DSM2 "Security Features" supported?

Hi guys,

first of all: this community is my new personal mekka. So glad I found it. Can't wait to get my devo7e, haha.

A question that came up while looking into this: Can I expect the devo to work exactly as my original spektrum-module right now? Asking especially for the "security mumbo jumbo" that spektrum claims to have with their equipment:
www.spektrumrc.com/Technology/DSM2.aspx

THE SIGNAL SECURITY OF DUALLINK™
In aircraft transmitters, DSM2 uses DuaLink™ technology to ensure a superior RF link between you and your model. When a DSM2-equipped aircraft transmitter is switched on, DualLink scans for two free channels in the 2.4GHz band. When it finds them, the DSM2 aircraft receiver, which "listens" for its transmitter's distinct GUID, will lock on to two free channels. And because the coding gain of a DSM2 wideband signal allows it to be "heard" above the 2.4GHz noise in typical RC environments, you will enjoy a solid connection and outstanding precision even without frequency shifts. In fact, for many modelers, DSM2 will continue to provide all the speed and precision they'll ever want long after future versions of DSM technology are developed.

Is this "frequency hopping" supported as well with deviation?

Thank you!

Yes. Wouldn't work otherwise. DSMX does it better, as it uses more than two channels after the initial connection. In fact, it's now illegal to sell DSM2 Rx's in the EU, as the 2-channel behavior is considered sufficiently unfriendly to other spread-spectrum radios.

The marketing speak "Dual-Link" sounds soo good. But the technology is outdated and poor by today's standard.

Daryoon wrote: The marketing speak "Dual-Link" sounds soo good. But the technology is outdated and poor by today's standard.

Even Spektrum would agree with that. He's quoting from a blurb on DSM2. I don't know think any of the DSM2-only spektrum gear is still in production. They've moved on to DSMX, and I don't recall seeing them touting "dual link" for any of the DSMX gear. On the other hand, everybody does it, and you no longer need to explain to people at the field why your funny Tx with the stubby little antenna doesn't need a frequency pin.

Hi! Good to know that the security-voodoo is pretty much a given that comes with the technology itself.
Thank you guys!

mwm wrote: In fact, it's now illegal to sell DSM2 Rx's in the EU

To be more precise: it's in fact legal to sell those when produced before 2015, but it's now (since 01/2015) illegal to introduce newly produced DSM2 transmitters (probably also applies to receivers, with transmitters it's definitely true) into the market. It's absolutely legal to continue using DSM2 products, it's also legal to sell used DSM2 equipment.

What I don't know: is it legal limbo to install deviationTX on newly produced Devo transmitters and use it for DSM2 gear? Does anybody know?

Without a proper "declaration of conformity" which puts your transmitter according to ETSI 1.7.1 into the specified class, probably not?

Spektrum has the proper KE for its older transmitters for DSM2 in their manuals.

Not sure if they use 10mw or 100mw output power on their DSM2 for their "channel hopping system" according to ETSI 1.7.1.

Walkera Devos do not have the KEs, even for DSM2 + 10mw?!?

I had one thread posted on RC-Network.de asking if DEVO protocol >10mw would be even allowed. I got not the (technical) answer I was hoping for.


But why would one jump from DEVO protocol (3 channel DSSS) to a 2 channel DSSS DSM2 protocol?
Well sure, with the GY280RX you have to But most modern receivers are on DSMx.

Thomas

@Thomas, here in Germany I have asked our "Bundesnetzagentur" if the devo protocol is legal to be used with more than 10mW. I got an answer: yes, it is. DSSS underlies the same restrictions as WLAN, means: if the signal is spread wide enough to ensure transmission power is restricted to 10mW per 1MHz bandwidth, you are allowed to use it up to 100mW total output. According to the devo protocol is definitely legal to be used at 33mW, at least, and 33mW is a possible setting in the original Walkera devo firmwares. I do not have any option to measure this by myself, but I think it's even legal to use 100mW, which I would recommend for 450 sized helicopters.