Documents Under Revision

NMRA Standards, RPs, TNs, TIs Under Revision

The NMRA, in its standards and recommended practices, addresses only the specific standards and recommended practices for model railroads.  These standards and recommended practices do not address any legal requirements.  It is the responsibility of the manufacturer to determine if their product conforms to all applicable governmental laws and regulations.

Documents released by the NMRA for review and comment 

Documents released for review and comment

S-9.3.2 BiDirectional Communication (1/3/21)
The comment period has not been set.

S-9.2.1 DCC Extended Packet Format (5/122023)
The comment period has not been set.

S-9.2.2 Configruation Variables (6/8/2023)
The comment period has not been set.

Documents released for voting to approve by the Working Group

There are currently no documents for voting.

Documents approved and Released for  NMRA Membership review and comment.

There are currently no documents for comment.

Documents to submit for Board of Director Approval

RP-2 Standard Gauges (15-Jan-2024) was approved by the board January 26, 2024

Previous document revisions were submitted to the Board of Directors and approved at their May 2022, August 2023 and January 26, 2024 meetings. These are now on the Standards page.

If you need additional information or wish to make further inquires regarding NMRA DCC, please contact the NMRA Standards & Conformance Department at tech-chair [at] nmra.org, CIManager [at] nmra.org or dcc-manager [at] nmra.org

National Model Railroad Association, Inc.
Department #635
P.O. Box 1328, Soddy Daisy TN 37384-1328
Phone: (423) 892-2846 - Fax: (423) 899-4869

Updated 06-Feb-2024