6 OPC UA Tightening System Information Model overview 
6.2 Asset Management
6.2.1 Assets
Assets are various components of a tightening system. This version of the specification describes the physical assets which are parts of the system that can contain a processor or electronically interact with a part containing a processor.
6.2.1.1 Overview
The assets are modelled using the generic object declaration BaseObjectType place holders to ensure interoperability from various other domain specifications.
This specification defines set of interfaces for each type of asset and asset instances can be implemented by including the required interfaces defined in this specification. The asset instances can also be modelled by external interfaces from other companion specifications or vendor specific extensions with the help of open generic model.
6.2.1.2 Controllers
0 This is a container for the set of controllers in a given system
A controller can represent an entity that can control an aspect of the joining process. A controller can also be any kind of supervisory instance, which manages multiple tools. So, controller can be any kind of computation device which controls specific parts of the tightening system and communicates to another system. A tightening system may consist of multiple controller instances. The first controller in the list is intended to harbour the OPC UA communication for the Tightening System information model.
6.2.1.3 Tools
0 This is a container for the set of tools in a given system
A tool (or spindle) represents a physical device that tightens a bolt. It can for example be held by a human being, attached to a robot, or be part of a multi-tool fixture.
A tool has usually a drive to perform the tightening operation. There may also be some kind of sensors involved to get the process status.
Note: Spindle is a common term used in Fixtured system to represent a specific type of Tool.
6.2.1.4 Servos
0 This is a container for the set of servos in a given system
A servo amplifier represents a physical device that controls the motor in the tool. It is the physical power stage to deliver the power to the motor to perform the tightening or some other movement in the system.
6.2.1.5 MemoryDevices
0 This is a container for the set of memory devices in a given system
Those memory devices may be implemented for example like memory cards or memory modules. Those are used to store data also during the power off phase of the device.
A MemoryDevice (or Storage Device) stores data, such as, the system identity, the software of the system, licenses, tightening programs, etc.
6.2.1.6 Sensors
0 This is a container for the set of sensors whose measurements can be transformed and processed within a given system
Each sensor is responsible for one measurement signal. Therefore, it measures one quantity and delivers the value by doing so.
The sensor data may be used in the system to perform the tightening, but also can deliver other information of the system.
Besides the measured quantity the sensor may expose its calibration information, which may be useful for quality assessment.
6.2.1.7 Cables
0 This is a container for the set of cables in a given system
Cables are there to interconnect certain parts of the system. Example: Cable from a tool to a controller.
Note: For this version of the specification, Cables are only modelled in the system if the required information can be provided by the system.
6.2.1.8 Batteries
0 This is a container for the set of batteries in a given system
Note: For this version of the specification, Batteries are only modelled in the system if the required information can be provided by the system.
6.2.1.9 PowerSupplies
0 This is a container for the set of power supplies in a given system. The power supplies typically deliver power to a servo or battery
6.2.1.10 Feeders
0 This is a container for the set of feeders in a given system
A feeder stocks the fasteners and separates the elements and makes them available at the joint position. A feeder may also content a controller for managing the operation sequence.
Examples: Bunker, bowl feeder, step feeder, etc.
6.2.1.11 Accessories
0 This is a container for the set of accessories in a given system
Accessories represents devices put on the tool or in the station to help the user understand and influence the tightening process.
Examples: Stack lights, socket selectors, screens, scanners, location tags, reaction bars, operator panel, etc.
Note: There are other specific companion specification for some accessories like Stack light, etc. and that model could be implemented in the current Accessory instance since all the assets are modelled as BaseObjectType placeholders.
6.2.1.12 SubComponents
0 This is a container for the list of subcomponents in a given system
A subcomponent is a system-specific part that can be plug-in or permanently installed and enables the tightening system to perform a specific task.
Examples: Radio modules, fieldbus modules, software modules etc.