Geolux RSS-2-300W User Manual

Non-contact surface velocity radar

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RSS-2-300W

Non-Contact

Surface Velocity Radar

User Manual

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Page 2 Starting Point Thank you for purchasing Geolux RSS-2-300W non-contact surface velocity radar! 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.
Page 3: Table Of Contents
Data Interface 6.1. Serial RS-232 Interface 6.2. Serial RS-485 Interface Data Protocols 7.1. NMEA Protocol (RS-232) 7.3. Request-Response Protocol (RS-485) 7.3.1. Request-Response Protocol (RS-485) 7.4. Modbus Protocol (RS-485) Geolux Instrument Configurator Calculating Discharge from Flow Velocity Troubleshooting Appendix A – Mechanical Assembly...
Page 4: Introduction
RSS-2-300W User Manual Introduction Geolux RSS-2-300W surface velocity radar uses radar technology to provide precise contactless measurement of surface flow velocity. Contactless radar technology enables quick and simple sensor installation above the water surface, and requires minimum maintenance. This functionality is achieved by transmitting an electromagnetic wave in 24 GHz frequency range (K-band), and measuring the frequency shift of the electromagnetic wave reflected from the flowing water surface.
Page 5: Electrical Characteristics
RSS-2-300W User Manual Electrical Characteristics The electrical characteristics of the Geolux RSS-2-300W surface velocity radar are given in Table 1. Table 1. Electrical Characteristics Parameter Unit Communication interface RS-232 interface speed 1200 115200 RS-485 interface speed 1200 115200 Radar sensor Frequency 24.075...
Page 6: Connector Pin-Out
RS-485 data transmitter/receiver high signal Black Alarm SW Alarm - open collector switch signal max. 60mA (optional) Purple 4 – 20 mA Sink for 4 – 20 mA analog interface. Connect sensing device as pull-up to sink the current RSS-2-300W Non-Contact Surface Velocity Radar...
Page 7: Serial Rs-232 Interface
DB-9 connector. Picture 2. Serial RS232 DB-9 Cable Optionally Geolux can supply a cable with DB-9 connector connected to the cable but this must be specified as option when ordering the sensors. Several communication protocols are available, and custom on request. Details of communication protocols are described later in this user manual.
Page 8: Analog 4 - 20 Ma Output
10Ω to 500Ω with recommended value 100Ω for the sensing resistor. Picture 4. High Side Current Measurement for the 4 – 20 mA Analog Output RSS-2-300W Non-Contact Surface Velocity Radar...
Page 9: Installing The Surface Velocity Radar
The structure holding the instrument (pole, bridge fence, etc.) must be solid and without vibrations. There should be no vegetation between the radar and the measurement area because it could affect measurement accuracy. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 10: Measurement Quality Indicator
120 or more. 4.2. Measurement Quality Indicator Geolux RSS-2-300W instrument is constantly calculating various parameters of the signal in the signal processing algorithms and will continuously, along with measurement data, report the measurement quality. Quality indicator value is in range from 0 (the best quality) to 3 (the worst quality) and can be used to interpret data in the analysis software with better understanding and confidence.
Page 11: Interference And Multiple Radars
SNR (signal to noise) ration on the radar which enables more accurate measurement. Geolux surface velocity radar is designed with special techniques to achieve accurate measurements even in the very small SNR environments so the required surface roughness of 1 mm is usually enough for the precise measurements.
Page 12 Indoor applications are generally not recommended as it could lead to wrong readings due to the reflection of the radar beam and hitting any moving or rotating object which could cause false readings. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 13: Surface Velocity Radar Settings
RS-232 interface. The NMEA protocol is a GPS-like human readable messaging protocol where each data packet contains a checksum for data integrity verification. SDI-12 protocol is used for interfacing older type of Geolux SDI-12 adapters. Unless the instrument is connected to an older Geolux SDI-12 adapter, NMEA protocol must be selected.
Page 14 It is recommended to set this value to a minimum of 5 seconds. In extreme cases where a quick response after unit power-up is required, 3 seconds can be used, with a possibility of losing measurement accuracy. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 15 If the instrument is incorrectly reporting flow when there is no water in the channel, it’s necessary to increase the value of this parameter. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 16 However, when the surface velocity changes, it will take more time for the new measurement to be reported. Typically, this parameter should be set to a value between 50 and 200. For highly turbulent water, larger filter length is recommended. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 17 Velocity min. and Velocity max. Velocity min. - This parameter is used for setting up the minimum velocity value of interest. Velocity max. - This parameter is used for setting up the maximum velocity value of interest. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 18: Data Interface
RSS-2-300W User Manual Data Interface Geolux RSS-2-300W surface velocity radar offers multiple data interfaces, in order to make the integration of the device with existing SCADA/telemetry systems easy. 6.1. Serial RS-232 Interface Serial RS-232 interface is used for direct connection of a single surface velocity radar unit with the computer.
Page 19: Data Protocols
RSS-2-300W User Manual Data Protocols Geolux GLX-RSS-2-300W surface velocity radar supports the following data protocols: • NMEA-like protocol on RS-232 interface that constantly outputs the detected speed and reflected signal power, and also the current measured tilt angle • Servicing protocol on RS-232 interface for configuring the unit •...
Page 20 The measured surface velocity with additional average filter applied (velocity is reported as velocity*10 for m/s, km/h, mph, fps and fpm and as velocity*1 for mm/s and cm/s). Geolux Instrument Configurator internally handles the multiplication factor and displays the correct values to the user...
Page 21 RS-232 interface. The NMEA protocol is a GPS-like human readable messaging protocol where each data packet contains a checksum for data integrity verification. SDI-12 protocol is used for interfacing older type of Geolux SDI-12 adapters. Unless the instrument is connected to an older Geolux SDI-12 adapter, NMEA protocol must be selected.
Page 22 700 mm/s to 1500 mm/s, it is recommended to configure the minimum value to slightly below 700 mm/s (for example 500 mm/s). Alternatively, if the resolution is not critical, then minimum value for 4-20 mA output can be left to the instrument minimum of 0 mm/s. #set_420_min=<value> RSS-2-300W Non-Contact Surface Velocity Radar...
Page 23 On monitoring sites where it is expected that the flow will always be in only one direction, it is recommended to properly configure this parameter to either incoming or outgoing, as that will improve the consistency of measurements. #set_direction=in #set_direction=out #set_direction=both RSS-2-300W Non-Contact Surface Velocity Radar...
Page 24 #set_min_velocity=<value> Low power mode - Available only on devices with firmware versions above 6.3.2. This parameter is used for putting radar in low power mode. #radar_sleep RSS-2-300W Non-Contact Surface Velocity Radar...
Page 25: Request-Response Protocol (Rs-485)
Exactly two bytes long. This is the unit ID written as two ASCII characters. For example, if the polled unit ID is 2, then ID will be sent as “02”. In HEX representation it is the following two bytes: <0x30><0x32>. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 26 CSUM: Checksum, calculated by adding in modulo 256 the two byte values of the ID. If the device ID is 2, then ID was sent as <0x30><0x32>. Checksum is then 0x30+0x32 = <0x62>. After receiving the request, device goes to normal operation mode from power safe mode. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 27: Modbus Protocol (Rs-485)
CRC Low 0X0A CRC High Table 5. Slave (sensor) Response Format Name Address Byte Count Data CRC16 Length 1 byte 1 byte 1 byte 2 bytes(H,L) 2 bytes(L,H) Example 0X01 0X03 0X02 0X00 0X01 0X79 0X84 RSS-2-300W Non-Contact Surface Velocity Radar...
Page 28 Read tilt angle 0X0006 2 bytes 0→incoming Read flow direction 1→outgoing 0X0007 2 bytes 1-512 Read filter length 0X0008 2 bytes Read defined PGA gain sensitivity 0X0009 2 bytes 0→both Read flow direction filter 1→incoming setting 2→outgoing RSS-2-300W Non-Contact Surface Velocity Radar...
Page 29 Read averaged SNR level (dBm * 256) 0x0016 – 2 bytes Reserved, always 0 0x001B 0x001C 2 bytes 0-15000 Velocity min. (mm) 0x001D 2 bytes 0-15000 Velocity max. (mm) 0x001E – 2 bytes Reserved, always 0 0x001F RSS-2-300W Non-Contact Surface Velocity Radar...
Page 30 2 bytes 0-100 Change sensitivity level 0X000C 2 bytes 0-3840 Change SNR threshold (dBm * 256) 0x001C 2 bytes 0-15000 Velocity min. (mm) 0x001D 2 bytes 0-15000 Velocity max. (mm) 0x0051 2 bytes Low power mode RSS-2-300W Non-Contact Surface Velocity Radar...
Page 31: Geolux Instrument Configurator
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 will try to establish a data link between your PC and the surface velocity radar. If the connection is successful, the device will appear under Connected devices and the flow velocity measurements will be displayed in the Data tab, Picture 7.
Page 32 RSS-2-300W User Manual Picture 7. Geolux Instrument Configurator Main Window With the Device Connected – Data Clicking the Settings button enables the user to configure the surface velocity radar or upgrade the device to a newer firmware version. The device settings are grouped into 3 groups: Interfaces, Processing and Measurement.
Page 33 Depending on the Direction filter selected in Settings, the echo curve which is not of interest will be shown in grey. If desired, echo curves can be saved to a .csv file. Picture 9. Geolux Instrument Configurator – Echo Curve – Direction Filter Set to Outgoing RSS-2-300W Non-Contact Surface Velocity Radar...
Page 34: Calculating Discharge From Flow Velocity
9. Calculating Discharge from Flow Velocity Geolux RSS-2-300W surface velocity radar measures flow velocity at the water surface. This measurement can be used to calculate actual discharge – the total volume of water that passes through a channel cross-section in a specific period of time. Discharge measurement is important...
Page 35 Knowing non-rectangular area of the stream cross-section, and knowing the surface flow velocity, the following formula can be used: Q = 0.85 * V * A More details about water flow measurements can be found in the following technical note: https://319monitoring.wordpress.ncsu.edu/files/2016/05/technote3_surface_flow.pdf RSS-2-300W Non-Contact Surface Velocity Radar...
Page 36: Troubleshooting
RSS-2-300W User Manual Troubleshooting Geolux RSS-2-300 W surface velocity radar offers multiple data interfaces, in order to make the integration of the device with existing SCADA/telemetry systems easy. Problem Possible solutions The instrument 1. Make sure that the cable is properly connected to the instrument...
Page 37 The default Modbus device ID is 1. The Modbus device ID can be changed by connecting the instrument to the PC application (over RS-232 connection). Connect the instrument to the PC using RS-232 connection. Open the Geolux Instrument Configurator application and establish a connection between the instrument and the PC.
Page 38 These parameters can be changed by connecting the instrument to the PC application (over RS-232 connection). Connect the instrument to the PC using RS-232 connection. Open the Geolux Instrument Configurator application and establish a connection between the instrument and the PC. Then check and verify that all Modbus connection parameters are correct.
Page 39 Use a tape measure or a similar tool to measure the distance between the instrument’s antenna and the water surface. If the distance to the water surface is greater than the instrument’s operational range, the instrument will not be able to measure the surface velocity. RSS-2-300W Non-Contact Surface Velocity Radar...
Page 40: Appendix A - Mechanical Assembly
RSS-2-300W User Manual Appendix A – Mechanical Assembly RSS-2-300W Non-Contact Surface Velocity Radar...
Page 41 2021.