DCC Web Resources

NMRA Standards and Recommended Practices

This project has benefitted from various web pages. The NMRA standards and recommended practices for DCC are the starting point for any DCC design. The DCC FAQ answers some basic questions about DCC. Of the relevant NMRA DCC documents, S-9.1 describes the electrical signal, S-9.2 describes the basic packet format, RP-9.2.1 describes the packet format for extended packets and RP-9.2.2 describes configuration variables. RP-9.1.1 describes the plug used for DCC inside locos and RP-9.2.4 describes fail-safe operation for command stations. RP-9.2.3 describes the service mode and RP-9.2.?(?) describes a protocol to interface to a computer but these are not yet finalised.

Other Standards

The Wangrow Interface Specification defines the protocol between a computer and an RS-232 capable command station. The X-Bus defines the protocol and other details of a bus to be used between several devices like cab control units, etc. Loconet is a proprietary system and not many details are available. The Silicon Junction DCC system does not use any of the above but will be based on the NMRA RP-9.2.?.

Other resources

Here are a list of resources that would be useful to hobbyists wanting to build their own DCC systems.

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Updated on 19 Feb 97. Feedback to