Table 1 – Terms


Definition of Term


Vision sensor that is capable of extracting information from electro-magnetic waves.


Receiver of information. Requests services from a server, usually OPC Machine Vision system.


Information stored in a configuration ensures that different vision systems generate equal results if same recipe is used.


The set of external entities working with the vision system in one way or another, e.g. PLC, MES, etc.


Not part of the vision system or the OPC UA server; may refer to the automation system, the manufacturing execution system or other entities


The main purpose of a machine vision system is to execute jobs. Job may be a simple task such as measurement of a part’s diameter, or much more complex, like surface inspection of a long, continuous roll of a printing paper.

Machine Vision System

A system for machine vision is any complex information processing system / smart camera / vision sensor / other component which, in the production context, is capable of extracting information from electro-magnetic waves in accordance with a given image processing task.

Inline Machine Vision System

Denotes a machine vision system which is used in the manner of a system working continuously within a production line (hence the name). This can mean 100% quality inspection, as well as providing poses for robot-guidance for all parts or inspection of the entire area of a continuous material stream and other similar use cases.


In an industrial environment a machine vision system is usually used to check products that are manufactured. The name of such a product is often used outside the machine vision system to reference recipes of the devices used to manufacture the product. This eliminates the need for the external production control systems to know the IDs of local recipes of each device.


Properties, procedures and parameters that describe a machine vision job for the vision system are stored in a recipe. The actual content of the data structure is out of the scope of this specification.


Information provider classified by the services it provides. Vision system commonly acts as OPC UA server.

State Machine

A finite-state machine (FSM) or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of states at any given time. The state machine can change from one state to another in response to some external inputs. The change from one state to another is called a transition. A state machine is defined by a list of its states, its initial state, and the conditions for each transition.

System-wide unique

Used in conjunction with identifiers and handles to denote that at any given time no other entity of the same type and meaning shall exist in the OPC UA server with the same value. No further assumptions about global or historical uniqueness are made; especially in the case of identifiers, however, globally unique identifiers are recommended.

Vision System

The underlying machine vision system for which the OPC UA server provides an abstracted view.


WebSocket is a computer communications protocol, providing full-duplex communication channels over a single TCP connection.