> For the complete documentation index, see [llms.txt](https://tankmate.gitbook.io/tankmate/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://tankmate.gitbook.io/tankmate/tankmate-user-guide/tankmate-r3-lte-cellular-sensors/hardware-status-r3l-cellular-lte-sensor.md).

# Hardware Status - R3L Cellular / LTE Sensor

### Check device connectivity with the status LED

* Remove the **four fixing screws** (#2 Philips) that secure the sensor to the tank
* Lift the sensor up from the tank
* **Press** the **READ button** on the underside of the sensor unit, and check the status LED

{% hint style="success" %}
The status **LED** and **buzzer** should follow this sequence:

* blinking <mark style="color:green;">**GREEN**</mark> (connecting to cellular network)&#x20;
* blinking <mark style="color:blue;">**BLUE**</mark> + single **beep** (connecting to the server)
* solid <mark style="color:blue;">**BLUE**</mark> + single **beep** (successful connection to the server)
* blinking <mark style="color:orange;">**ORANGE**</mark> + short **beep** **x 10** (delay before the sensor reads) -> place the sensor back down on the tank to take a tank level reading
  {% endhint %}

{% hint style="warning" %}
If the sensor blinks <mark style="color:red;">**RED**</mark> after trying to connect - this indicates that the network connection was **not successful**
{% endhint %}

{% hint style="danger" %}
If **NO LED** light is seen: open the sensor unit (see below) and check the batteries
{% endhint %}

<figure><img src="/files/lMUawLxpRYR5rb1xcFyI" alt=""><figcaption></figcaption></figure>

### Opening the R3 LTE Sensor Enclosure

* Remove the **four M4 machine screws** (#1 Philips) that secure the enclosure lid to the base
* If a battery clip is fitted - remove this by releasing the sides of the clip with a flat screwdriver
* Carefully seperate the lid from the base

{% hint style="warning" %}
**Take care when lifting the lid** - as the internal **antenna** is attached to the underside of the enclosure lid. Do not pull or twist the antenna cable.
{% endhint %}

* **Turn the unit off** using the slide switch&#x20;
* **Remove one** of the **batteries for 1 minute** - to perform a hard reset on the sensor unit
* If possible, check the battery **cell voltage** with a **multimeter**. It should be **above 1.2V** &#x20;
* Return the battery (if good) and turn the unit **ON**. Press the **READ** button under the unit

<figure><img src="/files/5Fmgrr4nZDiktZzM4B1B" alt=""><figcaption></figcaption></figure>