English XCVario user manual
Series 2020-2022

Software Version: 22.0

































Manual edition 2.46




Other versions of earlier software statuses at:



1. Description9

2. Features11

3. Overview12

4. Operation13

5. Device Management14

5.1. Reset/Debug14

5.2. Configuration Backup/Restore14

6. Airliner-Style Display15

6.1. Variometer15

6.2. Meam Climb15

6.3. Speed to Fly16

6.4. Altimeter16

6.5. Flaps recommendation16

6.6. Battery Indicator16

6.7. Temperature16

6.8. MC-Wert17

6.9. Wireless Symbol17

6.10. CAN Symbol17

7. Pointer Display18

8. FLARM20

9. Configurations and Router21

9.1. XCVario, Wireless Navi and FLARM22

9.2. XCVario, wired Navi (Kobo, OpenVario, IPX,. etc) and FLARM23

9.3. Two XCVario, two Wireless Navis and FLARM24

9.3.1. Front device24

9.3.2. Secondary device24

9.4. Two XCVario, two wired Navis (OV, Kobo, etc) and FLARM25

9.4.1. Front device25

9.4.2. Secondary device25

9.5. Two XCVario wireless, two wireless Navis and FLARM26

9.5.1. Front device26

9.5.2. Secondary device26

10. Setup27

10.1. MC27

10.2. Audio Volume27

10.3. QNH Setup27

10.4. Ballast27

10.5. Bugs28

10.6. Airfield Elevation28

10.7. Vario and Speed 2 Fly29

10.7.1. Range29

10.7.2. Log-Scale29

10.7.3. ​​ Mode29

10.7.4. Netto Mode29

10.7.5. Polar Sink30

10.7.6. Needle Color30

10.7.7. ​​ Center Aid30

10.7.8. Vario Damping30

10.7.9. ​​ Averager31

10.7.10. ​​ Mean Climb31

Minimum climb31



10.7.11. S2F Settings32



S2F Mode32

S2F AutoSpeed33

S2F Flap Pos33

S2F AHRS Deg33


Arrow Color34

10.7.12. Electronic Compensation34



10.8. Audio35

10.8.1. ​​ Default Volume35

10.8.2. ​​ Max Volume35

10.8.3. ​​ Cruise Audio35

10.8.4. Tone Styles35



Dual Tone36

Dual Tone Pitch36


Chopping Style36

10.8.5. ​​ Range36

10.8.6. ​​ Deadbands37

10.8.7. Audio Exponent37

10.8.8. Amplifier Off37

10.8.9. Audio in Setup38

10.8.10. Frequency Response38

10.8.11. Split Volume38

10.9. Weight/Polar39

10.9.1. Glider Type39

10.9.2. Polar Adjust39


[Speed 1]39

[Sink 1]39

[Speed 2]39

[Sink 2]39

[Speed 3]39

[Sink 3]39

10.9.3. Max Ballast40

10.9.4. Wing Area40

10.9.5. Empty Weight40

10.9.6. Crew Weight40

10.10. Options41

10.10.1. Student Mode41

10.10.2. Flap (WK) Indicator41

Flap Indicator41

Max postitive Flap42

Max negative Flap42

Takeoff Flap42

Flap Speeds Setup42

Speed +3 to +242

Speed +2 to +142

Speed +1 to 042

Speed 0 to -142

Speed -1 to -242

Speed -2 to -342

Flap Position Labels43

Flap Label +3:43


Flap Label +2:43


Flap Label +1:43


Flap Label 0:43


Flap Label -1:43


Flap Label -2:43


Flap Label -3:43


Flap Sensor43

Sensor Calibration44

10.10.3. Units45






10.10.4. [Airspeed Mode]45

10.10.5. Auto Transition46

10.10.6. Transition Altitude46

10.10.7. FLARM47

Alarm Level47

Alarm Volume47

FLARM Simulation47

10.10.8. Compass/Wind48


Sensor Option48

Sensor Calibration49

Setup Declination50


Setup Deviations50

Show Deviations51

Reset Deviations51

Setup NMEA51

Magnetic Heading51

True Heading51


I2C Clock52

Show Settings52

Wind Calculation53


Arrow Ref54

Straight Wind54


Airspeed Lowpass54

Deviation Lowpass54

GPS Lowpass54



Deviation Limit55

Sideslip Limit55

Course Limit55

AS Delta Limit55

Straight Wind Status56

Circling Wind56

Circling Wind Status56

Max Angle Delta57


Wind Logging57

10.10.9. Wireless58



Wireless LAN58

Wireless Client58

WL Routing58





WiFi Power59

Lock Master59


10.10.10. G-Load Display61

Activation Mode61

Positive Threshold61

Negative Threshold61

Red positive Limit61

Yellow positive Limit61

Red negative Limit.62

Yellow negative Limit62

Max Positive62

Max Negative62

G-Load reset62

10.11. System63

10.11.1. Software Update63

Software Vers.63

Software Update63

10.11.2. ​​ Factory Reset65

10.11.3. ​​ Battery Setup65

Battery Low65

Battery Red65

Battery Yellow65

Battery Full65

Battery Display65

10.11.4. ​​ Hardware Setup66


HW Type66


Color Variant66


Rotary Setup67




Setup Activation67


S2F Switch68

Gear Warning68

AHRS Setup69

AHRS Option69

AHRS Autzero69

AHRS License Key69

AHRS Gyro71

AHRS RPYL Sentence71

AS Sensor type71

10.11.5. ​​ Factory Voltmeter Adj72

10.11.6. Altimeter, Airspeed72

Altimeter Source72

AS Calibration72

AutoZero AS Sensor72

Alt. Quantization73

Stall Warning73

Stall Warning73

Stall Speed73

Maximum Speed73

10.11.7. RS232 Interface S174


Serial Loops74

S1 Routing74





TX Inversion75

RX Inversion76

Twist RX/TX Pins76

TX Line77

10.11.8. RS232 Interface S278


S2 Routing78





TX Inversion79

RX Inversion79

Twist RX/TX Pins79

TX Line79

10.11.9. CAN Interface80


CAN Routing80






10.11.10. NMEA Protokoll81






11. XCSoar84

11.1. ​​ XCSoar Konfiguration84

11.1.1. Bluetooth84

11.1.2. Wireless LAN85

XCVario TCP Ports85

11.1.3. ​​ Device driver86





XCVario commands:87

12. Installation88

12.1. Rear panel connections, 2020 series88

12.2. Connections rear panel, series 21&2289

12.3. Installation and drilling plan90

12.3.1. Drawing of the front part91

12.4. Micro USB92

12.5. Audio Ausgang92

12.6. Electrical connections93

12.6.1. RJ45 connector S193

Temperature sensor:93

Speed to Fly switch:94


12.6.2. RJ45 connector S295

Flap sensor96

12.6.3. Stefly OpenVario97

12.6.4. KRT2 Radio99

12.6.5. Temperature sensor99

12.6.6. Stromversorgung100

12.6.7. Vario / Speed to Fly Switch100

12.6.8. RS232 Interface100

12.7. ​​ Comparison IGC- and FCC Standard101

13. Technical specifications103

14. Maintenance104

15. Warranty Policy104

16. Permit105

17. Limitation of Liability106

18. CE Declaration of Conformity107

19. Appendix108

19.1. Sink rate depending on the load multiple108





The XCVario is a modern digital and smart variometer with wired serial and wireless interfaces to any navigation display or with applications such as XCSoar, LK8000 and more, as well as wired interfaces to a GPS source, a FLARM, an OpenVario or other devices. It has modern, high-resolution digital sensors for pressure, acceleration and temperature, an expansion tank as is usual with older systems is no longer required.

The XCVario is connected to the TE nozzle pressure, the static and the dynamic pressure, and compensated either conventionally via the TE nozzle or electronically. It has an audio function via its own built-in 2 watt speaker.


The forward-thinking Kalman filter offers a quick response to changes with good smoothing of the vario display, without the usual delay of a few seconds, which is known from simple damping. The Vario shows exactly what you feel. The Vario can also be adjusted according to personal preferences via the setup with many setting options.

From the 2021 series, the load multiple (n) is taken into account when calculating the current sink value from the polar coefficient using an acceleration sensor, because the increased load multiple requires more lift from the profile with the same aircraft mass (difference to higher ballast). This increases the drag coefficient and this leads to increased sink rates. In a standard class aircraft, for example, with a load multiple of 2 g, this results in about twice the sink rate. This is not insignificant and is taken into account in the net vario, which significantly improves the net vario display, especially in the case of dynamic processes (pull up, push down) compared to conventional devices without the corresponding sensors.


Optionally, a FLARM or another source for NMEA (GPS) data can be connected to the XCVario, the Vario not only forwards this data to XCSoar, tasks can also be declared on an (IGC) FLARM with XCSoar, settings made and the flight can then be read out. Clubs can operate the device with its many options in the "Hourless Mode", which allows users to only modify the 5 most important settings such as QNH, MC, etc.


The standard installed and freely available software of the XCVario (https://github.com/iltis42/XCVario) offers many features. In addition to a vario display, speed with MacCready setting, there is a precise altimeter, a wind indicator, a charge level indicator for the battery, a temperature indicator and more. The flap display, which can be switched on as an option, can display the flap position using an external sensor and provides information on the optimal flap position depending on the wing loading, the speed and the load factor. Thanks to a growing library of more than 100 polars for a wide variety of glider types, the vario can be adapted to almost any glider. Since the software is publicly available on github, developers can clone the software and further develop their own features and ideas, and also deliver them.


In addition to the independent function, the Vario can exchange data with the software running there via the wireless interface either via Bluetooth or wireless LAN (WLAN, Wifi), or via the RS232 (-TTL) interface, depending on which interface the device used has . The wireless standards ensure secure and stable transmission and have the advantage that there is no need for hardware-related and sometimes complex cabling with the navigation device.

Thanks to the high resolution of the digital, temperature-compensated and factory-calibrated pressure sensors, even the smallest height differences of just 8 cm are detected. Properties such as accuracy, reliability and long-term stability are therefore given. The sensor for the dynamic pressure or speed or IAS enables an absolute accuracy of better than 1%, at 100 km/h the deviation is a maximum of 1 km/h.
The outside temperature can be measured with the digital temperature sensor in the ventilation area to 0.5° Celsius with a resolution of 0.1° Celsius, and is included in the calculation of the TAS (True Airspeed) as an atmospheric parameter for determining the air density.


The exact flight speed, as well as the temperature and TE vario values, can be used to calculate precise values ​​for the target flight. The precise altimeter without hysteresis allows final approach altitudes to be calculated appropriately in XCSoar, because the wind calculation in XCSoar and now also in the XCVario itself works reliably and precisely together with a GPS source.

It is very easy to operate and is done using the rotary (rotary knob) with Push&Turn (press and turn), next to it there is a button to switch it on.

The system, which is manufactured in large numbers, is an excellent replacement for old vario systems with many additional modern features.


  • Airliner-style bar display or retro-style pointer display

  • TE variometer with optimized Kalman filter, adjustable range and damping

  • Barometric altimeter with QNH setting or QNH autosetup (airfield altitude as default)

  • Speed display (IAS or TAS) with speed command (S2F)

  • Adjustable wing loading and MacCready value

  • Built-in speaker with volume control, power 1.2 watts

  • Sound individually configurable (height, chopping, dual tone, deadband)

  • Flaps display with optimal position according to ballast, airspeed and the load factor

  • Extensive polar library with over 100 common polars

  • Polar can be modified later

  • Digital compass with external magnetic sensor (21 series)

  • Wind calculation in circular flight and with compass also straight flight (TAWK method, in development)

  • MacCready, ballast and bugs setting option

  • stall warning

  • Outside temperature display with external sensor

  • Battery charge status display, voltages configurable

  • Wireless Bluetooth V4.2 (classic BT) or standard WLAN access point for external devices

  • 2x RS232 TTL interfaces, S1 with standard cable in IGC standard, S2 socket in IGC standard

  • High accuracy barometric altimeter

  • Sunlight readable, bright and high-contrast 2.4 inch IPS display with 57 mm diagonal

  • Switch input for vario/set speed changeover (switch or button adjustable)

  • Simple setup menu using rotary switch with push and turn function

  • Light and small device for standard 57 mm instrument cut-outs, housing depth only 35 mm

  • Elegant and robust CNC milled matt black anodized aluminum housing (shielding, low EMI)

  • Software update via Wifi 'Over The Air' (OTA) when installed for new features

  • Analog input for flap display

  • As an alternative to the flap display, landing gear warning via the same input

  • Full FLARM Bridge for task declaration in IGC Flarm, flight download and FLARM setup


From the 2021 series, the following 3 new hardware features will be added:


  • Second serial RS232 TTL interface S2, IGC standard assignment and DTE and DCE support (RX/TX pins exchangeable via software)

  • Audio power now 2 watts, better sound at high volumes

  • Input e.g. for a flap sensor or an undercarriage warning

  • Optional feature: Attitude and Heading Reference System (AHRS): 6-axis direction and attitude sensor with 3-axis gyroscope and 3-axis accelerometer


From series 2022:

  • In addition, a CAN bus interface on S2 for connecting a second two-seater device, a CAN magnet sensor (from October 2022), as well as future extensions.



The following overview shows the embedding of the XCVario in the cockpit environment.

The standard case and most common case is the connection of an Android device with XCSoar to the wireless interface with Bluetooth, as well as a FLARM with the appropriate cable to interface S1. For this purpose, the interface S1 is connected to the wireless interface. This is the delivery state of the settings.

With the Wifi standard on the wireless interface, it is also possible with devices from the 2021 series to control another device, e.g. a radio device on the S2 interface. More on this in the XCSoar Setup chapter.


The operation of the XCVario is very simple and intuitive, and takes place via a rotary knob (rotary) with button function (push and turn), an optional additional switch or button (configurable) for Vario or speed command mode, and via the on-off switch. The following description applies to the default setting, the function of the rotary can be set, more on this in the chapter on setup.

After switching on on the ground, the QNH must first be set on the rotary knob, or confirmed if the elevation (height of the airfield) is configured. After pressing the rotary knob, the display and the data transmission of the device go into operation. Turning it to the left decreases the volume, while turning it to the right increases it.

During operation, the menu for the parameters such as MC value, ballast, polar and more is started after pressing a button (push).

A simple push takes you to the top point of the setup [<<Setup], which offers a return from the setup without turning, i.e. scrolling in the menu. Another push without scrolling switches back and forth between setup and normal operation. In the setup menu there is a help text for almost all functions so that the correct settings can be found quickly even with little practice.
By turning the rotary to the right, corresponding to "scroll down", or to the left for "scroll up", the individual sub-items are selected in the setup.

Most of the items in the setup menu return to the top item of the previous level, allowing multiple settings to be made without exiting the menu entirely.

The setup menu is nested, you can descend further into the individual items by pressing a button (push), the top item returns to the previous menu.
All setting values can be decreased by turning to the left and increased by turning to the right.
If you want to save the value, you can acknowledge this with a simple push, the saving is confirmed and you return from the dialog.
Dialogs for parameters that are usually set separately, such as the MC value, return directly to the vario display. This saves you having to press another button to exit the setup.

The XCVario can also be remotely controlled via software commands, supported is rotary operation such as short or long press to change the screen, for example, or to go to the setup, scrolling (up/down) for the menu navigation, as well as some shortcuts for Changes in volume or MacCready value.