JMRI Hardware Support - Multiple Computers to LocoNet® via LbServer
Author: Bob Jacobsen
Keywords: Digitrax Chief DCS Command Station LocoNet Server LocoBuffer java model railroad JMRI install windows

# Hardware Support: Connecting Multiple Computers to LocoNet® via LbServer

This page describes how to configure multiple JMRI nodes to connect as clients to a single LocoNetOverTCP LbServer, which in turn is connected to the layout.

This connection, called LocoNetOverTCP, uses a separate non-Java server process, LbServer, that communicates using plain ASCII String messages over TCP/IP sockets, allowing non-Java nodes to also share the one LocoBuffer.

## Setup for JMRI LocoNetOverTCP

One computer runs the LbServer program that connects to the LocoBuffer and acts as a Server to all the JMRI Client computers. Configure the JMRI Client computers to connect to the LbServer as follows:

- Make sure the LbServer is configured and running. See LbServer documentations for details.
- Open the JMRI program on the Client
- Open the preferences from the Edit menu
- For layout connection, select "LocoNetOverTCP LbServer"
- In the "Server hostname" box that appears, type the Internet name or address of the computer that's running the LbServer. An internet address is something like 127.0.1.12; a name is something like jmri.org
- In the "TCP Port Number" box enter the port number that LbServer is using, which by default is 1234.
- Save the preferences and restart the program.

## Notes:

- It's strongly recommended that you connect the master computer to the LocoNet® with a LocoBuffer or LocoBuffer-II. Although a MS-100 will basically work for this application, correction of the resulting occasional LocoNet errors may cause noticeable delays in updating the remote computers.
- If the computers are all close to the LocoNet, e.g. acting as local control panels, you don't really need LocoNet Server to do this. You can instead connect each of the computers to the LocoNet via their own LocoBuffer or LocoBuffer-II (or MS-100, though this is not recommended) and have them individually take part in the LocoNet communications. This doesn't cause any additional communications load. It does cost a little more for the extra adapters, and doesn't permit you to put a computer remote from the layout.
- The computer running LbServer can also run JMRI software, in this case the Client and Server just happen to be on the same node.
- Some firewall software will detect LbServer's use of port 1234 as a trojan and will want to block access to the port. To get around this you will either have to enable access in your firewall software or change the port to another number like 9999 say. The new port number will also need to be passed into LbServer as a command line option.

LocoNet® is a registered trademark of Digitrax, Inc.