X2 Logger Diagnostic Readings

All X2 data loggers have an internal set of sensors that measure important system health factors, which are called meta parameters or diagnostic readings. A total of (12) X2 meta parameters are collected.

X2 Meta Parameter Descriptions

  1. Processor Power – The 3.3V nominal regulated supply power being fed to the X2’s CPU and other internal components. Typically ranges between 3.2-3.5V.


  1. RTC Power – A real-time clock (RTC) lithium coin battery inside each X2 allows the logger to maintain time when it is powered down or reset. Values of 2.8V-3.3V are acceptable.

Values that fall below 2.8V indicate the battery is beginning to deplete. At a critical level, the battery will no longer be able to keep time and the X2 clock will reset to Jan 1st 1970 at 12am (unix timestamp zero) each time power is reset on the system. To avoid data logging interruptions, it is recommended an X2 be sent to NexSens Technology to replace the RTC battery when it falls to 2.7V or below.


  1. Primary Power – Each X2 is capable of utilizing two independent power inputs for redundancy. Power provided in the following instances will be registered as Primary Power:
    1. Land-based X2 data loggers utilizing an SP-Series solar power pack or UW6-PW AC power adapter.
    2. Buoy-mounted X2-CB systems utilizing the solar charged batteries in the data well.
    3. X2-SDL data loggers accepting power from an SBP500 battery pack (or other external source) via the central 6-pin port on its bottom bulkhead.

Depending on the power source*, the following values are typical:

    1. 12V-15V for SP-Series solar power pack or CB-Series buoys.
    2. Consistent 12.1-12.5V for an AC power adapter.
    3. 8.5V to 12.9V for an SBP500 battery pack, depending on how recently the installed D-cell batteries were replaced.

*If none of these supplies are connected and a secondary power source is used, primary power will read ~0V.


  1. Secondary Power – Any power supplied to an X2 through the secondary pins on a UW-6 plug connector will be registered as Secondary Power.

Secondary power is typically only utilized by X2-SDL systems running on internal D-cell batteries. All other systems will return ~0V (as shown), indicating that no secondary power input is present.


  1. Sensor Power – The X2 regulates power to its sensor ports. Depending on the state of the system’s primary or secondary power, the X2 will boost or reduce sensor power to maintain a nominal 12V output. In practice, these values tend to range from 11.8V-12.2V.


  1. Total System Current – The total power consumption of the electronics in the system (sum of the data logger and external sensors) is monitored by the X2.

It is best to disregard the status icon designation for this parameter. Depending on the system setup (telemetry type, number of sensors, sensor types, etc.) and other system conditions (power supply voltage), a ‘normal’ current draw will vary widely between systems. Instead, use this to establish a baseline and investigate system health if a significant change is observed.


  1. Sensor Current – The current draw, at 12V, of all external sensors and devices connected to an X2 logger.

As with total current, disregard the status icon and use historical data to establish a baseline range for the system’s sensor current.


  1. Internal Pressure* – Reports the air pressure inside an X2 data logger housing. Useful for identifying vent obstructions or excessive outgassing from charging system batteries.

Note that X2 systems delivered any time after mid-2018 will not have an internal pressure sensor due to a parts shortage-induced design change. Dashes will occupy the value field as a result.


  1. Internal Temperature – Registers the ambient temperature inside the housing of the X2 logger.


  1. Internal Humidity – Reflects the amount of moisture in the air inside the X2 housing.

Acceptable values will range from a slight negative percentage (effectively zero) up to ~50%. If humidity is reported to be greater than 50%, the desiccant bag inside the X2 or X2-CB should be replaced and the enclosure seal inspected. High humidity can contribute to telemetry problems and, in more extreme cases, damage the logger circuitry.


  1. Cell Signal Strength – Despite the name, cell signal strength is representative of the transmission signal strength for all telemetry-enabled X2s including radio and Iridium satellite.

Expected values are as follows:

      1. Cellular systems
        1. -51 to -79 dBm for strong signal strength (~4-5 bars equivalent)
        2. -80 to -89 dBm for moderate signal strength (2-3 bars equivalent)
        3. -90 to -99 dBm for weak signal strength (1-2 bar equivalent)
        4. At -100 dBm or lower, connections will be intermittent at best
      1. Iridium satellite systems
        1. The value reflects the number of Iridium satellites the system can currently see
        2. 5 is the maximum corresponding with the strongest possible signal
        3. 0 is the lowest value, and connections typically fail at this level


  1. Cell Status – Error codes from a failed or compromised X2 data transmission attempt will be displayed in the cell status field. As with cell signal strength, the cell status parameter applies to all telemetry types including cellular, radio, Iridium satellite, and Wi-Fi. Values of zero indicate that no errors were observed.

If status errors appear frequently and data transmissions are affected, contact NexSens Technology and supply the status error code for troubleshooting.