350 QX  &  DX 6  Telemetry Log

 

 

DX6 Telemetry Flight Log

The 1st gen. 350 QX has a short (30mm or 1/4 wave length) copper wire receiver (RX) antenna that just comes off the back of the flight control (FC) board. Now the new 350 QX2 has a separate board for the RX and a longer antenna system that extends down the landing gear leg and a 2nd shorter one that is in the body shell. I'm wondering how much this has improved communication to the 350 QX2. I'm assuming that this change/upgrade was done because of a weakness in the original design. If nothing else I'm guessing that the range of the QX2 has been improved.

I don't normally fly with my SD card in my DX6 so I installed it and in the menu activated telemetry logging putting it on a switch. At this time I only have a small sample of flight logs to review. As I'm just starting to look at this feature I welcome any comments that will help me understand the results of the log data. Please email me if you can assist in my learning curve. I understand this is only basic telemetry as the QX is not using a TM1000 module LINK and I will not get voltage, GPS or other data from the model only the DX6 / QX RX handshake info.


Here is all that is mentioned about Telemetry in the DX6 manual.



 

Then I collected this information from the Spektrum website:

The Flight Log is an optional component that was originally designed for testing, but now it is offered as a handy device that gives you a clear digital readout of your radio performance. The Flight Log is not required, but for complex aircraft it provides an intuitive analysis of the overall performance of the radio installation. Some of todayís models can be very demanding. The Flight Log ensures that your system is working properly and you have optimized the radio installation.

The Flight Log provides the following information:

  • System VoltageóReceiver Pack Voltage
  • Antenna Fades
  • Frame Losses
  • Holds

Guidelines for DSMX:

  • Holds - Holds are unacceptable. If a hold occurs, please investigate and correct the issue before next flight.
  • Frames - < 100 - In conventional models during a 10 minute flight, frames should typically be less than 100 on all receivers.
  • Fades - Use Fades for comparison only. All attached receivers should have similar Fades. If not, investigate poorly performing receivers (location, antenna orientation, etc) and correct.

The Flight Log displays the following data:

  • Displays antenna fades
  • Displays frame losses
  • Displays fail-safes
  • Receiver battery performance

 


Frame Loss: Signal degradation to the degree that it loses one whole frame of data. A Frame is the chunk of data that delivers all the signals to all the channels happens in either 22ms or 11ms depending on how you set the particular model.
Hold: 45 consecutive frame losses (about one second of signal loss depending on data rate that is set in particular model Frames should be low, if high try rearranging antenna and satellites. You want NO holds, if you get holds don't take off or land right away.

Next I found the free Telemetry Log Viewer by kevinww from HeliFreak LINK and installed it on my PC.

Here is a sample from one of my logs. It looks like the column values are cumulative, meaning that where it shows frame loss of 26 is from the beginning of the log and not in the single sample for the time line shown. So in this log the one hold was posted in the very first entry in the log and I'm thinking it's not important. I hadn't even started my props yet. The minor program issues that I reported to the author have been fixded in this version.

 

Frames is Frame Losses, simultaneous fades on all antennae.

Hold is 45 consecutive Frame Losses, you should ideally have zero during a flight. If you have more than a couple frame losses and even one hold you need to change the position or orientation of one or more antennae.

A,B,L R, are the individual antennae, actually receivers. It shows signal fade on each individual one. Not used in the basic 350 QX without a TM1000.


I plan on capturing more data and when I do I'll try to note what distance I was from the QX or at what altitude it was at. I've flown my QX almost 800 feet out from the DX6 and still returned it OK. I hope to hit 1,000 feet distance sometime soon. However one time at distance I did loose control and crashed into a 2nd story house roof. I was not logging telemetry at the time. That issue could have been almost anything.

Tip: When flying the 350 QX with the DX6 do not turn on the telemetry "(12) Flight Log" alerts. Your TX will begin sounding alarms and the screen may lock you out of the normal home screen. This is because the default of 5 seconds on the alarm is very quick. I believe that if you just roll your scroll wheel while bound you can review the telemetry counts in the display window. If you do activate the flight log I suggest only the "HOLDS" be monitored real time as opposed to being written to the log file.

My Flight Log screen looks like this:

Frames: > 20   Inh
Holds:   >   2   Voice

Status Reports: Inh
Warning Reports: 10 sec

And on my Stagility model setup I set switch "C" to turn Telemetry on and off and included the voice commands.

The "Clear" button will acknowledge the count if pressed when the Telemetry screen is displayed. I'm unable to test this right now.