X3-SUB Submersible Data Logger Overview

The X3-SUB is a rugged, self-powered remote data logger system specifically designed for offshore use without fear of accidental flooding. It automatically recognizes sensors and sends data to the WQData LIVE web data center via cellular or satellite telemetry. There, data is presented on a fully-featured and easy-to-use dashboard where remote, real-time communication with the logger is possible. The X3-SUB includes three MCIL/MCBH wet-mate sensor ports that are compatible with most environmental sensors using SDI-12, RS-232, or RS-485. All connections are made with a simple thread-on connector, and the built-in sensor library automatically facilitates setup and configuration. Data is stored on common or independent schedules.

The X3-SUB can be powered by an internal SLA battery, alkaline battery pack, or external 12VDC power. The internal SLA battery is intended for use with the CB-75 Data Buoy for continuous power via solar charging. Advanced power management combined with ultra-low sleep and run currents extend battery life and eliminate the need for multi-battery arrays or large solar charging systems. The X3-SUB monitors itself while collecting environmental data – internal temperature, humidity, voltages, and currents are constantly recorded, and failure alerts can be sent automatically to a predefined list of contacts.

Using Bluetooth or a USB adapter with the NexSens CONNECT Software, users can configure the X3-SUB for deployment, view live data, change settings, or troubleshoot. Optional integrated 4G LTE cellular or Iridium satellite telemetry modules offer 2-way remote communications via the WQData LIVE.

Figure 1: X3-SUB Submersible Data Logger


Body Tag Identification

Each X3-SUB logger has an identifier label placed on the top plate of the logger. The identifier label includes important information, such as the Body Tag. The tag is incorporated into the default name of the device on WQData LIVE and is used for logger identification. A NexSens technical support specialist will request this tag for remote troubleshooting or if NexSens-supplied data services require activation, suspension, or cancellation.

Figure 2: X3-SUB body tag identification.



The X3 is fully sealed in a marine anodized aluminum housing. All sensor and power inputs utilize waterproof UW connectors, and antenna connections feature an O-ring seal. The unit is designed to work in extreme conditions, including underwater. A specially designed mounting bracket holds the X3 to a pole mast, and bolt holes on the top and bottom of the housing provide easy installation on NexSens CB-Series data buoys.

  • Material: Type 316 stainless steel
  • Weight: 12.0 lbs. (5.44kg)
  • Dimensions: 5.5″ (13.97cm) diameter with 7.25″ (18.42cm) flange x 13.63″ (34.62cm) height
  • Rating: IP68
  • Operating Temperature: -40°C to 70°C
  • Antenna Port: Type N female
  • User Interface: Wireless Bluetooth or wired RS-485 via USB adapter to CONNECT Software; WQData LIVE Web Datacenter with optional wireless telemetry; Status beeps
  • Log Interval: User configurable from 1-minute (10-minute default)1; Unique interval per sensor
  • Transmit Interval: User configurable from 5-minute (10-minute default)
  • Transmission Trigger: Time-based; Selective parameter upload option
  • Sensor Interfaces: RS-232 (3 Channels), SDI-12, RS-485, Pulse Count
  • Sensor Power: (2) independent switches from the input supply2,3
  • Telemetry Options: 4G LTE global cellular; Iridium satellite
Internal Features
  • Internal Power: 6 A-Hr SLA battery, 12 VDC
  • External Power Requirements: 10.7 to 16.8 VDC +/-5%; includes reverse polarity protection, over voltage protection (OVP), and under voltage lock out (UVLO) protection
  • Current Draw (Typical @ 12VDC): Sleep: 450uA; Active: 55mA; Cellular transmitting: 300mA; Iridium satellite transmitting: 170mA
  • Peak Current: Power supply must be able to sustain a 500mA 1-second peak current (@ 12V)
  • Real-Time Clock (RTC): <30sec/month drift4; Auto-sync weekly5; Internal backup battery
  • Data Logging: 8 MB non-volatile flash memory; > 1-year storage with 20 parameters at 15-minute intervals; Max 200 parameters per log interval
  • Built-in Sensors:
    • Temperature (-40° to 100°C, 0.016°C resolution, ±0.3°C accuracy)
    • Humidity (0% to 100%, 0.03% resolution, ±4% accuracy from 5 to 95% RH)
    • System voltage
    • System current
    • System power
    • Real-time clock (RTC) battery voltage
  • Sensor Ports: (3) MCBH-8-MP for sensor interface (RS-232, RS-485, SDI-12, Power, GND)
  • Power Port: (1) MCBH-6-FS for power and communication (12V Solar In, Power Switch, RS-485 Host, GND)

1Minimum log interval dependent on sensor limitations and processing time
2Cumulative concurrent current limit of all three channels is 2A
3Logger power supply must be able to support current requirements of sensors
4Assumes 25°C operating temperature
5Requires the X3 to be connected to the internet