SOSS Documentation

eProsima

SOSS is a System-Of-Systems Synthesizer that allows communication among an arbitrary number of protocols that speak different languages.

If one has a number of complex systems and wills to combine them to create a larger, even more complex system, SOSS can act as an intermediate message-passing tool that, by speaking a common language, centralizes and mediates the integration.

The communication between the different protocols is made possible by system-specific plugins, or System-Handles. These provide the necessary conversion between the target protocols and the specific language spoken by SOSS. Once a system is communicated with SOSS, it enters the SOSS world and can straightforwardly reach out to any other system that already exists in this world.

SOSS is configured by means of a YAML text file, through which the user can provide a mapping between the topics and services on the middlewares of the systems involved.

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Main Features

SOSS provides a plugin-based platform that is easily and intuitively configurable. This section explains these key features.

System Handles

A SOSS instance can connect N middlewares through dedicated plugins that speak the same language as the core. This common language is eProsima xtypes; a fast and lightweight OMG DDS-XTYPES standard C++11 header-only implementation. The plugins, or System-Handles, are discovered by SOSS at runtime after they have been installed.

Built-in System-Handles are provided for the following systems: DDS, Orion ContextBroker, ROS, ROS2, and WebSocket. New System-Handles for additional protocols can be easily created, automatically allowing communication of the new protocol with the middlewares that are already supported. Detailed information on how to create a System-Handle can be found in the System-Handle Creation section of this documentation.

The plugin-based framework is especially advantageous when it comes to integrating a new component into a complex system where the rest of sub-systems use incompatible protocols. Indeed, once all protocols of interest are communicated with SOSS, each via a dedicated System-Handle, the integration is mediated by the core and relies on centralization rather than on the creation of dedicated bridges for each pair of components. For a system made of N components, this means that the number of new software parts to add grows as N rather than .

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YAML configuration files

SOSS is configured by means of a YAML file. Detailed information on how to configure a SOSS-mediated communication by means of one such file can be found in the YAML Configuration section of this documentation. Notice that a single YAML file is needed no matter how many protocols are being communicated.

Below you can find a minimal example of the information that this configuration text file should contain. In this example, a single topic is translated from ROS1 to ROS2:

systems:
    ros1: { type: ros1 }
    ros2: { type: ros2 }
topics:
    chatter: { type: std_msgs/String, route: {from: ros1, to: ros2} }

The strength of this approach is that different translations are possible by only changing the configuration file. For example, by changing the middlewares involved, we can obtain an instance which translates between WebSocket+JSON (as produced and consumed by a standard Web browser) and ROS2:

systems:
    web: { type: websocket_client, types-from: robot, host: localhost, port: 12345 }
    robot: { type: ros2 }
routes:
    web2robot: {from: web, to: robot}
topics:
    chatter: { type: "std_msgs/String", route: web2robot }

Additional features

Free and Open Source.

SOSS and all System-Handles available to date are free and open source.

Easily configurable.

As detailed above, a SOSS instance is easily configurable by means of a YAML file.

Easy to extend to new platforms.

New platforms can easily enter the SOSS world by generating the plugin, or System-Handle needed by the core to integrate them.

Easy to use.

Installing and running SOSS is intuitive and straightforward. Please refer to the Getting Started section to be guided through the installation process.

Commercial support.

Available at support@eprosima.com

Structure of the Documentation

This documentation is organized into the following sections.

Installation Manual

This section is meant to provide the user with an easy-to-use installation guide and is organized as follows:

User Manual

This section provides the user with an in-depth knowledge of SOSS’ main aspects. First of all, we detail the internal structure of a System-Handle and guide the user through the creation a brand-new System-Handle. Secondly, we explain how to configure SOSS by means of YAML files, explaining how to fill the required fields, depending on the needs of the specific use-case.