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

Document Posted Comments End
S-9.1 DCC Electrical Standard 18-Dec-24 24-Jan-25
S-9.3.2 BiDirectional Communication 03-Jan-21 Not Set
S-9.2.1.1 Advanced Extended Packet Format 23-Jun-24 Not Set
S-9.2.2 Configuration Variables 08-Jun-24 Not Set
S-9.4.1 SUSI proposed Standard 09-Jun-24 Not Set

Documents released for voting to approve by the DCC Working Group

Document Posted Voting Ends
No documents in voting period    

Documents approved and Released for  NMRA Membership review and comment.

Document Associated Posted Comments End
S-9 Electrical   12-Dec-2024 12-Jan-2024
RP-9 Electrical   23-Dec-2024 23-Jan-2025
Summary of Changes to LCC Documents      
Summary of Changes to LCC Documents  (extra comments)    
  TN-9.7.0.1 Glossary     
  TN-9.7.0.2  Common Information    
S-9.7.0.3 Unique Identifiers TN-9.7.0.3 Unique Identifiers 23-Oct-2024 31-Dec-2024
S-0.7.0.4 Event Indentifiers TN-9.7.0.4 Event Identifiers 23-Oct-2024 31-Dec-2024
S-9.7.1.1 CAN Physical Layer TN-9.7.1.1 CAN Physical Layer 23-Oct-2024 31-Dec-2024
S-9.7.2.1 CAN Frame Transfer Layer TN-9.7.2.1 CAN Transfer Layer 3-Oct-2024 31-Dec-2024
S-9.7.3 Message Network Layer TN-9.7.3 Message Network Layer 23-Oct-2024 31-Dec-2024
S-9.7.3.1 Event Transport Layer TN-9.7.3.1 Event Transport Layer 23-Oct-2024 31-Dec-2024
S-9.7.3.2 Datagram Transport Layer TN-9.7.3.2 Datangram Transport Layer 23-Oct-2024 31-Dec-2024
S-9.7.4.1 Configuration Description Information TN-9.7.4.1 Config Description Information 23-Oct-2024 31-Dec-2024
S-9.7.4.2 Memory Configuration TN-9.7.4.2 Memory Configuration 23-Oct-2024 31-Dec-2024
S-9.7.4.3 Simple Node Information Protocol TN-9.7.4.3 Simple Node Information Protocol 23-Oct-2024 31-Dec-2024
S-9.7.4.6 Train Control Protocol TN-9.7.4.6 Train Control Protocol 23-Oct-2024 31-Dec-2024
S-9.7.4.7 Train Search Protocol TN-9.7.4.7 Train Search Protocol 23-Oct-2024 31-Dec-2024
S-9.7.4.8 Function Description Information TN-9.7..4.8 Function Description Information 23-Oct-2024 31-Dec-2024

Documents to submit for Board of Directors Approval

Document Submitted Approved
S-9.2.1 DCC Extended Packet Format January 2025  

Previous document revisions were submitted to the Board of Directors and approved are now on the Standards page.

If you need additional information or wish to make further inquires regarding NMRA Standards, 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 23-Dec-2024 commeents/corrections: tech-elec [at] nmra.org (subject: nmra.org%3A%20Documents%20Under%20Revision%20Page)