FrSky Redundancy Bus 10 - RC Groups
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Dec 15, 2016, 11:36 AM
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Mini-Review

FrSky Redundancy Bus 10


This is the first part of my review of the new FrSky Redundancy Bus 10 (RB10) (https://www.rcgroups.com/forums/show...10-%28RB-10%29) made possible by FrSky / Horus RC

The Redundancy Bus 10 is a small 8 (16) channel redundant power / RF unit with protective outputs and telemetry feedback. Some reasons to use such a device are:
- High power / torque servos
- Valuable aircraft
- Difficult RC installation
- Lots of RF shielding (metal, carbon)

The RB10 has 3 main features: Redundant RF, Redundant power, Output over current protection

Redundant RF
The RB10 receives it's signals from 2 S.Bus receivers (both normal and reverse S.Bus are accepted). When both receivers receive a valid signal receiver 1 is used. If receiver 1 does not receive a valid signal then receiver 2 is used but only if receiver 2 has a valid signal. If receiver 1 is in failsafe receiver 2 will be used unless receiver 2 is in failsafe also. If both receivers are in failsafe the output of receiver 1 is used unless receiver 1 has not output at all. This makes the system uses the best signal of the 2 available. The S.Bus data stream is used to output a PWM signal on output 1-8 and the entire S.Bus stream is outputted on output 9 (S.Bus). The 8 PWM outputs have 2 modes: 50Hz (for compatibility with analog servo's) and S.Bus sync. For the quickest response with fast digital servo's the sync mode can be used but for most applications the 50Hz mode will be fine. The S.Bus output can be used with S.Bus to PWM expanders to connect up to 16 normal servos. Be aware that with 8 servo's connected to the S.Bus output they all share the same e-fuse!

Redundant Power
Redundant power is achieved by using the battery with the highest output. If 2 identical batteries are used the voltage drop under load will make the batteries switch and effectively both will be used. This will be tested more detailed later. Both batteries are separated from each other so a depleted / shorter battery will not affect the other battery. The RB10 has the option to detach the battery with the lowest voltage to prevent it from drawing power from the RB10.

Output over current protection
Over current protection is one of the nicest features and 11 outputs are protected: PWM 1-8, S.Bus, RX1 and RX2. Each protected output shuts down if a current of 2.5A or more is drawn for a long time or if the current is over 5A for a shorter time (it depends on the load / ambient temperature). The best feature is that a short circuit (damaged cable, burnt servo motor) will shut down the output immediately. This requires a receiver battery that can provide a high current because the e-fuses work the best when the over current is the highest. When you use a weak battery the voltage will drop to much when under load and e-fuse will take a while before it disconnects the output. If the voltage drops to much the receiver can shutdown and take a short time to reboot. This could result in a dangerous situation. Recommended are 2 batteries that can supply at least 10A constantly. Most powerbox systems want to provide enough current to the damaged servo so the wires will burn through but this solution is much nicer and could prevent much more damaged.

With 10g it is a very light and small box roughly the size of a X8R. It can be powered by 2 very small receivers like a XSR and a XM+ to create a small and compact solution that allows the receiver to be placed at the optimal location in the plane. The RB10 sits at the optimal location where all servo and power cables meet allowing for the optimal installation.

But wait, there is more Since FrSky has telemetry on all X series receivers (except for the XM / XM+) this little RB10 has a very nice telemetry option also. The RB10 provides telemetry output for voltage of both batteries, the status of the receivers and the status of the e-fuses. There are also sensor for current and capacities but there is no measurement so those are useless (used in the larger Redundancy Bus). The best feature is that sensor RBCS not only shows an overload situation but it even tells which output is shut down I have not seen that before in any system.

So far my thought about the RB10:
+ Light and compact. Should fit any model
+ Protected outputs for added safety. This protects wires and other components
+ Useful telemetry output. Nice to be able to check the logs if you suspect something was wrong in a flight
+ / - S.Bus is protected by a single e-fuse so a few high power servo's could mean a problem
- One key feature is missing for me (and should be very easy to add, more on that later) : No on / off switch. This would make the RB10 plain perfect.


Next part will be the installation in a plane and some flying result / logs. I am waiting for my XSR's for that.
Last edited by Tadango; Dec 16, 2016 at 02:21 AM.
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Dec 15, 2016, 12:30 PM
Registered User
Quote:
. Some reasons to use such a device are:
- High power / torque servos.
In my opinion I don't see this unit appropiate at all to be used with high torque servos, if those specs are correct.
Servos like mks, futabas bls, etc with torque above 300 oz-in can easily pull more than 5A for a few seconds during 3d flights.
On my 120cc I have measured short peaks of 60A during high energy manoeuvres using 8 bls 172.
Dec 15, 2016, 12:40 PM
Registered User
Quote:
Originally Posted by Ciusna
In my opinion I don't see this unit appropiate at all to be used with high torque servos, if those specs are correct.
Servos like mks, futabas bls, etc with torque above 300 oz-in can easily pull more than 5A for a few seconds during 3d flights.
On my 120cc I have measured short peaks of 60A during high energy manoeuvres using 8 bls 172.
I will test with such a load to see how it handles it. Good point.
Dec 15, 2016, 01:10 PM
Sagitta Fanboy
Quote:
Originally Posted by Ciusna
In my opinion I don't see this unit appropiate at all to be used with high torque servos, if those specs are correct.
Servos like mks, futabas bls, etc with torque above 300 oz-in can easily pull more than 5A for a few seconds during 3d flights.
On my 120cc I have measured short peaks of 60A during high energy manoeuvres using 8 bls 172.
The full on RB is likely what you'd want there.

The RB10 is a smaller system for smaller applications with less demanding draws, but which requires more protection than the RX8R provides.
Dec 15, 2016, 01:21 PM
Registered User
Quote:
Originally Posted by mawz
The full on RB is likely what you'd want there.

The RB10 is a smaller system for smaller applications with less demanding draws, but which requires more protection than the RX8R provides.
According to the specs the overload protection is the same for both.
Dec 15, 2016, 02:20 PM
Registered User
Quote:
Originally Posted by mawz
The full on RB is likely what you'd want there.

The RB10 is a smaller system for smaller applications with less demanding draws, but which requires more protection than the RX8R provides.
Yes, both units share the same overload protection.

An example, bls 172 @ 6,5A :

Futaba BLS-172SV Test (0 min 53 sec)


Mks 777 @>5A constant
MKS HV777 Servo Teat (0 min 53 sec)


And this is a x8r oveload test with savox 1270 servos. Around 6-7A no problem ( both servos are connected to the same channel on the receiver)

X8r test overload with 2 savox 1270tg (0 min 48 sec)







Both units share the same problem and the lack of an integrated switch on the full RB is a big fail from frsky
Dec 15, 2016, 02:34 PM
Taranis Tyro...
MattyB's Avatar
Quote:
Originally Posted by Ciusna
....Both units share the same problem and the lack of an integrated switch on the full RB is a big fail from frsky
Why? Switches are rubbish - they are an additional and unnecessary failure point. Personally I avoid fitting them like the plague. If you want a switch by all means fit one, but don't inflict the unnecessary weight and additional failure point on all of us.
Last edited by MattyB; Dec 15, 2016 at 02:57 PM.
Dec 15, 2016, 03:06 PM
Registered User
I need a switch. No plane without a switch. The RB10 already has a dual switch, just nothing to control it (yet).
Dec 15, 2016, 03:09 PM
Registered User
Quote:
Originally Posted by Ciusna
Yes, both units share the same overload protection.

An example, bls 172 @ 6,5A :

https://youtu.be/LmOXEoGW-lQ

Mks 777 @>5A constant
https://youtu.be/cuBkhHAEywY

And this is a x8r oveload test with savox 1270 servos. Around 6-7A no problem ( both servos are connected to the same channel on the receiver)

https://youtu.be/EpH22YmfVgk






Both units share the same problem and the lack of an integrated switch on the full RB is a big fail from frsky
If a servo is jammed like this it should be cut off, at least in my planes.
Dec 15, 2016, 03:10 PM
Registered User
Quote:
Originally Posted by MattyB
Why? Switches are rubbish - they are an additional and unnecessary failure point. Personally I avoid fitting them like the plague. If you want a switch by all means fit one, but don't inflict the unnecessary weight and additional failure point on all of us.
Tell that to Powerbox systems , Emcotec , Jeti , Smartfly, Booma RC, Spektrum (powersafe) and all their customers.

A Jeti cb200 is 30gr, a Smartfly Micro-14F is 37gr and have an integrated switch. Frsky's RB is 37gr...
Last edited by Ciusna; Dec 15, 2016 at 03:25 PM.
Dec 15, 2016, 03:14 PM
Registered User
Quote:
Originally Posted by Ciusna
Tell that to Powerbox systems , Emcotec , Jeti , Smartfly, Booma RC, Spektrum (powersafe) and all their customers.

A Jeti cb200 is 30gr, a Smartfly Micro-14F is 37gr and have a integrated switch. Frsky's RB is 37gr...
Please email FrSky. I tried to make it clear to them also. Both RB's already have an electronic switch for each battery. They just need to add an user option to activate it. I am working on it though......
Dec 15, 2016, 03:19 PM
Registered User
Quote:
Originally Posted by Tadango
If a servo is jammed like this it should be cut off, at least in my planes.
The specs says above 5A the output shuts down (depends on the temperature)
The videos are there to show that those servos are capable to draw such currents. I personally registered those currents during flight using a current sensor. ( snaps and pop tops)
I'd prefer to have a version without limiting current protection or at least raise it to 10A. And the switch of course!

I use this switch in all of my gassers and it is really nice, but is even better when everything is included inside the RB
http://www.boomarc.com/en/hidden-bal...-with-pin-flag
Last edited by Ciusna; Dec 15, 2016 at 03:26 PM.
Dec 15, 2016, 05:14 PM
FJH
FJH
Registered User
Hold a second before requesting more features, the RB10 is designed to be a low budget RB and under that aspect it shall be kept as simple as possible. More simplicity with less active electronic components always means more operation reliability. Maybe FrSky will also come up soon with a new RB with more chanels (16) and more features like onboad regulated power and also some magnetic switch and others. So let the RB10 be the low budget which at its price level has no competitor at all. You even cannot built your own one with the RB features at its price level. This RB10 is worth every penny.
Dec 15, 2016, 06:32 PM
Registered User
Is about the reasons to use a rb10 that Tadango posted . I just wanted to point that looks like the rb10 is not adecuate for high torque servos.

Hopefully Frsky will come up with a new model (v2) of the big RB with the swich. But please no regulators
Dec 16, 2016, 03:18 AM
FJH
FJH
Registered User
[QUOTE=Ciusna;36427734Hopefully Frsky will come up with a new model (v2) of the big RB with the swich. But please no regulators [/QUOTE]

No onboard power regulators I agree 100%, such can be easily added as external module.

But I may say that your high current demand is not for the majority of users, for whom this RB10 is planned, your required current demand is extraordinary. Most users will for sure be happy with the RB10 data. And ofcourse it's also a matter how long the servo demands that high current, if the demand is only for some seconds then most probably the protection will not be activated. That is why also manual specifies and requires that the connected power supply shall be good for at least 40 A. I think it has to be tested how much current a servo can demand for how long before the protection gets activated. And your referred CB200 specifies 15A continuous, same as RB10, but for 16 chanels, RB10 has 8 chanels. Impulswise RB10 needs to be tested still. let's wait and see.
Last edited by FJH; Dec 16, 2016 at 03:35 AM.


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