X3-SUB Logger SIM Card Installation

The cellular model of the X3-SUB Submersible Data Logger contains an internal modem for cellular telemetry. The SIM card slot on the modem is compatible with 4G-capable SIM cards that are a 3FF SIM size (12 x 15 mm; Micro-SIM). Before purchasing or installing a SIM card, ensure the SIM is set up according to the article below:


Installation Instructions

Before installing a SIM card, ensure the logger is disconnected from all power sources. Statically ground yourself prior to and while contacting any of the electronics inside the logger. Failure to do so may result in a static discharge that can be harmful to the electronics.

  1. Use a Phillips-head screwdriver to remove the (6) screws holding the top plate of the X3-SUB.

Figure 1: Remove the (6) scripts from the X3-SUB.


  1. Use the handle to lift up slowly on the top plate. Disconnect the Molex connection to the internal battery.

Figure 2: Disconnect the top plate from the well.


  1. Locate the modem on top of the circuitry to the right of the gold RF antenna cable. Orient the SIM, as shown in the image, and insert it into the SIM card slot.
    1. Note: All X3-SUBs ship with a pre-installed SIM card. Remove the current SIM card before installing the new one.

Figure 3: Remove the NexSens-provided SIM card.

Figure 4: Insert the new SIM card.


  1. Re-connect the Molex connection with the internal battery and align the top plate with the threaded bolt holes on the well.
    1. It is recommended to apply a light layer of O-ring grease to the O-ring before tightening down the top plate.

Figure 5: Re-install the top plate.

Figure 6: Tighten down the top plate to the well.


  1. Follow the link below to set up the cellular telemetry on the X3-SUB:
    1. Enable Cellular Communication on an X-Series Data Logger