OTT SVR 100 X2 Integration Guide

The OTT SVR 100 is a surface water velocity radar sensor designed for measuring flow in open channels and rivers. The sensor is compatible with the X2 data logger utilizing SDI-12 communication and creating a generic SDI-12 script in the CONNECT software. Simple settings on the sensor may be adjusted using the OTT SVR 100 Operating Program via an RS-232 interface. Below is information on the settings and wiring required to integrate this sensor with the X2 data logger.

Figure 1: OTT SVR 100 Surface Water Velocity Radar Sensor



NexSens can provide a connectorized UW8 plug on the end of the OTT SVR 100 factory cable for integration with an X2 data logger, or a UW8 to flying lead cable may be utilized for wiring into a junction box. The following table refers to the latter application.


NexSens UW8 Plug PinNexSens UW8-FLx Wire Color*SignalOTT Sensor Cable Wire Color
2BlackGroundGrey & White
5Red12V PowerBrown

*NexSens UW Plug to Flying Lead Cable

Figure 2: NexSens UW8 Plug pin numbers.



Configure Communication

An RS-232 USB cable with a separate external power source may be utilized for communication with the OTT SVR 100 sensor in the OTT SVR 100 Operating Program. Default SDI-12 settings do not need changed for communication with the X2 data logger. This operating program allows for viewing real-time data and changing the following settings:

  1. Device SDI-12 address
  2. Filter Type
  3. Filter Length
  4. Radar Sensitivity
  5. Flow Direction Filter
NexSens RS-232 USB Cable Wire ColorSignalOTT Sensor Cable Wire Color
YellowRS-232 TxGreen
OrangeRS-232 RxYellow
BlackGroundWhite & Grey

*No external power source should be connected to the USB cable.
**An external power source must be utilized to provide between 9-27VDC to the sensor. Ensure that the external power source has a common ground with the USB cable and OTT sensor cable.


X2 Script Information & Sensor Parameters

Create a generic SDI-12 script through the CONNECT Software with the following settings:

  • Manufacturer: Generic
  • Model: SDI-12
  • SDI-12 Address: 0-9
    • Ensure the OTT sensor has a unique SDI-12 address from other SDI-12 sensors connected to the X2.
    • The default address for the sensor is 0.
  • Port: P0, P1, or P2
    • Ensure to connect the sensor to the port number selected in the script.
  • Warmup: 40 seconds
  • Measurement Command: C
  • Power: Switch
  • Parameters:
CONNECT Parameter NameUnitsOTT SVR 100
Parameter Name
Velocitym/sMean Velocity of FlowAverage flow velocity over approximately 30 seconds.
Velocitym/sCurrent Velocity of FlowCurrent flow velocity.
Parm 01degSensor Tilt AngleInclination relative to the water surface. Optimal range is between 30 and 45 degrees.
Parm 02Signal Quality IndexQuality of radar signal received for measurement.

0 – Good Signal
3- Very bad signal

Parm 03Vibration IndexMeasure of vibrations in deployment area.

0 – No vibration
3- Very strong vibrations (Data unacceptable)

SNRdBSignal-to-Noise RatioMeasure of desired radar signal to the level of background noise.

>6 – Good signal


Enable the newly generated script by following the article below:

Configure Sensor Scripts