Talk:BaSyx / Documentation / API / ControlComponent

Control component interface harmonization

Lets try to harmonize existing implementations of control components and sync to the control component profiles, which are used to test conformance. The following changes to the VAB implmentation documentation of control components are suggested

• Delete 'service' path segment for list of operations
• Use uppercase paths to distinguish between user specific and standardized elements.
• Focus on the OPERATIONS profile as minimum requirement.
• Focus on 'mandatory' attributes
• Delete signals for localOverwrite and localOverwriteFree as they are technology specific and should be 'hard wired'.
• Use network layer authorization to occupy component (no senderId parameter for operations, otherwise all operations need a senderId parameter)
• OPC UA mapping:
  • Delete Control path segment for the OPC UA browse path
  • Add a namespace for basys that can be used to translate the browsepath and to for companion specifications later: basys40.de

• Which facets are required minimum?
  • Possible:
    • OC: NONE, OCCUPIED, PRIO
    • EM: NONE, AUTO, SEMIAUTO, MANUAL, SIMULATE
    • ES: Minimum / full PackML
    • OM: BSTATE
  • Suggested:
    • OC: OCCUPIED, PRIO
    • EM: AUTO, MANUAL
    • ES: Minimum PackML (Start, Stop, Reset, Abort and corresponding states)
    • OM: BSTATE

Virtual Automation Bus (VAB) implementation

Eclipse BaSyx connects BaSyx control components as elements to the Virtual Automation Bus (VAB), the End-to-End communication infrastructure of Eclipse BaSyx. Every BaSyx control component needs to implement the minimum VAB interface that is described in this section. The following table illustrates the minimum set of VAB attributes and operations for control components that are connected to the virtual automation bus. The predefined property group STATUS lists all propertys describing the current status of the control component, respectively its state machine states. The predefined OPERATIONS group implement the minimum API for every control component that enables the control of its states via the previously described state machines.

Attribute path (output)	Corresponding state machine	Description
STATUS/OCCST	Occupation	Current occupation state
STATUS/OCCUPIER	Occupation	ID of current occupier
STATUS/EXMODE	Execution mode	Active execution mode
STATUS/EXST	Execution state	Active execution state
STATUS/OPMODE	Operation mode	Active operation mode
STATUS/WORKST	Work state	Current work state
STATUS/ER	Error state	Current error state
Operations	Corresponding state machine	Description
OPERATIONS/FREE	Occupation	Free component occupation if sender is occupier
OPERATIONS/OCCUPY	Occupation	Occupy component
OPERATIONS/PRIO	Occupation	Occupy component with priority
OPERATIONS/AUTO	Execution mode	Change to execution mode AUTO
OPERATIONS/MANUAL	Execution mode	Change to execution mode MANUAL
OPERATIONS/START	Execution mode	Start selected operation mode
OPERATIONS/RESET	Execution mode	Reset completed or stopped control component
OPERATIONS/ABORT	Execution mode	Abort operation
OPERATIONS/STOP	Execution mode	Stop operation
OPERATIONS/CLEAR	Execution mode	Clear aborted execution state
OPERATIONS/BSTATE	Operation mode	Reset the operation mode to basic state

Technology mappings

The BaSys 4.0 project has defined technology mappings for the device interface that are implemented by the Virtual Automation bus. BaSyx users may define additional technology mappings for other types of networks and bus systems, and include them by creating BaSyx Virtual Automation Bus (VAB) Gateways.

OPC-UA

This section defines a mapping of the BaSys 4.0 control component interface to OPC-UA. Our OPC-UA mapping maps VAB operations to OPC-UA methods and VAB attributes to OPC-UA variables, resprectively properties. Eclipse BaSys will provide a generic BaSyx OPC-UA gateway component to connect control components with the OPC-UA interface from this section to the virtual automation bus and therefore enables accessing of the control component status and services. Developers therefore only need to implement this OPC-UA object structure to ensure a BaSyx conforming component. The control components browsename itself is not relevant as it is identified by its node id corresponding to the VAB elementId. The namespace index of all browse names should be the basys namespace basys40.de.

Relative OPC-UA browse path	Node class	Data type
STATUS/OCCST	Variable	String
STATUS/OCCUPIER	Variable	String
STATUS/EXMODE	Variable	String
STATUS/EXST	Variable	String
STATUS/OPMODE	Variable	String
STATUS/WORKST	Variable	String
STATUS/ER	Variable	String
STATUS/FREE	Method
STATUS/OCCUPY	Method
STATUS/PRIO	Method
STATUS/AUTO	Method
STATUS/MANUAL	Method
STATUS/START	Method
STATUS/RESET	Method
STATUS/ABORT	Method
STATUS/STOP	Method
STATUS/CLEAR	Method
STATUS/BSTATE	Method

Additional gateways may implement additional mapping schemes, and may include control components and devices with non-conforming interfaces by implementing component and device specific mappings that provide a conforming façade to the VAB.