Definition of Terms

This page lays out a common terminology for discussing the components and underlying technologies used by the platform. The first section discusses capabilities and industry standards that VOLTTRON conforms to while the latter is specific to the VOLTTRON domain.

Industry Terms

Agent: Software which acts on behalf of a user to perform a set of tasks.
BACNet: Building Automation and Control network that leverages ASHRAE, ANSI, and IOS 16484-5 standard protocols
DNP3 (Distributed Network Protocol 3): Communications protocol used to coordinate processes in distributed automation systems
JSON (JavaScript Object Notation): JavaScript object notation is a text-based, human-readable, open data interchange format, similar to XML but less verbose
IEEE 2030.5: Utilities communication standard for managing energy demand and load (previously Smart Energy Profile version 2, SEP2)
JSON-RPC (JSON-Remote Procedure Call): JSON-encoded Remote Procedure Call
Modbus: Communications protocol for talking with industrial electronic devices
PLC (Programmable Logic Controller): Computer used in industrial applications to manage processes of groups of industrial devices
Python Virtual Environment: The Python-VENV library allows users to create a virtualized copy of the local environment. A virtual environment allows the user to isolate the dependencies for a project which helps prevent conflicts between dependencies across projects.
Publish/Subscribe: A message delivery pattern where senders (publishers) and receivers (subscribers) do not communicate directly nor necessarily have knowledge of each other, but instead exchange messages through an intermediary based on a mutual class or topic.

Note

The Publish/Subscribe paradigm is often notated as pub/sub in VOLTTRON documentation.
RabbitMQ: Open-Source message brokering system used by VOLTTRON for sending messages between services on the platform.
Remote Procedure Call: Protocol used to request services of another computer located elsewhere on the network or on a different network.
SSH: Secure Shell is a network protocol providing encryption and authentication of data using public-key cryptography.
SSL: Secure Sockets Layer is a technology for encryption and authentication of network traffic based on a chain of trust.
TLS: Transport Layer Security is the successor to SSL.
ZeroMQ: (also ØMQ) A library used for inter-process and inter-computer communication.

VOLTTRON Terms

Activated Environment

An activated environment is the environment a VOLTTRON instance is run in. The bootstrap process creates the environment from the shell.

AIP (Agent Instantiation and Packaging)

This is the module responsible for creating agent wheels, the agent execution environment and running agents. Found in the VOLTTRON repository in the volttron/platform directory.

Agent Framework

Framework which provides connectivity to the VOLTTRON platform and subsystems for software agents.

Bootstrap the Environment

The process by which an operating environment (activated environment) is produced. From the VOLTTRON_ROOT directory, executing python bootstrap.py will start the bootstrap process.

Config Store

Agent data store used by the platform for storing configuration files and automating the management of agent configuration

Driver

Module that implements communication paradigms of a device to provide an interface to devices for the VOLTTRON platform.

Driver Framework

Framework for implementing communication between the VOLTTRON platform and devices on the network (or a remote network)

Historian

Historians in VOLTTRON are special purpose agents for automatically collecting data from the platform message bus and storing in a persistent data store.

VIP

VOLTTRON Interconnect Protocol is a secure routing protocol that facilitates communications between agents, controllers, services, and the supervisory VOLTTRON_INSTANCE.

VIP address

Public address bound to by a VOLTTRON platform instance for communication (Example: tcp:///192.168.1.20:22916). Communication to external platform instances requires that the address be in range for external communication from the host.

VIP Identity

Unique identifier for an agent connected to an instance. Used for messaging, routing and security.

VOLTTRON Central

VOLTTRON Central (VC) is a special purpose agent for managing multiple platforms in a distributed VOLTTRON deployment

VOLTTRON_HOME

The location for a specific VOLTTRON_INSTANCE to store its specific information. There can be many VOLTTRON_HOME`s on a single computing resource such as a VM, machine, etc. Each `VOLTTRON_HOME will correspond to a single instance of VOLTTRON.

VOLTTRON_INSTANCE

A single VOLTTRON process executing instructions on a computing resource. For each VOLTTRON_INSTANCE, there WILL BE only one VOLTTRON_HOME associated with it. For a VOLTTRON_INSTANCE to participate outside its computing resource, it must be bound to an external IP address.

VOLTTRON_ROOT

The cloned directory from Github. When executing the command:

git clone https://github.com/VOLTTRON/volttron.git

the top level volttron folder is the VOLTTRON_ROOT.

Web Framework

Framework used by VOLTTRON agents to implement web services with HTTP and HTTPS