Overview

SSH and SFTP

Clearpath robots ship with an SSH server operating on port 22 for remote login. This server also supports sftp for file-transfer to/from the robot if needed. By default you can log in using the default username and password for the robot.

Wired LAN IP Addresses

All Clearpath robots use the 192.168.131.0/24 subnet for any permanently-installed network hardware. This includes, but may not be limited to

• the robot's primary computer,
• the robot's MCU,
• a secondary computer (if present),
• any cameras, lidar, or other sensors that communicate over Ethernet, and
• any long-range wireless radios.

The 192.168.131.0/24 subnet is statically configured; all devices are configured to use a static IP address, and there is normally not a DHCP server operating on this subnet.

For a list of standard payload IP addresses, please see network IP addresses.

ROS 2 Networking

ROS 2 networking uses an abstracted middleware referred to as the "RMW Implementation". The Clearpath robot packages support eProsima Fast DDS as the middleware implementation. This middleware has two supported options for ROS 2 node discovery, Simple Discovery and Discovery Server. Each of these discovery mechanisms has their own use case:

Simple Discovery

• Default, does not require manual setup
• Generally operates on the basis that any ROS 2 devices on the network should be discoverable and connect automatically
• Requires multicasting on the network (may be restricted on school or corporate networks)
• Good for simple systems (small number of robots on a dedicated local network)

Discovery Server

• Requires manual configuration in the robot.yaml
• Generally operates on the basis that ROS 2 networks should be controlled and can only discover other devices as directed
• Does not require multicasting (more likely to work on school or corporate networks)

Further information on ROS 2 Networking.

tip

For the best chance of success, use a high speed, high bandwidth network and monitor the network usage.

Clock Synchronization

If your robot contains multiple computers, their clocks must remain synchronized to allow proper communication between ROS nodes running on each one. Clearpath configures the computers to use chrony to synchronize the clocks, with the primary computer being the authoritative source for the others.

For details on configuring chrony, please see configuring NTP.

note

Contact our Support team at support@clearpathrobotics.com if you have any questions.