Originally Posted by: intruder 
Can someone please explain to me what the major difference between mfx an d DCC is?
Hi Svein,
Perhaps I can help with a very simplified explanation, as I understand it. I am not a digital expert and don't really know or want to know the fine detail of the protocols.
The original digital standards for control of model railways was developed by Lenz in conjunction with Marklin. Both the original Marklin digital format and DCC are developments of Lenz's protocol. Marklin's circuits were produced by Motorola, hence the use of the term Marklin Motorola, or MM for this system. Electronically, both digital signals are similar.
Marklin's original system was developed after about 10 years into the MM2 format, which allowed more functions. These were labelled by Marklin as being "FX" decoders.
In contrast, DCC was continuously developed over the years to the standard we see today. This is because the protocols are open for anyone to use, so many small companies produced improvements. It overtook the capabilities of Marklin's system to provide a greater number of addresses, functions, etc.
In the Early 2000's Marklin needed a way to improve the digital product and, if possible, leapfrog the capabilities offered by the cometitior DCC system. Together with ESU they developed the MFX system, which offered greater numbers of functions, virtually unlimited addresses, and for the first time the ability of locomotives to register themselves on the controller, which meant that the operator did not need to remember the locomotives address, or what functions were available, as these were displayed on the screen after automatic registration.
ESU and Marklin fell out over the development of the system. I won't go into detail why, but I believe no one party was at fault. There were shortcomings on both sides of the partnership. Marklin retained the rights to MFX and used other companies to produce the hardware needed to continue the system. ESU retained the right to use the MFX protocol in their decoders and controllers.
Developers of DCC then saw that the auto-registration features of MFX were a serious advance from their competitors, so they also developed a similar system, which was named Railcom. The way the similar functionality is derived is, I believe, completely different to how ESU developed the MFX system for Marklin.
The position as it stands today is that we have Marklins (and ESUs) MFX system, with auto-registration, about 16 or so functions, and unlimited addresses which are invisible to the user.
On the other side we have the DCC standard, which now also has Railcom's auto-registration, though this is not available in all controllers. DCC has a greater number of functions (about 25?), and virtually unlimited addresses, though these have to be specified to the controller.
My feeling is, and I don't have any numbers to prove it, that traditional Marklin users have adopted the MFX system in good numbers and welcome the increasing numbers of locomotives available to use with either their Central or mobile stations. DCC users, the majority of whom are from a 2-rail DC background, continue to use DCC as implimented in various brands of controller, but are probably slower on the uptake of Railcom compared to MFX users.
This post represents how I view the digital control story, and I may or may not be perfectly correct in any or all of my statements. It's just an attempt to answer Svein's question about the differences between MFX and DCC.