# Operating Procedure | Flying and Monitoring the Tethered ALTA X ## Monitoring the LCD on the Tether Ground Station The **EON800 Tether System** is designed to supply continuous power and communication to the **ALTA X**. The *LCD Screen* on the **Tether Ground Station (TGS)** monitors *ALTA X MAVLink* data, identifies in-flight errors, and warnings, and provides actionable guidance to the user. {% hint style="danger" %} Autoland Battery Failsafe is not automatically setup on the ALTA X. Please refer to the [Autoland Battery Failsafe and Geofence](https://xm2labs.gitbook.io/eon800-user-guide/freefly-altax-tether-eon800-xm2/reference/autoland-geofence-altax-failsafe) section of this manual and the [Procedures section of the Freefly Systems ALTA X Manual](https://freefly.gitbook.io/freefly-public/products/alta-x/untitled-6) for more information on setting up this Freefly Systems feature. {% endhint %} ## LCD Screen Pages ### Tether System Data Page Toggling ON the **TGS** *High Voltage (HV) Missile-Switch* will automatically trigger the *Tether System Data Page* on the *LCD screen*. At the top of the *Tether System Data Page*, a timer is included to display the duration of high voltage activity (flight time). Four quadrants, known as *Data Cells*, divide the *Tether System Data Page*.

Tether System Data Page (Fig.1)

Each *Data Cell* highlights the cell name, the data value, a bar graph, and a continuously updated *exception value*. The top corner of the *Data Cell* displays the *exception value*, indicating the most critical value recorded during the last 3 minutes of operation. Alternatively, the *exception value* in the *Altitude Data Cell* indicates the real-time m/s velocity change. For Example, the *Data Cells* on the *Tether System Data Page* above (Fig.1) displays the following parameters: 1. **Current**: The APU is drawing 61.3 Amps, with the highest draw in the last 3 minutes reaching 62.9 Amps. 2. **Voltage**: The APU output voltage is 48.6V, with the lowest output voltage in the last 3 minutes being 48.0V. 3. **Temp**: The APU's current temperature is 45°C, with the highest recorded temperature in the last three minutes also at 45°C. 4. **Altitude**: The aircraft is at a height of 80m, maintaining a constant velocity of 0.0 m/s as the ALTA X hovers in place. {% hint style="info" %} The *Exception Value* is displayed in the bar graph, with its visualisation and marking reflecting its severity. Most data shown on the Tether System Data Page is sourced from the Air Power Unit (APU). Colour coding is used to signify the status: * **GREEN** denotes a value well within the system's operating range. * **ORANGE** indicates the value is nearing the system's operating limits. * **RED** signifies a value outside the operating range of the system. {% endhint %} #### Current Data Cell The *Current Data Cell* displays the **APU** current draw in Amps. Ensure the **EON800 Tether System** current draw stays below 95A continuous. The **APU** consistently supplies the final power to the **ALTA X** from the tether system, also integrating the *Backup Battery Function*. \ \ The most critical data point is the current draw. An *LCD* [*Warning Message*](#warning-message) will alert the operator if the tether system continuously draws over 95 Amps for 3 seconds. The bar graph presents the current draw as a percentage of the maximum output (100 Amps), while the *exception value* shows the highest instantaneous current draw in the last 3 minutes of operation. #### Voltage Data Cell The **Voltage Data Cell** shows the **APU** current low-side output voltage to the aircraft. This voltage also represents the backup battery voltage. Typically, the voltage output ranges between 47.0V and 50.0V, and an *LCD* [*Warning Message*](#warning-message) is triggered if voltage drops below 46.5V for over 5 seconds. The bar graph illustrates voltage as a percentage from 40.0V to 52.0V, while the *exception value* displays the lowest recorded voltage over the last 3 minutes. Excessive current draw is the primary cause for low output voltage. The **TGS** automatically reduces output voltage to prevent system failure. #### Temp Data Cell The **Temp (temperature) Data Cell** reads the temperature of critical APU components. XM2 recommends maintaining an **APU** temperature of 10-20°C (50-68°F) above the ambient air temperature. An LCD [*Warning Message*](#warning-message) is triggered if the APU temperature exceeds 90°C (194°F). If the temperature goes beyond 110°C (230 °F), the **APU** will shut down and the **EON800 Tether System** will no longer be powering the aircraft. Operating near maximum power, high outdoor temperature, and positioning against strong winds can elevate **APU** temperature, reducing internal heat sink airflow. If a temperature [*Warning Message*](#warning-message) appears on the *LCD*, follow the instructions on the screen. An example prompt to lower the APU temperature would be to yaw the aircraft and direct the nose of the **ALTA X** into the wind. \ The bar graph illustrates the current temperature as a percentage of the maximum advised temperature of 90°C (194°F), with the *exception value* indicating the highest temperature within the last 3 minutes. #### **Altitude Data Cell** The *Altitude Data Cell* displays the current aircraft altitude, measured from the takeoff point to the aircraft's height. Altitude value must not exceed the maximum permitted altitude based on the operator's configured tether length. The bar graph represents the current flight altitude as a percentage of the maximum allowed height for the tether system. The *exception value* in the *Altitude Data Cell* displays the real-time meters per second of velocity change. ### Simplified In-Flight Data Page The Simplified In-Flight Data Page displays the current flight time (HV is switched ON) and the current altitude of the Aircraft. The *LCD* will automatically display any [*Warning Messages*](#warning-message) or [*Critical Error Messages*](#critical-error-message). ### Battery Cell Data Page During tethered flight, the **Battery Cell Data Page** shows individual cell voltages, indicating backup battery health monitored by the **APU**'s *Battery Management System* (*BMS*). The **APU** is equipped with a built-in **BMS** to monitor and manage the backup batteries. The *BMS* aims to control the battery's environment, balances the battery cells, and protect them from operating outside of their specifications. The graphs on the **Battery Cell Data Page** illustrate the voltage of each individual cell as a percentage, ranging between 3.2V and 4.3V. If any cell falls below 3.4V or exhibits a significant voltage imbalance of 150mV, the operator will receive a [*Warning Message*](#warning-message) to land the aircraft. This warning indicates a potential battery cell issue. In the event of a critical error with the tether system, a significant issue with the battery cells may affect your ability to emergency and using **Backup Batteries**. If you receive a [*Warning Message*](#warning-message) about the battery cells, it's crucial to check battery health and replace them if necessary. ### Logging Data Page The **Logging Data Page** displays onboard log data on the ***SD card*** (FAT32 format) including: file name, current log size, available space, and total capacity. The tether system will automatically remove any old telemetry log files and make space for new ones. This eliminates the need for the user to delete files on the **SD card** as it fills up. ## LCD Screen Messages #### Warning Message If a *Warning Message* appears on the *LCD*, follow the instructions provided. After addressing the issue, such as lowering the aircraft to reduce the load, press the middle button below the *LCD* for three seconds and clear the *Warning Message* to resume operation. #### Critical Error Message If you experience a *Critical Error Message* during operation, the **TGS** will alert you with a beeper, the *LCD beacon* will flash red and green, and the *LCD* will provide guidance on the necessary steps to take. {% hint style="danger" %} Autoland Battery Failsafe is not automatically setup on the ALTA X. Please refer to the [Autoland Battery Failsafe and Geofence](https://xm2labs.gitbook.io/eon800-user-guide/freefly-altax-tether-eon800-xm2/reference/autoland-geofence-altax-failsafe) section of this manual and the [Procedures section of the Freefly Systems ALTA X Manual](https://freefly.gitbook.io/freefly-public/products/alta-x/untitled-6) for more information on setting up this Freefly Systems feature. {% endhint %}