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Strange behaviour Jeti Assist rx and spool up..

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Strange behaviour Jeti Assist rx and spool up..

Old 09-23-2020, 05:56 AM
  #26  
Remco45
 
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That is strange, because how would the Assist (software) have access to the Turbine firmware in the turbine ECU?
Because you state that it is the same turbine brand, perhaps there is something wrong with their firmware or hardware.

EDIT: crossed Wayne post above: I agree with him also.

Last edited by Remco45; 09-23-2020 at 05:58 AM.
Old 09-23-2020, 06:14 AM
  #27  
Bobneal1
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I have a Merlin 200XBL. The turbine settings were changed in the ecu by the telemetry link from Jeti. I got huge flaming starts with the turbine . I could reset the turbine settings manually and disconnect the telemetry and the engine would run fine. As soon as I reconnected the Xicoy telemetry unit the settings would be changed. Gaspar finally sent me a telemetry unit with no up link capability and the problem went away. I spoke with Jeti experts the consensus was something in the Transmitter was up-linking the changes to the ecu. I deleted all the Jetibox pages and nothing would help.

The point is, you don't know what is being up linked and down linked between the transmitter and the rx in the aircraft especially if you have telemetry. Do you have turbine telemetry?

Just a thought.
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Old 09-23-2020, 06:47 AM
  #28  
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Wow...that's strange, I've asked some guys on a European forum (German Jetiforum) if someone had similar experiences.
Old 09-23-2020, 10:43 AM
  #29  
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Originally Posted by Bobneal1 View Post
I have a Merlin 200XBL. The turbine settings were changed in the ecu by the telemetry link from Jeti. I got huge flaming starts with the turbine . I could reset the turbine settings manually and disconnect the telemetry and the engine would run fine. As soon as I reconnected the Xicoy telemetry unit the settings would be changed. Gaspar finally sent me a telemetry unit with no up link capability and the problem went away. I spoke with Jeti experts the consensus was something in the Transmitter was up-linking the changes to the ecu. I deleted all the Jetibox pages and nothing would help.

The point is, you don't know what is being up linked and down linked between the transmitter and the rx in the aircraft especially if you have telemetry. Do you have turbine telemetry?

Just a thought.
Actually that would be something in the receiver was sending data that the Xicoy telemetry unit didn't understand and as a result handled incorrectly. That is still 100% a Xicoy firmware bug. Jeti uses these interfaces to send telemetry data, firmware upgrades, etc. If a 3rd party vendor designs a device intended to connect to that interface it's 100% on them to understand everything that can be sent across that interface and ensure that it's always handled correctly so that they don't encounter these types of problems.

Last edited by wfield0455; 09-23-2020 at 10:52 AM.
Old 09-23-2020, 10:21 PM
  #30  
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Originally Posted by wfield0455 View Post
Actually that would be something in the receiver was sending data that the Xicoy telemetry unit didn't understand and as a result handled incorrectly. That is still 100% a Xicoy firmware bug. Jeti uses these interfaces to send telemetry data, firmware upgrades, etc. If a 3rd party vendor designs a device intended to connect to that interface it's 100% on them to understand everything that can be sent across that interface and ensure that it's always handled correctly so that they don't encounter these types of problems.
Actually this particular issue that we found only happening in this particular customer, was tracked to the JetiBox emulator operation, sending to the ecu random keystrokes. The Jetibox is a feature of Jeti radios allow to navigate through the menus of the ecu from the transmitter, it transmits keystrokes from transmitter buttons. The ecu reacted the same as if someone was clicking on the ecu buttons, so a particular keystroke sequence could upset the ecu parameters. We never arrived to know if the TX was sending these keystrokes on its own, or was noise. The Jeti protocol is robust, except the Jetibox buttons, that is a single byte transmission without any protection (CRC, checksum, etc) so the random noise in a particular installation could be randomly interpreted as a keystroke.



As said, seen only once.



Gaspar

Old 09-27-2020, 06:00 AM
  #31  
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Originally Posted by Daveeast View Post
Now over five occurrences of loss of turbine control in flight, the last flight turning on the assist for the first time on a new setup, and after several minutes the turbine is no longer communicating, this problem has damaged more the one of my models.

The Assist appears to be crashing the turbine software, as there is no control or ability to look at the turbine status once on the ground. I have even had this occur on one occasion, whilst carrying out taxi tests. we have spent a lot of time trying to replicate these failures to no avail.

This has been with several different models and different hardware (same turbine brand) and even independently set up by other experienced users.

Jeti are aware of my issues and at least are in discussion about it but as yet no answer.
Can you tell us a little more about your installation ? Are you using the Assist stand alone or is it connected to a Jeti Central Box ?
If stand alone do you by any chance had the "Stabilize Ex Bus" control in the Assist set.
I'm guessing you must have Telemetry unit connected. Is is connected via Ex Bus or Telemetry/EXT ?

Have you had any further response from Jeti ?



Old 09-27-2020, 06:17 AM
  #32  
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The setup has been via both a CB 200 and 210, using Assist 6 and 7, back up RSat and on one airframe a 900 as well. All configuration has been not to allow intelligent failsafe. These occurrences have not been due to failsafe as the other channels have functioned normally.

We bench tested and could not reproduce fault thought maybe now we need to consider doing further tests in a closed environment to gett the frequencies or noise to play a part.

Cheers D
Old 09-27-2020, 07:55 AM
  #33  
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Originally Posted by Daveeast View Post
The setup has been via both a CB 200 and 210, using Assist 6 and 7, back up RSat and on one airframe a 900 as well. All configuration has been not to allow intelligent failsafe. These occurrences have not been due to failsafe as the other channels have functioned normally.

We bench tested and could not reproduce fault thought maybe now we need to consider doing further tests in a closed environment to gett the frequencies or noise to play a part.

Cheers D
Thanks for the reply. Since the Assist is connected to a central box you must have "Stabilze Ex Bus" in order to stabilize servos connected to the Central Box. Is there any sort of turbine related telemetry device connected directly to the Assist ?

Based on Gaspar's previous post I'm just wondering if the ECU could be interpreting basically random stabilization data from the Assist as Jeti Box data and causing it to reprogram ECU parameters, etc but for that to happen I would think it would need to be connected directly to the Assist by something other than the throttle channel.

Just trying to figure out your setup so I can understand what may possibly be happening so I and others can avoid similar situations...



Old 09-27-2020, 09:35 AM
  #34  
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The assist was on and had flown several times ( Maybe 10 Flights) without issue. Switch it on, stabilization was fine, but no tuning was carried, then around five minutes into the flight loss of turbine control about 20% thrust, which then meant flying to flame out, no effect by disarming or turning it off. On the previous loss of control flights, trimming the engine off failed to shut off the turbine, other channels were normal. After landing the turbine software does not initialise the HDT. The turbine pump has to be stopped by pulling the power.
Old 10-02-2021, 10:08 AM
  #35  
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Originally Posted by Gaspar View Post
Actually this particular issue that we found only happening in this particular customer, was tracked to the JetiBox emulator operation, sending to the ecu random keystrokes. The Jetibox is a feature of Jeti radios allow to navigate through the menus of the ecu from the transmitter, it transmits keystrokes from transmitter buttons. The ecu reacted the same as if someone was clicking on the ecu buttons, so a particular keystroke sequence could upset the ecu parameters. We never arrived to know if the TX was sending these keystrokes on its own, or was noise. The Jeti protocol is robust, except the Jetibox buttons, that is a single byte transmission without any protection (CRC, checksum, etc) so the random noise in a particular installation could be randomly interpreted as a keystroke.



As said, seen only once.



Gaspar
I know this is an old thread, but I had the exact same issue with my Graupner HoTT system and the Xicoy telemetry adapter. I plugged the adapter to my telemetry port on my Graupner RX and the ECU settings started changing randomly, I could never find out why this happened and just disconnected the Xicoy telemetry adapter and tossed it on my parts bin.
Old 10-02-2021, 11:36 AM
  #36  
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Default My Jeti radio made changes to my ECU

My Jeti changed the settings in my ECU through the telemetry and caused the engine to massively flame during starting and damaged my airplane.

Bob Neal

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