European DCC (NEM) compared to US DCC (NMRA)

NEM standards are the standards for model railroads issued by the MOROP. NEM stands for Normen Europäischer Modellbahnen (German) or Normes Européennes de Modélisme (French), which translates to European standards for model railroads.

The NEM standards cover areas similar to the standards and recommended practices defined by the NMRA in North America, but the two standards are not universally interchangeable. MOROP and NMRA have worked more closely together in recent years to establish common standards for developments such as Digital Command Control. European model railroad manufacturers follow the NEM standards, while North American manufacturers follow NMRA standards.

The NEM standards are defined and maintained by the Technical Commission of the MOROP in collaboration with model railroad manufacturers.

The NEM standards define the model railroad scales, guide manufacturers in creating compatible products, and assist modelers in constructing reliable model railroad layouts. The standards cover areas like suggested gradients, turn radii, wheel profiles, coupling designs, and Digital Command Control and are mostly scale-specific. A fundamental principle in NEM standards is compromises in the exact scale reduction ratio to favor the operational reliability of model railroad systems. An example is wheel flanges, which tend to be proportionally wider on the smaller scales to ensure a reliable operation.

DCC is an acronym that identifies the Digital Command Control Standard created by the National Model Railroad Association.

The NMRA decided that a standard was needed in the command control arena. So, committees were created, and discussions were held, eventually resulting in a proposed standard for command control. The NMRA Working Group decided that Digital technology was the way to go and built their standard around digital technology. Previous command control systems were built around analog technology, with some systems built around digital technologies.

Prior to the introduction of the NMRA DCC Standard, the market was fragmented into several completely incompatible command-control systems. See DCC History for more background.

The NMRA working group members offered their time and knowledge to create this and other standards so that everyone, from you to the manufacturer, will benefit, and the hobby will also benefit from these efforts. Not only did they ask modelers what they wanted, but they also took input from manufacturers in the model railroading industry, from small companies to large ones.

Using NMRA Digital Command Control, you are assured that any DCC-branded product should work with any other DCC-branded product. Those products will have the NMRA DCC Logo seen at the top of the page.