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Thank you for your interest in the NMRA's Digital Command Control (DCC) Standards and Recommended Practices. This page contains links to the current approved copies of the Standards & Recommended Practices (RPs).
Please note that when both PDF and HTML versions are provided, the PDF version is the definitive one.
| Standard S-9.1 | DCC Electrical Standard | July 2004 | N/A | |
| Standard S-9.2 | DCC Communications Standard | July 2004 | N/A | |
| Recommended Practice RP-9.1.1 | DCC Electrical Interface & Wire Color Code | Jan 2008 | ||
| Recommended Practice RP-9.1.2 | DCC Power Station Interface | July 2003 | ||
| Recommended Practice RP-9.2.1 | DCC Extended Packet Format | Jan 2006 | ||
| Recommended Practice RP-9.2.2 | DCC Configuration Variables | July 2007 | ||
| RP-9.2.2 Appendix A | Manufacturer ID codes | June 2008 | N/A | |
| Recommended Practice RP-9.2.3 | DCC Service Mode | January 2006 | ||
| Recommended Practice RP-9.2.4 | DCC Fail-Safe | March 1997 | ||
| Recommended Practice
RP-9.3.1 |
DCC Electrical Specifications for Decoder Transmission | Jan 2007 | N/A | |
| Recommended Practice RP-9.3.2 Draft form, but mfg should use this RP |
DCC Basic Decoder Transmission | April 2005 | N/A |
DCC involves technical information that doesn't always fit in the categories of Standards, Recommended Practices or Technical Notes. Informally, we call this "Technical Information".
These documents supersede all previous versions.
If you need additional information or wish to make further inquires regarding NMRA DCC, please contact the NMRA DCC Working Group or the NMRA Staandards & Conformance Department. The NMRA DCC Working Group can be contacted at: tech-dcc@hq.nmra.org
DCC (Stds) Manager
National Model Railroad Association
Department #635
4121 Cromwell Road, Chattanooga, TN 37421
Phone +1.423.892.2846 Fax +1.423.899.4869