Competition SRS RF-Flight Recorder

  • I have a new Competition SRS installed in a new 40% IMAC plane, with two Futaba R7003SB receivers connected to RX1 and RX4 ports via SBus and telemetry enabled (SBus2 on Receiver1). The plane (about 20 flights so far) is not showing any abnormal radio behavior, however yesterday I checked for the first time the RF parameters via telemetry on my Transmitter (Futaba T14SG) and noticed a number of Fades on both receivers (probably normal), a few Lost Frames and a number of Holds (8), actually larger than the Lost Frames. Because of the Holds, I am concerned about the safety of my setup. Is this a sign of poor radio link and what should I do, if anything, to correct it?

  • I did not feel any Hold, but it may have been brief enough to go unnoticed. The number of Fades were different for each receiver. The Lost Frames number is not associated with a specific receiver, at least in my radio system, and in the RF-Flight Recorder screen of the PowerBox. There is just one count for it and, if I remember well, it was not very large, actually smaller than the number of Holds, which was 8 in one flight.

  • Hello,


    cannot imagine that the numbers of Hold is higher than the number of lost frames. To make it clear: this is mpossible: A Hold is when both receivers have a lost frame at the same time... so without Lostframes of both receivers- no Holds.

    Maybe you can document this count screen next time with a picture, then I can tell you if everything is fine or not.

  • That is exactly what I thought and why I was so puzzled by a Holds count higher than the Lost Frames count! I wonder if there is some firmware bug, either in the Radio or the PowerBox, by which the two counts are reversed. Regardless, both counts were non-zero and this is a concern to me. Next time I fly this plane, I will take a picture of the screen and send it to you.

  • In the meantime, please clarify the relationship between "data packets" and "Frames". Also, is the "Lost Frames" count, as reported by the PowerBox, associated with a specific receiver (out of the two installed), or is it a combined count, or perhaps indicative of both receivers being simultaneously unable to provide a data packet to the PowerBox, for a period of time shorter than a Hold? I would like to better understand the definitions for these RF parameters, as the PowerBox manual is somewhat unclear on this subject. Is there any better document that I can access?

  • I did a bit of experimenting today, with the plane on the ground (i.e. not flying). Both receivers were connected via a modified extension that allowed me to interrupt the signal lead on the S-Bus to the PowerBox. The first picture shows the RF-Flight Recorder screen with both receivers connected normally. I then interrupted the signal lead for Receiver 2 serial bus. The Antenna Fades on RX4 started incrementing rapidly, as expected. Reconnected Receiver 2 and interrupted only the signal lead for Receiver 1 serial bus (power and ground and the SBus2 telemetry link were still connected) and I could see the same parameters on the Transmitter screen (Telemetry Monitor). Now RX1 Antenna Fades were incrementing. Then I disconnected the signal leads of the serial bus for both receivers. On the Powerbox screen I could see both Antenna Fades and Lost Frames incrementing quickly, with one Hold reported. However the Transmitter display froze. It restarted again only after I reconnected the signal leads. Powerbox continued reporting correctly (Picture 2), but the Transmitter refreshed only the Antenna Fades, not Lost Frames and Holds, which remained stuck at the odd numbers shown in picture 3 (no Lost Frames and 255 Holds!).

    I now start wondering if what I had noticed before beginning this thread (that is, more Holds than Lost Frames being reported) was indeed related to some bug of the Futaba system and its telemetry link and makes me loose confidence in its reporting.

    Your thoughts? Is there possibly a safety problem in the control link of my plane or is it just a telemetry issue?

  • Thanks for the reply. There are really two remotely-reported values that seem out of order and inconsistent with what is reported by the Powerbox on its screen, the Lost Frames and the Holds. Will you/your people be checking the Teleconverter (I assume its firmware) for errors, or do I need to do anything on my end?

  • My Futaba Transmitter T14SG was updated in May to Ver 7.0, which still appears to be the latest, from what I can tell on the Futaba web site.

    I flew the plane today three times and I can confirm that, after each flight (about 10 minutes long), both Powerbox and the Transmitter telemetry screen were reporting the same number of Antenna Fades, about 40-70 for each receiver. However, Powerbox reported only a very small number of Lost Frames (1-3) and zero Holds. These two numbers were consistently reversed in the Transmitter telemetry screen (that is zero Lost Frames and 1-3 Holds).

    As you already indicated, it does appear there is an error in either the Futaba telemetry or the way PowerBox reports the parameter values to the telemetry, by which the two numbers (Lost Frames and Holds) are reversed.


    At least it appears there is no big issue with my plane's control link. I assume the small number of Lost Frames is normal and acceptable. Correct?


    I suggest that PowerBox work with Futaba to correct this error, where ever it resides, and verify that other Futaba transmitters don't suffer from the same issue.

  • Hallo,


    ich habe eigentlich das selbe Problem nach Rücksprache mit Powerbox wurde ich zus. an das Forum verwiesen.

    Meine T 18 zeigt die Fades korrekt, Lost Frames werden am Sender als Hold gezeigt und Hold werden gar nicht gezeigt.


    Leider weiß ich nicht woran es liegt , Prinzipiel könnte es auch am Softwarestand der T 18 liegen , da der Kollege hier das gleiche

    Problem hat tippe ich aber fast darauf das die Werte im Teleconverter verdreht sind, wobei aber wie gesagt die Holds gar nicht

    gemeldet werden.

    Ich will auch nicht vorschnell neue Software Versionen am Sender durchprobieren.

    Mein Problem ich möchte in der T 18 auf Holds eine Warnschwelle setzen mache ich das geht nacht ein paar Lost Frames

    zu unrecht die Warnung los




  • Since it appears the last few posts are still relevant to the thread I started in English, can anyone please summarize their contents in English?

    In general, it would seem considerate to stay with the language the thread started....


    Also, can Richard please indicate if it is normal to have a few Lost Frames (not Holds) during a 10-minute flight?

  • Hallo,


    habt ihr die Sache beim Teleconverter schon überprüft, bin kurz davor auf 2.5.0 runterzugehen (T 18).


    Funktioniert es da sicher werden beide Werte richtig angezeigt Lost Frames und Hold .



    PS: die FX 32 eines Kollegen zeigt es ebenfalls so wie die T 14 oben also auch verdreht !

  • schade das hier nichts mehr kommt ein einfaches wir sind dran , momentan keine Zeit dafür ,eine Antwort wäre schön.

    Aber keine Antwort ist eben auch eine Antwort !

    Mir reicht auch die Aussage mit Software ... funktioniert es 100 % tig.

    Beim Kollegen mit Software 2.5.0 wird es laut seiner Aussage auch falsch angezeigt.

    Für mich ist das Future einfach sinnvoll ,meldet der Sender Holds kann man den Flug beenden und auf Fehlersuche gehen !


    PS vielleicht liegt es auch daran das ich mich an den Thread von grecchia angehängt habe soll ich einen extra für T 18

    und SRS Flight Recorder eröffnen ?