Frequently Asked Questions

External Devices

  • In addition to an serial Navi (XCTouchNav, OV), can i connect also the magnetic sensor to S2?

    From XCVario series 22 onwards this is possible via the S2 Splitter that opens the possibility to connect a device to the CAN bus and also to the serial interface. Also a Flap sensor can be added to the S2 Port Extender Splitter .

  • Can I control the vario/target travel switchover using a remote stick?

    A vario/target travel switch is a useful addition. 

    Although in the default setting “AutoSpeed” the S2F mode can also be switched automatically from a certain speed, or in one of the other modes, for example via a flap sensor or via the gyro (circle flight), pilots often like to use this mode determine yourself, which is why a target travel switch definitely makes sense. 

    Most remote sticks or control sticks therefore also have their own switch, or rather a button, with which you can switch the mode. The target travel mode is automatically transmitted from the XCVario to the navigation system via the NMEA protocol. To do this, connect the switch/button of the remote stick to the two S2F-labeled ends of the cable supplied with the XCVario and, if necessary, change the “S2F Switch” to “Push Button” in the hardware setup if it is a button. Two buttons can also be used in double-seaters. Both buttons are connected in parallel to the front device and the “External” mode is selected for the “S2F Mode” of the rear device.

    Theoretically there is also a way to transfer the S2F status from the navigation system to the XCVario via NMEA. This would also be supported by the XCRemote/blob/main/minimal.xci ), which redefines the buttons on the stick's panel (does not work with the small front button intended for S2F), and thus sends NMEA messages to the Vario to allow S2F to toggle. However, I advise against it because the NMEA protocols were not intended that way, Vario/setpoint travel should always come from the Vario, the .xpi events in XCSoar are only documented as source code, the process is complicated, uses a button on the stick, and the Stick doesn't really reflect the internal status in XCSoar. This only works correctly to a limited extent, the states can easily diverge and this would require an additional state (variable) in the xpi parser, i.e. a source change in the XCSoar that is currently not available. Therefore the recommendation is to use the variant in the above section and connect the S2F switch to the Vario cable.

  • Can I connect a navigation system (older Oudie, Kobo, etc) via the serial interface?

    Yes, you can do this. In order to go for that, check if “XCVario” in the routing for the corresponding serial interface is 'Enable', the data will then be routed there. The correct baud rate is also important. If you look at what's coming in via the data monitor in your Navi app, and you see illegible characters - it's usually just the baud rate that's wrong there.

  • I have assigned both interfaces, how can I also control a radio device?

    There is nothing wrong with creating another Bluetooth connection in the XCSoar device manager alongside the XCVario for this purpose. An inexpensive device for this is available in the shop (, and there are other bridge solutions from other manufacturers on the market.  

  • Is there a Larus Breeze display in the XCVario?

    A display driver for the Larus-Breeze in the XCVario does not exist and is not created by the XCVario side. Nothing speaks against corresponding supplies from the Larus project. Currently, Larus information can only be displayed in the XCSoar project's own 'OpenVario' fork. A driver for this in XCSoar, LK8000, XCVario or other open source projects does not yet exist.

  • SeeYou Navigator and XCVario or XCTouchNav

    The SeeYou Navigator currently does not support a variometer, so it cannot use the data from the XCVario, even if it were connected. 

    Furthermore, SeeYou cannot work with any other BT devices, except with the BLE dongle that Naviter sells itself. Other BT classic or BLE sources are not accepted by Naviter SeeYou and are blocked within their SeeYou software (connection will fail).

    Please contact Naviter regarding this issue. SeeYou Navigator plans to be more open in the future. Unfortunately we cannot help here, the problem is not on our side nor on our Android devices, this does not currently work on any Android devices on the market.

GPS Source & Flarm

  • When i send a task from XCSoar to Flarm an error occurs and is Task not declated

    The problem mostly comes from mutiple devices connected to one Flarm port. In principle, only one device can be connected to one serial interface port, and flarm manuals will say exactly this, just _one_ device.  

    Golden Rule: As long as you follow this guide, RX and TX is wired between XCSoar and Flarm, and nowhere else, all is good, and you can declare tasks.

    This limitation coming from the RS232 protocol that is a pure peer to peer protocol. The good news, there are tricks to connect multiple devices to one RS232 port, e.g. the second device does not have wired the transmission direction (TX) towards its peer, it can be connected in parallel. Analogy: One teacher can talk to multiple students at the same time, but only one student may as a question. To get this run it may require special cables or adapters which not all have connections and do not connect the TX wire from all other peers, except XCSoar. There is no issue with the XCFlarmView's 1.4 and 2.4 inch, with recent SW loaded they can be connected in parallel and SW download is possible, those products do not use their TX line and are only listening. 

    Hence there is also bad news as this does not work with any peers, several gadges require a bidirectional (RX/TX) connection e.g. some gadgets try to do baudrate negotiations at startup with the Flarm and once they can't sent there, this will fail, it will not be usable. Some have lifted that with a switch in the TX line, and disconnect those gadgets from Flarm when flight download shall occur. 

  • How to setup compass for best accuracy?

    The following things can play a role in an incorrect display of the cardinal directions.

    1. First you have to check whether the magnetic sensor is set correctly . There are two types, the I2C sensor and the CAN bus sensor. If the length of the board is more than 30mm , then it is the CAN bus type, which will be supported from series 2022 and can be set in the Compass Menu in the “Senor Option” with “Enable CAN sensor”. Otherwise it is the I2C sensor. For the CAN sensor, also the data rate must also be set to 1000 kbit in the “CAN Interface” menu.
    2. Next, if this has not already been done, the sensor needs to be calibrated . This requires a bit of skill and should be done in an area free of magnetic interference. A video with corresponding explanations is here. The calibration can also be viewed under “Show” in the “Sensor Calibration” menu. If the “Scale” values ​​differ by more than 10%, there may be a hardware error. If necessary, repeat the calibration in another location, typically the values ​​are between 95 and 105.
    3. Whether the transmission to the sensor is working well can be viewed in the “Sensor Calibration” menu under “Show Raw Data”. The digital values ​​of the Hall sensors for the 3 directions X,Y,Z are output. These should have maximum values ​​of around +- 7000. The sensitivity of the current sensor chips is 14000 per Gauss for the current and smaller sensor chip (1.2×1.2 mm), and 12000 per Gauss for the older one until around mid-2022 (3×3 mm). Gauss. The earth’s magnetic field in Germany currently has a value of 0.45 Gauss, maximum values ​​of almost 7000 or 6000 are to be expected. For the individual directions parallel to the earth’s magnetic vector, this -+ 10% should be displayed (rotate the sensor as during calibration), and there should be a maximum of -+50 noise, significantly less in an EMC-free environment. If nothing is displayed here, or the values ​​are very wrong or are not rewritten several times in a second, check the settings and the cabling, there may be a hardware problem with the sensor.
    4. If the compass does not display any meaningful values ​​despite the above measures, the tilt compensation could be playing a trick. First check whether the sensor is in the same plane as the variometer. If you are testing on a table, it is best to place the variometer on a flat surface and move the sensor exactly horizontally. Small deviations can cause large errors at an inclination of 70° (Central Europe, D). Even an inclination of 20° can distort the heading to the opposite course. The tilt angle compensation works correctly if the device completes the AHRS test with OK when switched on and the gravity is displayed as (1.00 g) +- 0.01. In the case of larger deviations, carry out the AHRS calibration in the hardware setup as described in the manual. Recent software requires a flat horizontal surface (e.g. apron), to align the sensor to your gliders axes. At home you may reset an incorrect AHRS calibraton while the gadget resides on a horizontal aligned surface. 
    5. If values ​​of +-10 are now measured in all directions, the compass is OK, the remaining errors are now due to deviations caused by magnetic interference fields. Now you can either activate the autodeviation in the compass menu, which takes a few flight hours to automatically determine the deviation at the installation location using the wind calculated in a circular flight, or you can place the plane on a compensation site with floor markings and carry out the compensation every 45° described in the manual. With successful compensation, accuracies of 1-2 degrees and better can be achieved.
  • How to troubleshoot if Flarm data is not arriving?

    If the monitor in the navigation system shows neither “FLARM” nor “GPS”, the error can be localized and corrected using the following methods. As a rule, the Flarm is connected to the XCVario S1 Flarm cable. 

    1. First check whether the Flarm data arrives in the XCVario. To do this, select “ Monitor ” under Options/Wireless and check the corresponding interface. Normally the Flarm is connected to the connector on the wiring harness labeled “FLARM”, in this case select RS232-S1 and check the data stream.
    2. If no data comes at all (black screen, RX and TX counters show 0), then check the settings. For an IGC compatible Flarm without changing its settings, the settings as set at delivery are usually necessary. In particular: Twist RX/TX: Normal is relevant here. If this is set to “Twisted”, communication with the Flarm does not work and the RX/TX pairing does not fit on the interface. TX,RX Inversion : Inverted must also be set on an IGC compatible Flarm. IGC compatible Flarm’s send their data in RS232 TTL format, and this delivers signals that are inverted compared to the RS232 standard.
    3. Otherwise, check on the Flarm page, for example in the settings, whether the GPS and Flarm data are also being sent out, i.e. whether the GPS has synchronized and the status of the device is OK, and no setting prevents the GPS data or Flarm data from being sent out . To do this, check whether the checkbox for “ Navigation ” is checked when configuring the Flarm , or in the FLARMCFG file, if the configuration is done via file, the configuration record for sending the NMEA data is also set to 1 , exactly: “$PFLAC “S, NMEAOUT,1 ” would be correct.
    4. A cable problem is also conceivable, plug in the Flarm directly to test (without any extension), if necessary also check the cable, the relevant connections are GND, RS232-RX and -TX, see the manual for the corresponding interface. A defect in the Flarm/GPS is also possible, but the latter is very rare.
    5. If the monitor shows unreadable data, an incorrect baud rate may be the case. Unless the Flarm has set a higher baud rate, the default setting is 19200 baud . Otherwise, match the baud rate of the two devices. If the baud rate is incorrect, only a few readable ASCII characters can normally be recognized and predominantly only squares with diagonals are shown.
    6. The signal polarity on each pin can also be adjusted, "TX and RX inversion"must be set to "Inverted" for IGC compatible Flarms. An incorrect setting at this point can result in the receipt of illegible characters (displayed as a square with diagonals). In this case, you can usually see some related letters, numbers or special characters in between, such as 33d4g and the like.
    7. If the serial setup is correct, the GPS data sets can be recognized like a $GPRMC, and the Flarm $PFLAU, etc. The field after the second comma in $GPRMC is the “position status” (A = data valid, V = data invalid), and shows whether a valid GPS fix is ​​available. This is the case in the example in picture from last sentence. $PXCV records should not appear. In this case, set the "XCVario" to "Disable" in “S1 Routing” . The Flarm itself doesn’t do anything with the variometer data; on the contrary, in the worst case, this can also throw the Flarm out of step.
    8. If the data arrives in the XCVario, but not in the If the navigation system, check if the data from Flarm, usually from S1-RS232, is routed to there. To do so check the routing on that interface where your Navi is connected, for a wireless Navi this is the "S1-RS232" that is to be set to "Enable" under "Wireless" -> "Routing". The same applies if the navigation system is connected serially to S2 , then the "RS232-S1" must be set to "Enable" in the routing of S2 so that the Flarm data is forwarded to S2.
  • What to do if the Navi doesn’t show an airplane symbol and/or GPS not connected?

    There are several things to check when GPS show not connected on your Navi:

    • First check whether the transmission to the GPS source, usually a Flarm, looks good. If this is not the case, check under “My Flarm data is not arriving” why the data is not arriving. 
    • Then it depends on exactly which error is displayed. If “GPS is not connected”, it is possible that the device source in the navigation system is switched off or that the source does not provide any data (as mentioned above). 
    • If “GPS is waiting for position determination” and only “FLARM” is shown, the GPS may not have loaded the almanac yet and still needs time to synchronize. FLARM and GPS are two different hardware modules, one may work, the other may not. 
    • For further diagnosis, look at the $GPRMC data set that should come from Flarm. Maybe only “Navigation” is switched off in the Flarm Settings. If the Flarm has several ports, it is also possible that another device, for example a butterfly display, limits the transmission of GPS data to only the port where it is connected. 
    • If the $GPRMC does not arrive even though navigation is switched on, the GPS module could have a defect. In this case, check the Flarm, first whether the GPS lamp turns green permanently and then check whether the $GPRMC arrives in the device monitor of the navigation system and its status bit is transmitted with “V” i.e. Valid. Format see link here: 
    • The following procedure if the above measures are unsuccessful: Create a loop on the S1 or S2 serial port from TX to RX and see if anything comes back. To do this, bridge pins 3 and 4 on the Flarm cable end or the cable in S2, e.g. with a Y-piece 8P8C (everything connected through) and a cut LAN cable with standard color assignment (as described in the manual). Connect blue and green white cables to the open end of the LAN cable and start Wireless->Monitor->S1-RS232 (or S2-RS232). With a little skill you can bridge pins 3,4, which are the third and fourth pins from the right (see manual), with a paper clip or with a thin wire (D < 0.3 mm). Whenever the pins are connected, RX should count up as everything that is sent should be then received back (RX = TX). If it doesn’t look like this , then there might be a problem in the hardware or the wiring harness. We did not have yet had a defect in the serial interface in the field. The wiring harness is available here , otherwise send it for repair .
    • RX/TX counter looks okay then XCVario including the cable is running without errors, and the error is in the Flarm or the connection to the Flarm and not in the XCVario. In this case, further determine the error in the direction of Flarm, e.g. connect another device such as a Flarm display to the same port on the Flarm and check that it works, otherwise contact the manufacturer of the Flarm.
  • My Flarm has a 6-pin RJ12 connector, how do I connect it?

    Either use an RJ45 coupling on the S1 Flarm cable end of our cable tree and a there the 1:1 standard RJ12 cable 6P6C with a suitable length in the middle, the one shipped with the Flarm or available from Amazon, eBay (look for RJ12 6P6C), and insert this cable in the middle of 8 pin the RJ45 interface connector. The Flarm in that case will have its own power wires (never powered trough 6pin RJ12 cable). 


  • I get some radio interference with the XCVario

    Normally there is no issue with radio interferrence from current XCVario series, exect a handful of XCVario-20 series, all further device have carefully been designed with the result of very low electro magnetic noise in the radio band. As of that there are a very low number of reports from field where oder gliders or installation’s are affected by radio interference on some frequencies. The good news: Any of those issues could be traced down to issues on glider side coming from the antenna shield at the radio antanna connector. The shield of the coaxial cable tends to break or slip out from the BNC connector over time, so there is no more (good) ground contact, and once the shield of the coax cable is defect of broken, there is an wide open door for any EMV noise that is amplified by the radio receiver, and power or digital signal cables from/to other gadgets close to the antenna will create issues. 

    Fixing the follwing things helped in that cases reported:

    1. Antenna insulation: Check and measure if the coax cable shield is connected to the BNC connector of your radio, and fix in case this is not well made, Tutorial's for different types of connectors below:
      1. Crimp type: 
      2. Solder type:
    2. Separate antenna cable from other, esp. from digital wires
    3. Do not place radio and digital gadgets close together. If possible separate radio and digital gadets by one mechanic instrument in between
  • How to deal with a display that shows a bright spot?

    Any LCD display can be damaged by the effects of heat, which can occur due to the burning glass effect when folding hoods open to the front and the sun is low. 

    This also applies to the display of the XCVario. Damage caused by external influences is not covered by the guarantee, but in this case XCVario will be happy to replace a defective display for a small flat rate of €49.

    Alternatively, glider pilots are usually very technically skilled and are therefore able to replace the display themselves. Replacement modules can be sent for the current price of €18. 

    Instructions are shown here. Flat-nose pliers, a 5mm bit and a Torx T10 screwdriver (possibly also a Phillips head) are all you need. An antistatic base, a wooden board, or chipboard is also an advantage. A wrist strap to dissipate static charge would be ideal, or keeping one arm in contact with the surface when touching the open device.

    1. Loosen the 4 screws on the back and remove the QC sticker. If the device is not further damaged during replacement and the device is still under warranty, other defective components will be repaired without the QC seal. After loosening the screws, remove the back. To do this, the device with the pneumatic connections can be easily pressed onto the table while holding the device to the side. The back should then come off. Now you can disconnect the speaker from the two-pin JST connector.
    2. Next, the four 5mm hex bolts are removed from the sensor board. Loosen the front bolts in the picture with the 5mm bit, the rear bolts next to the block for the pneumatics with the flat-nose pliers and unscrew them by hand. Keep the 4 bolts separately; these must be screwed back in at this point; the front bolts differ in their thread length.
    3. Pull off the rotary knob at the front (it’s not screwed, just pressed) and pull the sensor board backwards from the display. The display board is now exposed and the 4 hexagonal bolts can now all be unscrewed with the 5 bit. Lay these separately, have a shorter thread and must be screwed back in there.
    4. Then unlock the ZIF socket at the two movable latches on the left and right ends and pull out the display connector. The display PCB can now be removed from the front part and carefully detached from the PCB. There is double-sided adhesive tape on the sides so that the display stays in place without wobbling. The new display comes with a blue protective film on the adhesive strip. Remove this film and the new display can now be inserted into the front part. 
    5. Now place the display PCB on the front part and screw the hexagonal bolts back in. Insert the connector of the new display completely into the open ZIF socket (this can be done without force, ZIF = Zero Insertion Force), and carefully close the two locking latches with the flat-nose pliers. When correctly closed, no visible gaps will appear here . Make sure both sides are closed. When you press one side closed, the other side tends to open again; for example, hold it with your finger while the other hand carefully presses closed with the pliers. It is also possible to close the locking latch with your fingernail, but this requires some force.
    6. Reconnect the fully assembled display to the sensor PCB using the shorter hexagonal bolts, making sure that the circuit board connectors mesh correctly. This means reassembling in the reverse order. Tighten all hexagonal bolts very slightly and then put the rotary knob on and check that it moves smoothly. If it’s difficult to do and doesn’t come back when you press it, then loosen the bolts a little again and turn the button a few times, the shaft will then center itself, and then tighten the bolts without moving the PCBs against each other again. Finally, plug in the speaker and put the housing cover back on. Be careful not to pinch the speaker cable.


  • What can be wrong if speed to fly (S2F) does not fit to my expectation?

    The following points are to be checked if the S2F display does not appear correct. The S2F depends on the gliders performance polar, the current wing loading, the MC value setting and the load factor.

    1. Correct polar selected? To check this, open in the “Glider Details” setup whether the correct type is selected. The default “User Polar” corresponds to an LS4, for any other glider type this must be set to the appropriate pattern under “Glider Type”. Check the “polar points”, which are the sinking speeds for three speeds, with the flight handbook, they should match the values shown there. Polars always apply to a specific wing loading, this must also match from the polar in the manual.
    2. Wing area and empty weight correct? In addition to the aircraft type, the wing area and empty weight must also be checked. Aircraft types with clip-on ears can be flown in different configurations and therefore wing areas and empty weights. If there is a separate polar for each of these configurations, the correct polar must be set before starting. For example, the DG600 is available as DG600/15 and DG600/18. This adjusts the wing area and empty weight accordingly.
    3. Empty weight appropriate? Gliders have a tendency to become heavier over time. This is not only due to additional installations, paintwork and a humid environment with water absorption in the hygroscopic GRP/CFRP can also lead to a higher weight than was the case when flying the polar with the prototype. This can be adjusted using the last weighing report (weight and balance) under “Empty Weight” in the Glider Details, and affects wing loading such as additional ballast.
    4. Ballast correct? The setting for the ballast or amount of water filled, if the aircraft has a ballast tank, may differ from the actual weight. It may have been forgotten to set the water to zero when draining on the last flight, or the ballast was not set to the value that was actually refueled. Therefore, check the ballasting “Ballast” in the setup before each start.
    5. AHRS adjusted? The correct S2F depends not only on the wing load but also on the load factor. It is important to zero AHRS sensor as described in the Manual. The sensor should then show the value 1.00 g in the second line when switched on. If this is not the case on ground, S2F well be inaccurate or may overshoot during push/pull. Here an example (0.94 g) that shows a device where calibration is necessary. This has to be done once after installation.
  • The software update does not go through or does not update the software

    The following problems can occur when updating the SW via the Wifi (WLAN) access point: 

    • Incorrect file: It is possible that an attempt was made to load an incorrect or corrupt file. To rule out this, check the size of the file and, if in doubt, load it again. The file must have a .bin extension and a length of approximately 1,708,400 bytes (1.7 MB), check before downloading. 
    • Transmission errors: In combination with some devices, cell phones or laptops, as well as in the wireless LAN environment, it is possible that transmission errors occur; the new version is rejected and not activated so that the device remains operable. To remedy this, hold the device closer than 30cm to the Vario during the download. Maybe check whether there are WiFi networks nearby that may be on the same channel, if possible repeat the download outside of their range, or try another device. 
    • WLAN change: The device for the download spontaneously changes the WLAN network: Many Android devices spontaneously switch the network during the download. To do this, check whether the WLAN network remains on “ESP32 OTA” throughout the entire download. After establishing a connection, most Android devices need a confirmation to remain on the non-internet-enabled network, or they spontaneously switch to a different WLAN and the SW download is interrupted.
    • Mobile data: Several recent mobile phones have issues to route the IP traffic to a no internet capbable WiFi network (the ESP32 OTA), so switching OFF the mobile data when connecting to the ESP32 OTA Hotspot may solve this problem.  

  • After SW update my airspeed display remains at “0″

    When updating older devices in the field from older software versions, it may happen that the correct type of airspeed sensor is not yet known. To do this, check the type of sensor in the setup under System->Hardware
    Setup->AS Sensor Type. Only the MP5004 is detected automatically; the types APBMRR and TE4525 must be set manually. The problem can be solved using the following method:
    – If APBMRR is set, select the type TE4525
    – If TE4525 is set, select the type ABPMRR
    check, blow carefully into the pitot tube; the sensor that gives a positive display of the airspeed is correct he follows. The setting is retained even after a factory reset and must be made once.


  • What is the WiFi password for the XCVario?

    The WiFi password is: xcvario-21

  • Can I connect a Flarm display aside with XCVario to one single Flarm port?

    The manufacturers of Flarm devices limit the connection to just one device for good reason, but there is nothing wrong with two or more devices that only read from the serial interface and do not send anything to the Flarm. 

    Since displays sometimes also transmit (e.g. to self-discover the baud rate), you can shut down the TX line there (tweak or switch) if found, or switch off the TX line in the setup with the XCVario, but a flight download or a task declaration is not possible with this configuration.

  • Can I connect a push button for S2F instead of a target travel switch?

    Yes, it works, a push button is supported and must be configured accordingly in the S2F Settings -> S2F Switch -> "Push Button". The S2F (speed to fly) mode will toggle then by every press.

  • I have installed my switch the wrong way round. Can the S2F/vario mode be turned?

    Yes, to do this, select the “Switch Inverted” option in the setup under S2F Settings -> S2F Switch.

  • Can the XCVario be installed in an 80 mm cutout?

    The 57 mm device was designed and optimized for a 57 mm panel cut-out in order to take up as little space as possible, but it is possible with the matching adapter with M4 threads, which is available in the shop. The screws that hold the adapter must be shortened flush at the back so that the 57 mm XCVario also fits into an 80 mm cutout.

  • Can I connect the flap sensor and the magent sensor at the same time?

    Yes, it works, you need the S2 port splitter offered in the shop. The flap sensor and a CAN magnet sensor can be connected to the CAN port at the same time using the flexible 8P8C RJ45 1:1 network cables as provided with the extensions.

  • Can i pair multiple wireless devices with one XCVario?

    Yes that works, but only in WiFi mode. Up to three devices, e.g. a second XCVario (as a client) and two mobile devices can be paired with the XCVario.

    Using Bluetooh only one device can connect to XCVario.

  • How to fix a TEK compensation that does not work optimal?

    If the Vario deflects unusually when pulling up or pushing down, the following points should be checked for optimal TEK compensation:

    1. Incorrect hose connection: First check the hose connection for correctness. A common cause of errors is swapped hoses, for example if the hoses for the TE (nozzle) and ST (static pressure) are swapped. To check, blow very carefully into the slots or openings of the TEK nozzle. When the pressure increases, the Vario must fall; when it decreases (suction), it rises. Incorrect tubing typically produces very serious errors with readings of -+5 m/s and more.
    2. Leaky system: A leak in the system, for example due to defective O-rings on the TEK nozzle, leaky connections due to hardened or defective hoses, or even due to a defect in a device can occur. It is not for nothing that most glider and equipment manufacturers provide instructions for an annual leak test of the system. Using the display and bellows of a blood pressure monitor, the test can be carried out safely and quickly using small pressures. Either grind the device directly onto the instrument using a T-piece and a piece of hose, and mask off the openings of the probes/static holes. Use an overpressure of 100 hPa to check whether it can be held for one minute without visibly giving way. If this is not the case, isolate and repair the leak by disconnecting it. When connecting the hoses, it is best to heat them slightly with a warm air hairdryer. Cut off flared ends and replace hardened or short hoses.
    3. Defective pressure switch: A fault in the pressure switch (on self-starters/turbos) is also possible. In one case, the switch was defective and no longer switched correctly from static to the nozzle. The errors in this case are also very large.
    4. AHRS calibration: Another error can be due to incorrect calibration of the accelerometer, e.g. if the AHRS sensor was zeroed in a different position than where it was installed, e.g. lying flat on the table, and then inserted vertically in the installed position. This error is easy to determine, at startup the AHRS sensor should show 1.00 g, +-1% in the second line. If this is not the case, then "Reset" the AHRS Calibration (former Autozero), or (even better) execute the calibration wing/down procedure in the hardware setup. An AHRS license is not necessary for compensation; the accelerometer is always used for this purpose. The deviation in the event of incorrect AHRS calibration can be large if the error at that point is very large, such as a display that deviates by 100% corresponding to a display value of 2.00 g.
    5. Incorrect wing loading: It also makes sense to check the ballast. Due to an old bug in the XCSoar/XCVario driver, it could happen that the ballast value was completely adjusted when draining the water in the XCSoar. This should show ‘0 liters’ without water and the wing loading should correspond to the actual wing loading. To do this, make sure that a current XCSoar version is used and that the ballast also matches the actual ballasting. Also check the empty weight and the crew weight to see if this corresponds to the current weights. Compensation in straight flight can only work well if the wing loading is appropriate.
    6. In case electronic compensation is selected: Latest release also contains a PRESSURE method beside the traditional method EPOT for electronic compensation, that might be configured for "Electronic Compensation". This new method should be slightly better in dynamic conditions. There you find also an adjustemnt factor that can be taylored according to your vario readings on a push/pull test. To do so you can follow the follwoing procedure to level your TE compensation. 
      1. Select vario mode and fly in calm air (e.g. early morning) at speed of best gliding performance, e.g. 100 km/h, then smoothly accelerate to 150 km/h by increasing every second 10 km/h
        1. Vario readings are smaller than your expected sink, you are overcompensated, so downsize the adjustment factor, e.g. -10%. Repeat the test and reduce adjustment until the vario reading is same as expected sink speed
        2. If vario reading is larger than the expected sink value (e.g. -3 m/s insted of -1 m/s ) value, increase the adjustment factor by +10% and repeat the procedure until the reading is smooth. 

Twin-Seater Installations

  • Is there a control device for double seaters?

    For cost reasons, there is only one piece of hardware, but this can be connected to the master device as a WiFi client, or from series 22 onwards via a patch cable via CAN bus. Only the master device then has to be wired up and connected to Flarm, and also the pneumatic connections are not required for the second device. 

  • How to stop/disable “Wait for Master XCVario” mode on a Client device?

    Press the rotary knob for 3 seconds, then change the “Wireless Client” setting to one of the other options in Setup/Option/Wireless.
    For rather old software versions before 2021 that have not yet implemented this option, a software update is necessary first, as described in the manual. You can access the SW update if you press the rotary immediately after switching on, right after the SW version is displayed (first line).


  • Does the XCVario have a wind calculation?

    The wind calculation while thermaling is available and works well and delivers similar results that other circular wind approaches. All needed for that is a Flarm or another simple GPS source provided to XCVario. 

    There is also a straight live wind calculatio which requires a calibrated and compensated magnetic sensor on S2 with less magnetic disturbance on board. Typically this is possible in true gliders that do not have a lots of metal parts as is usual for turbo’s, self starters or cockpits of twin seaters. 

  • During the self-test, “Compass: Failed” appears sporadically or permanently

    There are various possible causes for a CAN sensor error:

    • First, please check the settings, is the CAN bus switched on and set to data rate: “1000 Kbit”, and is the Compass/Sensor Option set to “Enable CAN”?
    • If connected with a splitter, first connect the sensor directly without the splitter and then try it directly to S2 with a different cable. The CAN bus doesn't like long branch lines (but they actually only exist in two-seater cars), but the length itself doesn't play a role with a direct line. 
    • Then there is a data monitor under Options/Wireless, there you can look at the CAN bus to see whether binary data is scrolling through there and the RX counter is counting up, maybe the cable is wobbling, there are patch cables with unfavorably deep locking latches that may not be completely inserted Leave the socket plugged in or simply cause contact problems. We will soon also offer suitable cables in the shop.
    • If nothing appears on the monitor, check whether there are disturbing magnetic fields or metals nearby. A magnet, e.g. a loudspeaker, a current-carrying cable, or a DC/DC converter (of another device) can turn the sensor off for a while, it then only reports magnetic overflow but no longer a signal and is reported as “Failed” in the self-test . 
    • In order to rule out an older bug in the XCVario's software and also to see the latest improvements.  
    • If the connection still doesn't work and nothing shows up in the monitor ven in a location without magnetic interference, the sensor itself may have a defect, in which case please send in the defective sensor for diagnosis/repair.
  • Is a wind calculation using the HAWK (Anemoi) method (ZigZag) planned?

    This is not planned, the resources such as memory and CPU are not suitable for it. 

    The XCVario carries out the wind calculation using the magnetic sensor. The magnetic sensor must be installed optimally and compensated well. An automatic procedure is implemented for deviations (AutoDeviation). For this purpose, a wind calculation is carried out when circling and, together with the GPS data, an adaptive correction of the deviation for all courses flown is calculated backwards from the wind triangle. The accuracy of the airspeed sensor is also adaptively optimized. There is no need for manual compensation. The magnetic heading method converges quickly and can provide accurate results in environments with low magnetic disturbance.

  • Are there plans to implement a 3D variometer?

    We don't see a 3D variometer as being particularly effective; see also various videos on YouTube from people who have tested something like that. We therefore don't want to build a 3D variometer, but rather a device that reliably shows the actual rise, and that is and remains a 2D problem -> Where does it rise and how much? 

    Many experienced pilots with whom I spoke on the phone switch off their €8000 system, for example with the 3D HAWK, during thermal circles and center it according to the baffle plate. The usual comments are: “Not
    helpful”, “You have to get used to it”, “Only circle when the baffle plate and the HAWK are pointing upwards”, etc. Many of them, like me, have over 5000 flight hours. The conclusion: What use is the display of plus 2 m/s 'potential climb' if you don't get the beard centered, push, fly the wrong flap position or the wrong airspeed and Butto actually sinks?  

    According to my information, Larus currently (2023) does not yet have a fully developed system, nor a driver in XCSoar, LK8000 or other common open source products. The system and also the wind calculation will only work reliably and quickly with two RTK-GPS antennas. The costs and effort for this system, including the antennas, which have to be installed at the appropriate distance, are not exactly small. In CFRP hulls, which we
    have practically everywhere today, this is only possible within the canopy frame. A challenge in terms of reliability, visibility, optics, and also with regard to the required minimum distance between the antennas in single-seaters. Larus currently needs a somewhat idiosyncratic OpenVario clone. There is currently no sign of a timely catchup with XCSoar's growing feature set. It will certainly take some time until the Larus driver is widely available. Very few developers are
    working on the 'quasi' open source fork, and there is no evidence of an active process of delivery to Larus, as there is from Larus to other projects such as XCSoar. It has now also been recognized that for reliable wind calculations, for example, the side slip (sliding angle) must also be calculated and taken into account. 

    A 3D variometer uses other sources, such as fast and accurate GPS and Inertial System Information (AHRS), to estimate what the air mass around the aircraft is doing, which manufacturers call “potential climb”. However, these GPS data, which are very noisy and delayed, especially in the altitude display, are not particularly helpful. The system also requires a precise digital model of the aircraft. These models only exist to a very limited extent today. For example, the polar is only defined for a load multiple of 1g. If the load multiple differs, a theoretical model is required. Many things are missing in this model, such as the specific angle of attack or the slide angle. This means that if the brake flaps are extended, or if the aircraft is in slip flight, or briefly stalled, or if the load multiple is not equal to one, then these models do not fit and the climb displayed differs greatly from reality. We are of the opinion that a 3D system can currently only make
    sense as an additional display, but a conventional variometer is indispensable. 

    The XCVario is also working on improved TE compensation, including acceleration and gyro data, and a quasi 3D mode. The main purpose of this is to achieve an even better display, especially in fast straight flight or dolphin flight, with the aim of being able to do without a TE nozzle.

  • When calibrating the magnetic sensor, how to get all axes into green?

    Calibrating the magnetic sensor does indeed require a bit of skill and should be carried out in an area free of metal and magnetic interference fields. 

    The sensor does not have to be swiveled, but rather aligned exactly to the earth’s magnetic field vector in all 3 spatial directions and held still for a short time so that one axis shows a maximum and the other two axes show a minimum. Then do the same in the opposite direction to the earth’s magnetic field. A video with corresponding explanations is here

    Once calibration has been completed, the values ​​can be displayed under “Show” in the “Sensor Calibration” menu. If the “Scale” values ​​differ by more than 10%, there may be a hardware error. 

    If necessary, repeat the calibration in a different location, e.g. further away from magnets (e.g. loudspeakers) and metals; typically the values ​​are between 95 and 105.

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