English Operating Instructions Surface Velocity Radar OTT SVR 100
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Table of contents 1 Scope of supply 4 2 Order numbers 4 3 Basic safety instructions 5 4 Introduction 6 5 Installing the OTT SVR 100 9 5.1 5.2 5.3 5.4 5.5 5.6 Criteria for selecting a suitable installation location Information on supply voltage Compatible cable types Installing the OTT SVR 100 Connecting the OTT SVR 100 to the data logger Information on using the RS-485 interface 6 SDI-12-commands and responses 6.1 Overview of standard SDI-12 commands 6.2 Standard commands 6.
1 Scope of supply ! OTT SVR 100 – Radar sensor for contactless measurement of the surface velocity of a flowing waterway; with RS-232- and RS-485-interface (SDI-12- or Modbus protocol) – Installation accessory kit (two-piece swivel mount, consisting of device and wall brackets, and four M8 hexagon bolts) – Connecting cable, 10 m; with 12-pin angled connector – Quick guide – Acceptance test certificate (FAT) 2 Order numbers ! OTT SVR 100 OTT SVR 100 radar sensor – RS-485 interface with SDI-12 protocol (pr
3 Basic safety instructions ! Before commissioning the OTT SVR 100, read these operating instructions and the quick guide enclosed with the device. Ensure you are very familiar with how to install and operate the OTT SVR 100. Retain these operating instructions for subsequent reference ! The OTT SVR 100 is used for contactless measurement of the surface velocity of a flowing waterway. Only use the OTT SVR 100 as described in these operating instructions.
4 Introduction The OTT SVR 100 radar sensor is used for continuous contactless measurement of the surface velocity of a flowing waterway (= index velocity). A connected data logger can use this index velocity (preferably measured in the area of the maximum velocity) to calculate the flow using the "velocity index method". The water level that is also required for this calculation can be determined using any water level sensor (e.g. pressure probe or OTT RLS radar level sensor).
The transmission aerial has a horizontal opening angle of 12° and the vertical opening angle is 24°. The resulting sensor radar footprint can be found in the example applications in Figures 3 and 4 and the table in Chapter 5.1. A swivel mount allows easy, problem-free installation, even on unsuitable surfaces. The electrical connection is via a factory-assembled 12-pin angled connector and a mounting socket. Fig. 2: OTT SVR radar sensor overview.
Fig. 4: Example application 2: OTT SVR 100 installed on an auxiliary structure, e.g. a cantilever arm. The projection of the OTT SVR 100 radar footprint on the water surface is elliptical. In the example shown here, the water level is determined using a contactless OTT RLS radar sensor.
5 Installing the OTT SVR 100 WARNING Risk of explosion due to spark formation and electrostatic charge If the OTT SVR 100 is operated in an explosive atmosphere, there is a risk of the atmosphere igniting. This can cause an explosion involving a risk of very severe injury and damage. ! Never operate the OTT SVR 100 in potentially explosive areas (e.g. waste water channels).
! An optimum measuring point has a uniformly shaped cross-section with an even velocity distribution and a stable position of the maximum surface velocity. ! Avoid large metallic surfaces close to the sensor radar footprint (reflections from these surfaces can falsify the measured result). ! Table for determining the approximate size of the sensor radar footprint: Height "h" [m] 1.0 2.0 3.0 4.0 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 Distance "a" Tilt angle 30° [m] l x w [m] 1.7 3.5 5.2 6.9 8.7 13.
! Wave height measurement using the OTT SVR 100 is not possible. ! The OTT SVR 100 and OTT RLS can be combined at a single measuring point with no problems as they do not influence one another. Likewise, multiple OTT SVR 100s can be used in parallel on very wide flowing waterways. Hight „h”: 0.5 … 25 m (17 m*) Fig. 7: Maximum distances of OTT SVR 100 to water surface. ma x. 50 m * ! = 20° Distance „a“ (centre of sensor radar footprint) 5.
5.4 Installing the OTT SVR 100 Attaching the swivel mount (see also Appendix C) ! Surface: Concrete or brickwork ! Attachment material: e.g. hexagonal wood screws M6 x 40 + plastic dowels " Make two holes (Ø 8 mm) using a hammer drill (use the wall bracket for marking the holes). " Insert the plastic dowels into the drill holes. " Attach the wall bracket with hexagonal wood screws. " Mount the housing bracket (without sensor) in the wall bracket and slightly tighten the hexagon bolts A (see Fig.10).
Connecting the cable with angled connector Please note: No moisture may get into the angled connector/the mounting socket. Protect the OTT SVR 100 from precipitation during installation. Ingress of moisture can lead to malfunctions and corrosion. " Align the angled connector in the correct position (observe keying nose) and fit on the mounting socket. " Where possible, tighten the union nut by hand if using a fork wrench. Tightening torque max. 2 Nm. The union nut engages when tightened.
Fig. 10: OTT SVR 100 – Installation of swivel mount.
Fig. 11: Adjusting the sensor tilt angle (!) on the OTT SVR 100.
5.5 Connecting the OTT SVR 100 to the data logger " Connect the OTT SVR 100 to an SDI-12 input on the data logger. Refer to the data logger manual for more details. Refer to Figure 12 for the OTT SVR 100 terminal assignment. The maximum cable length is 1000 m. Recommended wire cross-section: see Chapter 5.3. The SDI-12 commands that can be used with the OTT SVR 100 can be found in Chapter 6, SDI-12-commands and responses. Fig. 12: Wire assignment in connecting cable (12-wire).
6 SDI-12-commands and responses The OTT SVR 100 communicates using the physical RS-485 interface via the SDI-12 transfer protocol. In this technical documentation, you will find a detailed description of the SDI-12 commands implemented in the SDI-12 transfer protocol. Further information on the SDI-12 standard can be found in the document "SDI-12; A Serial-Digital Interface Standard for Microprocessor-Based Sensors; Version 1.3" (see website "www.sdi-12.org").
6.
Command Response Description – Vibration index Format: +00b [1] +000 = No device vibration +001 = Slight device vibration +002 = Significant device vibration ➝ impaired measured values +003 = Very significant device vibration; ➝ unacceptable measured values aR0! a … … … … aMC! atttn aC! atttnn aCC! atttnn aV! atttn aD0! a The OTT SVR 100 continuously measures the flow vel
6.2 Advanced SDI-12 commands Command Response Description ! Set/read internal filter type aOAA! aOAA! a aCalculation Set internal filter type Read internal filter type a – Sensor address – 0 = IIR filter (Infinite Impulse Response filter) 1 = Floating mean Factory setting: 1 The OTT SVR 100 determines approx. 20 individual measured values for the flow velocity per second.
Command Response Description ! Set/read flow direction filter aOSD! aOSD! a a Set flow direction filter Read flow direction filter a – Sensor address – 0 = Filter is deactivated ➝ The OTT SVR 100 determines the flow velocities towards sensor and away from the sensor. The value 4 (–1/+1) in the response to the aD0! command shows the corresponding flow direction.
7 Performing maintenance work The OTT SVR 100 radar sensor is largely maintenance free. No adjustment or calibration work is necessary. Likewise, it has no parts that have to be cyclically replaced. The following maintenance work should be performed at regular intervals, according to your local conditions: " Check the OTT SVR 100 for soiling (e.g. dense, dew-covered spiders’ webs or insect nests can lead to negative impairment of the measured results).
9 Information on disposal of old devices Within the member states of the European Union In compliance with the Electrical and Electronic Equipment Act (ElekrtroG; national implementation of EU Directive 2002/96/EC) OTT will take back and properly dispose of old devices in the member states of the European Union. Affected devices are indicated by the adjacent symbol. " For further information about the return procedure, please contact your local sales contact.
10 Troubleshooting Sensor not responding to RS-485 interface ! Sensor correctly connected to a data logger with SDI-12-input (master)? ➝ Correct terminal assignment. ! Supply voltage polarity reversed? ➝ Correct terminal assignment. ! Supply voltage < 9 V or > 27 V? ➝ Correct supply voltage level (check length and cross section of connecting cable). ! Can the supply voltage used deliver1 A output current? ➝ Use a suitable supply voltage.
11 Technical Data Measuring range Resolution Measuring accuracy Measuring time 0.08 … 15 m/s 0.1 mm/s ±2 % of measured value Continuous measurement Supply voltage Current consumption Typical Maximum 9 … 27 VDC < 112 mA bei 12 V < 250 mA Transmission frequency (min./typ./max.) Transmission power Antenna opening angle Azimuth (horizontal angle; 3 dB) Elevation (vertical angle; 3 dB) 24.050/24.125/24.
Appendix A – Connecting the OTT SVR 100 to OTT netDL via the RS-485 interface Connect the OTT SVR 100 using the physical, RS-485 interface (SDI-12 protocol via physical RS-485 interface). Refer to Chapter 5.3 for the maximum cable length and recommended wire cross-section. " Connect the OTT SVR 100 to the OTT netDL IP data logger as shown in Figure A1. Also refer to the OTT netDL operating manual. Fig. A1: Connecting OTT SVR 100 to OTT netDL via RS-485-interface (SDI-12-protocol).
! Measured value no. ! ! ! ! " Indicates which value from the OTT SVR 100 will be recorded on this channel. Average flow velocity = 1, Current flow velocity = 2, Sensor tilt angle = 3, Flow direction = 4, Signal quality index = 5, Vibration index = 6 Measuring mode M! (C!); for measured values average flow velocity, current flow velocity, sensor tilt angle, flow direction, signal quality index and vibration index.
Appendix B – Wall bracket dimensions/mounting hole positions 137 4 35 17 23 Ø 67.5 134.5 8.5 7 12 114.
Appendix C – Note on the declaration of conformity If required, you can download the current version of the declaration of conformity for the OTT SVR 100 from our website as a PDF file: "www.ott.com/resources".
Appendix D – RS-485 interface with Modbus protocol (RTU) D.1 Prerequisites ! Transmission parameter ! Transmission speed ! RS-485 interface protocol 1 stop bit, even parity Factory setting: 9 600 Modbus D.
Register name Registernumber Type Value range ! RS-232 protocol 0011 unsigned word 1➝ NMEA ! RS-485 protocol 0012 unsigned word 1 ➝ Modbus 2 ➝ SDI-12 Fartory setting Accessmode Unit R [1] 2 R [1] D.
Appendix E – OTT SVR 100 Operating Program The "OTT SVR 100 Operating Program" PC software is available for service purposes. You can use this software to establish a temporary connection to the OTT SVR 100 via the RS-232 interface and ! set OTT SVR 100 operating parameters ! perform a firmware update ! start a continuous measurement and represent flow velocity measured values graphically If necessary, download the latest version of the operating program (setup file) from "www.ott.com/resources".
" Set operating parameters: Select "Setup" tab, set required parameters and click on "Write" ➝ The operating program writes the changed parameters to the OTT SVR 100. You can find a description of the parameters in Chapter 6 "SDI-12 commands and responses", additional parameters "RS-485 protocol": Protocol on the RS485 interface, either "SDI-12" or "Modbus RTU". " Update firmware: Select the "Setup" tab and click on "Select firmware..." ➝ The operating program opens a new window. Select the firmware file (.
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