I notice on the Deltang site that the Rx-60 etc etc are marked as compatible with DSM2/DSMX.
Does this mean that if the RX is bound to a DSMX transmitter it automatically uses the more sophisticated multiple frequency hopping protocol of DSMX rather than the simpler 2 frequency protocol of DSM2?
DSMX is the true evolution from DSM2 and this system is backward and forward compatible to DSM2.
Any DSM2 receiver works with a DSMX transmitter and any DSM2 transmitter works with a DSMX receiver.
So it is just the choice of channels that makes the difference.
Helmut wrote: DSMX is the true evolution from DSM2 and this system is backward and forward compatible to DSM2. Any DSM2 receiver works with a DSMX transmitter and any DSM2 transmitter works with a DSMX receiver. So it is just the choice of channels that makes the difference.
I am still confused.
As I understand it a DSM2 transmitter when switched on chooses 2 frequencies within the 2.4 Ghz band and can hop between these frequencies.
When a Rx bound to that transmitter switches on it receives and uses those frequencies as part of the handshake data package that the Tx is transmitting?
A DSMX Tx uses many more frequencies which it cycles through in a semi random manner and a Rx bound to it follows the 'random' sequence given to it by the Rx?
My question is, does a Deltang Rx which is DSMX compatible use that multiple 'random' frequency hopping and timing if bound to a DSMX transmitter and benefits from the enhanced signal security that DSMX offers?
Or does it just take 2 frequencies and use those?
In the absence of a translation in English of this statement by a Spektrum representative, I can only speculate Tx/Rx performance is better. I believe DavidT once told me DSM2 was more than adequate for model railroading.
I do use a Spektrum DX5e Tx with DSMX protocol with my DelTang equipped locos at shows to avoid interference with other control systems, which I have never had. There is a topic covering interference on this website.
Last edited on Sat Oct 6th, 2018 04:49 am by dan3192
As I understand it, the difference between DSM2 and DSMX is correct - DSM2 can use two frequencies, DSMX uses more.
As Helmut says, the two are compatible and the Rx/Tx pair will use the higher spec DSMX if it can, and DSM2 if one or both does not use DSMX. So a DSMX Rx will work with DSMX if the Tx has this capability, and DSM2 otherwise, as you surmise.
However, both use a "Spread Spectrum" signal which does not in fact use a single frequency for the data but spreads it over a band of frequencies. This gives the biggest part of the interference protection, and both use it.
Thanks folks, I think I understand it now. It appears DSM2 is perfectly suitable for the vast majority of model railroaders so no need to worry. I am not going to be exhibiting a layout at a very large exhibition anytime soon.
DSM2 is even in a crowded environment very interference-proof. I regularily use up to 5 RC locos with DT equipment within a radius of ~100ft ( Don't drive them all myself, mind you, I just provide them ), and all that in close vicinity to a WLAN-based comms system we use for train scheduling at meetings, where the clients are set some 30ft apart . I have yet to experience loss of control.