485 interface is selected additionally select the baud rate and the Modbus ID In case of multiple devices connected on a single RS 485 bus make sure that each device has a unique Modbus ID When the Connect button is clicked Geolux Instrument Configurator...

Page 51: ...layed Interfaces RS 232 baud rate RS 232 settings RS 485 baud rate Modbus ID Modbus parity Modbus stop bits SDI 12 ID 4 20 mA min 4 20 mA max Processing Filter type Filter length IIR constant Amplitude threshold Peak detector type Wave analysis length Measurement Level unit Level offset Active zone min Active zone max Sensor height Power management Operation mode Continuous calibration A detailed ...

Page 52: ...e echo curve plot shows the current echo curve in yellow as well as the background echo curve in blue The user can choose to clear the background by clicking the Clear background button or set the background echo curve to a desired distance by clicking the Set background button After setting or clearing the background echo curves should be reloaded by clicking the Reload echo curve button Echo cur...

Page 53: ...ew tab and clicking the Start button enables the user to view the raw data which is being transmitted by the device Clicking the Stop button stops the acquisition of the raw data while clicking the Clear button clears the previously acquired data Picture 10 Geolux Instrument Configurator Raw Data View ...

Page 54: ... at least 500 mA of current 3 Check RS 232 connector The yellow green and grey wires from the instrument cable must be properly connected to the serial port on the computer Make sure that the grey wire signal ground is connected the RS 232 connection will not work if the signal ground is not connected Also make sure that the yellow device Rx and green device Tx are properly connected If you are us...

Page 55: ... to open 7 Try restarting the application and or the computer Close and reopen the configurator application and try to establish the connection again Restart your computer and try to establish the connection to the instrument again The instrument does not respond over Modbus RS 485 interface 1 Make sure that the cable is properly connected to the instrument Check that the cable M12 circular connec...

Page 56: ...evice must have a unique slave device ID assigned so that the bus master can distinguish between the devices If two or more devices are assigned the same slave device ID a bus conflict will happen and prohibit the master to correctly communicate with the slave devices To resolve this problem change the instrument s slave device ID to a unique number through the Geolux Instrument Configurator PC ap...

Page 57: ...s connected to the sensor it will remain in operating mode To change between regular operating mode Continuous scanning and SDI 12 mode SDI 12 automatic sleep change the Power management parameter in the Settings tab The instrument does not respond over SDI 12 interface 1 Make sure that the cable is connected properly to the instrument Check that the cable M12 circular connector is firmly connecte...

Page 58: ...communicate with the slave devices To resolve this problem change the instrument s SDI 12 device ID to a unique value through the Geolux Instrument Configurator PC application The instrument consumes too much power while operating in SDI 12 mode it does not reduce power between two SDI 12 Measure Commands 1 Switch the instrument from operating mode to standby mode Establish a connection to the dev...

Page 59: ... angle the radar beam should be perpendicular to the water surface Both tilt angles should be zero degrees or not bigger than 2 in any direction 2 Check that there are no obstructions between the instrument and the water surface There should be no obstructions between the instrument and the water surface so that the radar waves can freely travel from the instrument s antenna to the water surface a...

Page 60: ...er surface is outside of the predefined active zone the instrument will not be able to report the correct distance Modify the active zone parameters so that the actual distance to the water surface is within the active zone 6 Re calibrate the device If none of the above mentioned suggestions have helped resolve the problem perform device re calibration The instrument has the capability to perform ...

Page 61: ...118 M001 Geolux LX80 Level Metar Assembly drawing R D 1 A 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 B C D E F A B C D E F Ø65 Ø 80 73 36 5 63 22 6x M3 24 38 62 70 80 Dept Technical reference Created by Approved by Document type Document status Title DWG No Rev Date of issue Sheet 08 2021 RevC FINAL Product assembly drawing 1 1 Anodized AL6061 GLX2018118 M001 Geolux LX80 Level Metar Assembly drawing R D 1 A 2 ...

Page 62: ...2022 ...

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