If you are a long time Frsky user, you probably recognize the word “ACCST” printed at the bottom left of the Taranis display. ACCST is a TX protocol and it will be soon be replaced by a new protocol – ACCESS.
What is ACCESS Protocol?
ACCESS stands for Advanced Communication Control, Elevated Spread Spectrum. It’s the RF protocol that carries the signal from the radio to the receiver, what I would normally call the air protocol or TX protocol.
The existing protocol is ACCST which has been around for more than 10 years, you can find the label at the bottom left of your Taranis X9D display. ACCESS is the upgrade of ACCST.
I will discuss the new features and performance improvements that ACCESS will bring to the table.
Performance improvements includes:
- Lower latency and higher baud rate
- Up to 24 full range channel support
One thing I am not sure about is, SBUS and FPort can only transmit 16 channels, so I am not sure if there will be changes to the receiver protocol as well to support the remaining eight extra channels. If so, let’s hope the extra channels doesn’t impact latency like SBUS does. Currently, if we are using SBUS, we tend to only use 8 channels due to the lower latency even though we have the choice to use 16 channels. So 24 channels is clearly not needed for flying quads, but lower latency is nice.
Wireless Binding and Firmware Updating
ACCESS allows you to bind and flash new receiver firmware wirelessly. I found this to be one of the most exciting new features. TBS has been doing this on the Crossfire for years and I am glad Frsky finally caught up! Frankly, currently flashing new receiver firmware to Frsky receivers is quite annoying, hopefully it would make it a lot easier with this wireless method.
ACCESS has more advanced encryption according to Frsky. It’s a good thing so that people are less likely to see your stick/switch position or take over control of your model during flight. Although that rarely happens so I am not super excited about this.
But it seems to me this is a move to make it harder for 3rd party to reverse engineer their protocol, so that no one else can make receiver or transmitter module for Frsky’s product. Currently there are Frsky compatible (ACCST) receivers and transmitter modules made and sold by other companies, and they are keeping the price down. Maybe Frsky doesn’t want that so they are inventing a new protocol and put encryption on it. Just a guess.
Backward Hardware Compatibility
As far as I know, ACCESS will be supported on most of the current Frsky receivers and transmitters, so hopefully you won’t have to buy new hardware in order to enjoy the new protocol and features.
Where to Get ACCESS?
ACCESS will be first come with Frsky’s new radio, the Taranis X9 Lite. It will be made available for existing radios in the form of firmware update later hopefully. I am glad Frsky is making this possible for existing customers and not forcing them to buy brand new gear.
ACCESS firmware for receivers are already available for download on Frsky’s website, but only for five receivers at the time of publishing (May 2019): RXSR, RX6R, RX4R, G-RX6 and G-RX8.
For more info: https://www.frsky-rc.com/frsky-advanced-communication-control-elevated-spread-spectrum-access-protocol-release/
Am I Going to Try It?
Maybe, but not right now.
First of all, I have no plan of reviewing the X9 Lite, and I have no idea when it will be made available on the Taranis X9D.
Secondly, being new technology there will be bugs. I will probably wait until most of the bugs are ironed out.
It’s great that Frsky is finally improving their technology to catch up with TBS! And this will also make them more competitive against other players like Jumpers.