FrSky receiver feature chart

For posterity, some useful details to compare FrSky ACCST receivers. Last updated 26th March 2024.


  • This table lacks all of the Archer, Twin and Tandem range of ACCESS receivers.
  • It also lacks information about which receivers support F.Port (either with additional physical pins or firmware)

If you can help, let me know.

Receiver PWM Servo outputs Range Protocol Telemetry Configurable Failsafe Combined output RSSI out Analog 1 input Analog 2 input Digital telemetry input High Speed Servos Redundancy
V8R4-II 4 1km V8/D8 no yes no no N/A N/A N/A no no
V8R7-II 8 1.5km V8/D8 no yes no no N/A N/A N/A no no
V8R7-SP 7 1.5km V8 no yes CPPM (8) no N/A N/A N/A no no
VD5M 5 (micro) 300m V8/D8 no no no no N/A N/A N/A no no
V8FR-II 8 1.5km V8/D8 no yes no no N/A N/A N/A no no
D4R-II 4 1.5km D8 yes yes CPPM (8) yes internal voltage yes Hub Protocol no no
D6FR 6 1.5km D8 yes yes no no internal voltage yes no yes no
D8R-XP 8 1.5km D8 yes yes CPPM (8) yes yes yes Hub Protocol yes no
D8R-II Plus 8 1.5km D8 yes yes no no yes yes Hub Protocol yes no
X4R 4 1.5km D16 yes yes CPPM (8) yes internal voltage yes Smart Port no no
X4R-SB 3 1.5km D16 yes yes SBUS (16) yes internal voltage yes Smart Port no no
RX4R 4 2km D16 yes yes SBUS (16) yes (SBUS CH16) internal voltage yes Smart Port yes yes
X6R 6 1.5km D8/D16 yes yes SBUS (16) yes internal voltage / external analog no Smart Port no no
S6R 6 1.5km D8/D16 yes yes no yes internal voltage / external analog no Smart Port no no
RX6R 6 2km D16 yes yes SBUS (16) yes (SBUS CH16) internal voltage yes Smart Port yes yes
X8R / S8R 8 1.5km D8/D16 yes yes SBUS (16) yes internal voltage no Smart Port no no
RX8R 8 1.5km D8/D16 yes yes SBUS (16) yes internal voltage no Smart Port no yes
RX8R PRO 8 1.5km D8/D16 yes yes SBUS (16) yes internal voltage no Smart Port yes yes
XSR / XSR-M 0 1.5km D16 yes yes SBUS (16) / CPPM (8) no internal voltage no Smart Port N/A no
R-XSR 0 1.5km D16 yes yes SBUS (16) / CPPM (8) no internal voltage no Smart Port N/A yes
G-RX6 6 2km D16 yes yes SBUS (16) no internal voltage yes Smart Port + integrated vario yes yes
G-RX8 8 1.5km D16 yes yes SBUS (16) no internal voltage yes Smart Port + integrated vario yes yes
L9R 9 3km LR12 no yes SBUS (12) yes N/A N/A N/A no no
XM 0 600m D16 no yes SBUS (15) yes N/A N/A N/A N/A no
XM+ 0 1.5km D16 no yes SBUS (15) yes N/A N/A N/A N/A no
XMR 6 300m D16 no yes no no N/A N/A N/A no no
R9 8 10km R9 yes on Tx SBUS (16) yes internal voltage no Smart Port no yes
R9 slim / slim+ 6 10km R9 yes on Tx SBUS (16) yes internal voltage no Smart Port no yes
R9 mini / MX 4 10km R9 yes on Tx SBUS (16) yes (SBUS CH16) internal voltage no Smart Port no yes

Transmission Modes

There are five transmission modes of FrSky receivers, from oldest to newest:

  • ACCST V8 - non-telemetry channel-hopping, upto 8 channels.
  • ACCST D (D8) - stands for "duplex" (meaning two-way). The protocol supports telemetry, and upto 8 channels. Note that the "V*-II" generation of receivers can use this protocol, but do not support telemetry.
  • ACCST X (D16)- uses a more advanced way of communicating between the radio and the receiver (PXX). Supports upto 16 channels and telemetry.
  • ACCST L (LR12) - long range, no telemetry, uses PXX modulation, upto 12 channels.
  • R9 - long range over 900 Mhz, no telemetry, uses PXX modulation, upto 12 channels. Only compatible with specific transmitter
  • ACCESS - a closed-source encrypted protocol with both 2.4 GHz and 900 MHz variants, upto 24 channels and features such as OTA updates and automatic rebind


The "V8", "L" and "XM" series of receivers do not support telemetry - they lack an RF transmitter to send data back to your radio. The "D" and "X" receivers all support transmission of "received signal strength" (RSSI), but support three different methods of connecting sensors to report other information:

  • Analog: Up to 2 analog input ports (A1 and A2) for simple voltage-based sensors. Some receivers have A1 internally connected to measure the receiver's voltage, with A2 open for external sensors (e.g. for flight battery voltage).
  • Digital: The digital port on D-series receivers allows connection of more complex sensors such as a variometer. Multiple sensors can be connected via a hub.
  • Smart Port (S.Port): This newer mechanism on X-series receivers uses a full-duplex (two way) digital serial communication over a single signal wire. Sensors can be chained together and a hub is not required.


All models with telemetry will report the Received Signal Strength Indicator (RSSI) to your transmitter. However some receivers can output it through a servo channel, i.e. either a physical PWM output or an SBUS channel (see the manual). This generally means sacrificing a channel or some other function of the receiver, but is particularly useful for FPV pilots. The RSSI signal strength is sent to a flight controller so that it can be embedded alongside other telemetry in an on-screen video overlay that is transmitted back to the pilot's goggles/screen.

Control Outputs

There are two main ways of getting a control signal out of the receiver and to your flight controller, ESC or servos:

  1. Receivers designed for use in traditional aircraft without a flight control have PWM servo outputs, each with 3 pins (signal, V+ and V-)
  2. Many receivers, both with and without PWM outputs, can also output a digital signal.

There are via a few different protocols for digital outputs (intended for flight controllers, stabilisation systems etc):

  • The V8 and D generation receivers both use PPM modulation, which can carry upto 8 channels. Some receivers can output a combined CPPM signal on a 3-pin connector (either dedicated or one of the servo outputs), which is basically a sequential ordering of the raw PPM data.
  • The X generation receivers can use PXX, which has upto 16 channels, lower latency and features such as ModelMatch. Most of these receivers can output combined channels via the Futaba SBUS protocol, normally via a dedicated output. A few are switchable to CPPM too.
  • Later ARCHER receivers support F.Port, which functionally replaces both S.Port and SBUS for both telemetry and controls on a single wire.

A note regarding SBUS: it can be a source of great confusion that receivers and flight controllers describe "inverted" SBUS signals, with some hardware and software offering a way to switch between them. This phenomenon originates because the original Futaba implementation is based on the RS232 (UART) protocol but with some changes, one of which was to invert the signal (i.e. positive voltage is 0 and ground is 1). Since a lot of microcontrollers used for flight controllers and receivers have hardware UART implementations, using one of these for SBUS means the signal will be inverted compared to SBUS, albeit 'right way round' for UART. Hence it's necessary to implement additional pre/post-processing software/hardware.

A note regarding F.Port: Unfortunately I have not had the time to update the table with which receivers support F.Port. Later receivers have dedicated F.Port pins in addition to S.Port and SBUS pins; others like the R-XSR have firmware updates available, but it also updates to ACCST v2, for which transmitters must also be updated. Unfortunately the two are incompatible - updating the transmitter breaks compatibility with any older ACCST receivers.


The 'R' range of X series receivers (R-XSR, RX6R, RX8R, RX8R PRO, G-RX6, G-RX8, R9, R9 slim) feature a redundancy option.

High Speed servos

Some D-series and X-series receivers have an option for a faster update rate from their PWM servo ports. This is 9ms, compared to the default 18ms.


The S6R and S8R receivers add a 3-axis stabilisation feature to the X6R and X8R respectively.


The G-RX* range are designed for gliders and have an integrated variometer.

FASST receivers

I haven't collated the features for the TF range of FASST receivers but may do in future. Feel free to send me a list of the stats and I'd be happy to add them.



Nice sum up of all the FrSky Tx features. Cheers!

To the author, I generally don't comment however this is such a nice compliation, I had to compliment. 



Thank you. I haven't been following FrSky developments in the last year or two but if anyone has the info to update the chart with any new receivers I'd be glad to include them.

This post is just what I was looking for nice job The only question I still have is where the XSR would fit in to this as compared to the X8R?

The chart is very useful for FrSky freak. I bought one FrSky Taranis after comparing the FrSky with the help of your chart. Thanks a lot.

Need a update with all the new Rx's.

I am not familiar with anything released in the last few years so if you can compile the info I'd be glad to update it.

Great work ! Thank you. Saved me a lot of time.

Just come across this really handy page, This is a nice piece of work & will come in very handy as these receivers work there way onto the second hand market .... just what I was looking for.....



Thanku soo much.....

Very helpfull


Missing RX6R 

Added RX6R and RX4R

Also R9 mini, appears to be a new item

Great list, thanks. Missing G-RX6 now. Also, I understand S6R lacks SBUS output, unlike X6R, S8R and X8R.

Good call on the S6R, I was looking at the image of the S8R in the S6R I think. Have corrected. If you can gather the defials for missing ones I will add them but I have lacked time a bit lately to keep on top of it and RC is taking a back seat at the moment.

This list is absolutely fanstastic - very thorough and easy to navigate, well done, thanks heaps!

Great list, especially since the alternative site you linked to apparently is down.

Information for G-RX6:

Range for G-RX6 is specified to be > 2 km.  It has 6 PWM servo output, copared to 8 for the G-RX8.  Otherwise they seem to be identical, based on the link above.

Thanks, have added it.

What a cool page. This page out-lived the link you mentioned in your text. Too bad FrSky doesnt have a page like this.

Is it possible to add the weight?  I dont mind doing this for you, how can I give you the new column?

Sure, if you post a list in the same order they are in the table I can add them. Either as a comment or via the contact form.

I want to know if V8FR-II can be updated on his firmware to EU LBT ?

tks reply assistance.

I don't know, I would check if there is such a firmware on the FrSky website first.

Very helpful chart. I would remove the reference to the eflightwiki site. It is a commecial placeholder now.

Thanks for letting me know - done!

Great page but as a newbie, I can't figure out how to get the information on quality signal (RSSI) on G-RX6.

In your chart , G-RX6 doesn't support RSSI !              How can I have RSSI and variometer together?

G-RX6 specifications says: "Operating Current: 100mA@5V " .            Is this operating current reduced with no SBUS usage?

Thanks for any explanation.

Why G-RX6 indicated RSSI out : No while RX6R indicated RSSI out : Yes.

Could you explain if I can have both RSSI and variometer with G-RX6 without using sbus port ? ( I don't want to solder it !!! )

Thanks for this chart!

RSSI refers to output of the received signal strength locally within the model. I am going by the manual, which says that on the RX6R you can enable RSSI on channel 16 (i.e. SBus) by holding down the button for 5 seconds. On the G-RX6, I believe doing the same toggles the variometer on and off instead, which is probably the reason they don't mention RSSI in the manual at all. I don't believe either of them will output RSSI via the PWM outputs, the manual doesnt mention it, but I don't have either so can't say for sure.

All the telemetry receivers should transmit RSSI back to the transmitter via telemetry though. So just buy the G-RX6 for the vario and use telemetry on the radio for both vario and RSSI indication.

Огромное спасибо за отличную помощь и огрмную работу!!!


Great information - thanks 

Can any FrSky receivers support digital servos?


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