DCCWiki, a community DCC encyclopedia.
Jump to: navigation, search

Summary: LocoBuffer-USB / LocoBuffer-NG provides a simple and easy way to create a bridge/connect between a computer's Universal Serial Bus (USB) and Digitrax's Loconet

The LocoBuffer-USB is manufactured by RR-Cirkits. The earlier LocoBuffer II used a serial interface port instead of the USB port.

LocoBuffer-USB Features

  • USB 2.0 to Loconet® interface
  • Optical isolation between USB and LocoNet® prevents potential grounding problems
  • Buffered inputs and outputs allows use with all USB supported operating systems
    • CD with drivers for Linux 2.4, Mac OS-9, OS X, MacOS, MS Windows 98SE, ME, 2K, XP
  • Packaged unit size just 1-1/2" x 3" x 3/4"
  • Ready to run
  • Internal LocoNet® terminator.
    • Allows a LocoBuffer-USB to add LocoNet® device compatibility to other systems
  • 57,600 BPS interface speed
    • No jumpers or switches to set
  • Compatible with existing software
  • Installs as a serial port
  • Hardware handshaking using RTS/CTS
    • Includes DTR/DSR turn back required for MS Windows XP
  • Boot Loader for firmware upgrades
    • Does not require special hardware to install upgrades
  • Powered directly from USB and LocoNet® Rail Sync lines
    • No external power adapter needed
  • Internal option connector allows for future features
    • Planned optional programming track output
  • Includes 3' USB A-B and 14' LocoNet® cables


This device allows you to connect the layout's LocoNet to a computer, and using software, automate or configure various things. One application is using DecoderPro from the JMRI webpage to program your decoders.

Instead of the labourious task of programming a decoder manually, you can do it with a graphical interface on your computer. Or even save the config before tampering with the settings. Especially useful if you have a sound decoder that has a million options.


Serial to USB note

The device needs the RTS/CTS signals to work. If you need a serial-USB converter, some may not work as they ignore the RTS and CTS lines on the serial port. See the JMRI web site for info.

JMRI Version 4.16 Issues

JMRI version 4.16 has an issue which, in some cases, disables operation of the LocoBuffer-USB.

The only known solution to this bug is to upgrade JMRI to the 4.17 (test version) or higher/

Microsoft Windows 10

Updated drivers are required for Microsoft's Windows 10.

Instructions are here at the RR-Cirkits website: Windows 10 Driver install for LocoBuffer-USB


The LocoBuffer-NG is similar to the LocoBuffer-USB, except it looks like a USB thumb drive. It plugs directly into the computer (USB Type A connection) and has an RJ12 jack for connection to LocoNet.

  • Three status LEDs
  • Plug and Play, no settings required
  • 15kV isolation between computer and LocoNet
  • Operating Systems Compatibility: MacOS, Linux and Windows
  • Small package: 2 × 1 × ⅝"

May require an optional USB Type C to Type A cable.

See also


  1. RR-CirKits, Inc. LocoBuffer-USB User's Guide, pg. 1