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
Wiring
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 Pin | NexSens UW8-FLx Wire Color* | Signal | OTT Sensor Cable Wire Color |
2 | Black | Ground | Grey & White |
5 | Red | 12V Power | Brown |
6 | Brown | SDI-12 | Red |
*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:
- Device SDI-12 address
- Filter Type
- Filter Length
- Radar Sensitivity
- Flow Direction Filter
NexSens RS-232 USB Cable Wire Color | Signal | OTT Sensor Cable Wire Color |
Yellow | RS-232 Tx | Green |
Orange | RS-232 Rx | Yellow |
Black | Ground | White & Grey |
–* | +9…+27VDC | Brown** |
*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 Name | Units | OTT SVR 100 Parameter Name | Description |
Velocity | m/s | Mean Velocity of Flow | Average flow velocity over approximately 30 seconds. |
Velocity | m/s | Current Velocity of Flow | Current flow velocity. |
Parm 01 | deg | Sensor Tilt Angle | Inclination relative to the water surface. Optimal range is between 30 and 45 degrees. |
Parm 02 | — | Signal Quality Index | Quality of radar signal received for measurement. 0 – Good Signal |
Parm 03 | — | Vibration Index | Measure of vibrations in deployment area. 0 – No vibration |
SNR | dB | Signal-to-Noise Ratio | Measure of desired radar signal to the level of background noise. >6 – Good signal |
Enable the newly generated script by following the article below: