olnico

Hi guys, I had to setup a RRS system for a friend of mine with dual AR9000 Spektrum receivers.

The RRS/Royal user manual can be misleading for 2.4Ghz users.

It appeared that my friend did setup his system as for PPM receivers. THIS WILL NOT WORK on 2.4 Ghz systems.
Although these systems are not PCM, at the end of the range or in case of jamming, the faisafe function will act as for PCM systems.

So you have to setup the RRS/royal system as if it was hooked on two PCM receivers.
Namely both RRS/Royal FS1 and FS2 inputs have to be connected to a receiver channel. This channel has to be programmed to go to one of its travel extremity in case of failsafe condition. There are two options on Septrum systems at this stage: either to use the throttle channel and stick to the normal binding procedure or use another channel and bind the system using the Smartsafe procedure.

1. Throttle channel used as FS activation:
one of the receiver Throttle channel ( lets say THR.1 or the throttle output on receiver 1 for example ) will need to be connected to both FS1 on RRS/Royal and on the engine ECU. The other receiver Throttle channel THR.2 will simply go straight to FS2.
This setup has the advantage to "save" one channel for people who absolutely need all the channel capability of their receivers. The drawback is a possible power and signal problem to the usually very sensitive ECU input. Although I have not had any problem so far with a normal welded Y cable, one answer to this could be to use an amplified Y chord.
Note that it would be absolutely imperative to use the Jetcat faisafe programming as described in the Jetcat engine user manual for this setup, otherwise each time you put the engine to full throttle, the RRS/Royal unit would believe both recievers are in a faisafe condition !!!

2. Another channel used as FS activation:
If you can afford loosing one channel on both receivers, then a better option would be to connect one of your receivers channels to the RRS FS inputs.
For this example I will consider using AUX3.1 and AUX3.2 ( AUX3 output on receivers 1 and 2 ). This channel usually refers to the brake channel and takes order by default from the left side lever ( right side lever on mode 1 Tx ).
First of all make sure that the lever is connected to the channel in the switch assignment menu. Then make sure that you have 100% travel on each side.

2.1. First step: connecting and troubleshooting.
Connect AUX3.1 to FS1 and AUX3.2 to FS2. Switch both TX and RX ON. Verify that when the lever is in the middle the RRS/Royal screen indicates both 100% and both arrows ->. Now put the slider on one extremity and verify that you have both percentage decreasing and that both arrows has turn into two underscore signs _ . This means that the system believe that both receivers have gone to failsafe. You will note that your radio still works since the RRS/Royal will do nothing in that case ( no switching possible since both systems are supposedly on failsafe ). THIS STEP IS VERY IMPORTANT since it will enable you to make sure that both FS channels are working correctly. I have had one instance of FS channel not working out of 3 RRS/Royal units. This is dangerous since in case of jamming/masking/end of range the system would not switch and you would crash.

2.2. Setting up the failsafe:
Now you need to bind your system using the Smartsafe procedure. Make sure all levers/control sticks are in the expected position. In particular, our brake lever has to be set on either extremity position.
After the binding is done we can do a failsafe verification.

3. RRS/Royal redundancy verification

When you have finished setting up your system and programming the failsafe function, it is essential to check the redundancy feature of the RRS/Royal unit.

3.1 Power interruption and failure redundancy test.
Switch both Tx and Rx ON.
Simply unplug one of the FS plug from the RRS/Royal side and check that the corresponding % decreases and that the associated arrow becomes an underscore on the RRS/Royal screen. Then do the same on the other side and check for the same consequences. The radio control should remain normal at all times.
This procedure is testing the capability of switching in case of a power failure or hardware receiver failure on one side.

3.2 Basic failsafe redundancy test.
Switch both Tx and Rx ON.
Turn your Tx off and check that you have two % decreasing on both sides on the RRS/Royal screen. You should also see two underscores.
Your system will be on hold if you have plugged the THR channels on the FS input of the RRS/Royal unit, with the engine shutting down according to your ECU programming.
The system will revert to the pre-programmed positions if you have used the AUX3 channels.
This procedure is testing the capability of sensing a dual failsafe condition. The unit will not switch since both receivers are sensed in FS at exactly the same time.

3.3 Advanced failsafe redundancy test.

The idea is to simulate a masking condition on the receiver used by the RRS/Royal as primary source to force a switching to the other receiver and check the operation of the system.
This is really easy to do with an AR9100 receiver since you would simply have to remove all the remote antennas connectors on the sides of the unit while it is powered and connected to the Tx to create a failsafe condition.
On other receivers the problem comes from the antennas included in the unit.The only way to test the system in that case would be to remove the existing remote antenna and to mask the on-board antennas with an aluminium tube. Since the RF link is extremely strong, you will also have to reduce the TX power by pressing the bind button and walk away as for a range test.

In practical:
Prepare your aircraft in an open area as if would would do a range test.
Switch your TX and Rx and check that everything is working.
Check what receiver the RRS/Royal unit is using ( will be shown as a plain arrow, the non used one will display an empty arrow ).
Unplug all the remote antennas connected to this receiver. At this point if you are running dual AR9100 you will see the plain arrow on the used receiver turn into a underscore and the percentage pf this receiver starting to decrease.
In case of other receivers you will then have to cover the on-board antennas with the aluminium tube. Make sure that the end of the tube is crimped.
Then press the Tx bind button to reduce the Tx power and let your assistant walk away as for a range test. You will see at one point the antennas LEDs starting to blink on the masked receiver and the RRS/Royal will start to switch over from the primary rx source to the secondary. Make sure that you get the full control of your plane during this process.
A flight log can be interesting here on both receivers to see more precisely how the system handles in such a case.

Performing these three checks is the only way to test completely the redundancy capability of your system and I strogly recommend to do it initially and once per flying season.

Samir

Many thanks again Olivier..I have now programmed this set up it on all three Jets and flown it on the Elan last week when it worked perfectly just as advertised.
I couldn't have asked for a better redundancy solution.
Two Lipos 3400 or two Duralite" 123" 4000 mah batteries connected through a Power Box sensor switch to the Power Box RRS system to two seperate Spektrum AR9000 or Jr recievers, the perfect solution in my view .

KamikazeParanoia

Would there be any differences in setup for a large electric (3000W) 3D model? Im thinking I should have the ESC on failsafe if necessary to cut the throttle if the worst happens? (Im new to spektrum)
I will be installing the Powerbox RRS with two Spektrum AR7600 receivers, 5 16kg Savox servos, speed controller and Spektrum flight log

Would/should I have a Spektrum Voltage Protector (capacitor) plugged into each receiver? or just one throughout the entire setup? Into the powerbox RRS maybe? could two cause harm? (overvoltage?) Or just additional protection?


Thanks Oli, you're a real gem!

olnico

In that case you can use point 1 above.
Plug the THR channel of receiver 1 in FS1 plug of the RRS system and into your ESC ( Y cable ).
Plug the THR channel of receiver 2 in FS2.

Avoid using a BEC system since the Spektrum receivers are known to be sensitive to voltage drops. In that case, you'd have one Rx battery plugged to each receiver ( 2 rx batteries total ) and you would not need to add a voltage capacitor to the receiver.
The purpose of the capacitor is to avoid a sudden voltage drop that would result in a receiver re-boot.

KamikazeParanoia

I have a single FlightPower EON-X-RX 3200 2S2P Receiver battery via Flighttech 8A Linear Voltage Regulator (FT8AVR) to the Spektrum AR7600, no BEC, will that be ok?
I already have the voltage protectors so could use them (or one) to prevent voltage drop in extreme 3D manouvers if no ill effect would result?

Many thanks