BaSyx / Documentation / API / ControlComponentProfiles

This information is work in progress as part of the BaSys 4.2 project. This section is preliminary and subject to change during the project.

Profiles

An example control component in OPC UA realizing different facets.

A profile is a composition of facets from different facet categories. For example a control component profile can be defined by the following facets.

• SI = 4 (OPERATIONS)
• OC = 6 (OCCUPIED,PRIO)
• EM = 2 (MANUAL)
• ES = 4 (PACKML)
• OM = 2 (MULTI)

The address space of a control component in OPC UA conforming to this profile is shown in the figure.

Facets ordered in different facet categories may describe a huge variety of control component realizations. Consequently, profiles are needed to reduce the amount of facet combinations to a usefull subset. Examples of control component dummies in OPC UA can be found in the [ccProfilesUA project].

Profile Definition

Every profile will refer to at least one facet from every facet category and will therefore be considered as full featured profile. Hence, applications can be developed and implemented against single facet values or whole profiles. The following profiles are currently defined and may be extended in the future:

• MINIMAL 

  Minimal requirements for the component and service interface. May be used for the integration of sensors.

• BASYS 

  Default profile for control components conform to the BaSys 4.2 project. Used in BaSys demonstrators.

• FULL 

  Maximum features of the control component with all interfaces available.

• PACKML 

  Control components that are fully compatible to PackML.

• MTP 

  Control components that are described and conform to NAMUR Module-Type-Package (MTP).

The following table defines the described profiles by referencing according facet values. As different standards like PackML allow for variations themselves (e.g. availability of SEMIAUTO execution mode), only minimal requirements are set.

Profile	Service Interface (SI)	Occupation (OC)	Execution Modes (EM)	Execution States (ES)	Operation Modes (OM)
MINIMAL	1	1	1	1	1
BASYS	4	6	6	2	2
FULL	62	14	30	3	3
PACKML	32	1	6	3	1
MTP	16	1	6	5	3

BASYS Default Profile

The default profile for BaSys control components has an OPERATIONS service interface, conform to VAB Implementation. It has a simple occupation state machine with one priorytized state (OCCUPIED, PRIO) and no local overwrite. Moreover, at least the MANUAL and AUTO execution mode must be available. As execution state machine a subset of PackML and ISA88 exuction states are selected. Multiple operation modes may be available, but only one operation mode is active at a time and needs to be selected beforehand.

Profile Interface Specification

In order to describe the variant and its features, respectively the profile, of a control component an interface specification is given here. It may be used in type or instance descriptions, e.g. in AAS submodels, or even in the control component itself. A self description of control components is an important feature to enable plug and produce scenarios.

Parent	Name	Type	Rule	Property Datatype	Property Values
	PROFILE	Property Group	Optional
PROFILE	SI	Property	Optional	String	SI Facets
PROFILE	OC	Property	Optional	String	OC Facets
PROFILE	EM	Property	Optional	String	EM Facets
PROFILE	ES	Property	Optional	String	ES Facets
PROFILE	OM	Property	Optional	String	OM Facets

Profile Compliance Testing

Compliance tests need to be defined in order to verify that a control component conforms to a profile or specific facets. These tests can be static, checking the interface according to the interface specifications in the SI Facets. Moreover, behavioural tests can be defined based on the standardized state machines. These test may be even be used to explore the profile of an unknown control component, which could be used in a plug and produce procedure for example.

An implementation and description for test cases and example dummies in OPC UA utilizing the Google-Test framework can be found [ccProfilesUA project].

Facet Categories

BaSys control components may be described by the following facet categorys:

SI - Service Interface Facet Category

Describes how the offered services are structured and how states are represented.

This facet category is special, because it is orthogonal to the other facet categories. Hence, a control component interface looks a bit different, if different facets from the other facet categories are realised.

OC - Occupation Facet Category

Describes whether a occuption is necessary.

Variants may describe whether a occupation with priority or local is possible.

EM - Execution Modes Facet Category

Describes whether different execution modes are possible.

Variants may describe which modes are possible and how they are called.

ES - Execution States Facet Category

References the used execution states and their transitions.

May describe variants or subsets of a full execution state state machines.

OM - Operation Modes Facet Category

Describes whether multiple operation modes are available and need to be selcted.

Variants may describe whether there are specific operation modes, like fallback or startup and shutdown modes.

Facet Category Values

All facets have a name and are identfied with an positiv integer or zero. In order to combine facet category values and to use them as statements some common values are equal for all profiles, which is presented in the following table. If a facet category value is higher than one, ANY facet is defined for a facet category, which is opositional to the NONE value.

Facet categories may either describe a group of features that are combinable or a variant point that lists alternative realizations. If different facets in one facet group may be combined they are defined by bitmasks. Hence their values are multiples of two and combinations may be represented by bit order operations and integer values. Otherwise enumerations with an increment of one are used for alternative facet categories.

Bit	Value	Name	Description
1	0	UNKNOWN	No statement about profile or not determined
1	1	NONE	Facet category is not realised, used, compliant or implemented
2..n	>1	ANY	One ore more facet category values, but not specified which ones
2	2	...	First specific facet of the facet category.
n	2^n	...	Nth specific facet of the facet category.

Facets

The following table shows an overview of all facet values. The left (blue) part are combineable values realized as bitmasks, the right (green) part are alternative single values.

Bit / Value	Service Interface (SI)	Occupation (OC)	Execution Modes (EM)	Value	Execution States (ES)	Operation Modes (OM)
0 / 0	UNKNOW			0	UNKNOWN
1 / 1	NONE			1	NONE
2 / 2	CMD	OCCUPIED	AUTO	2	BASYS	MULTI
3 / 4	OPERATIONS	PRIO	MANUAL	3	PACKML	PARALLEL
4 / 8	SERVICES	LOCAL	SEMIAUTO	4	ISA88	CONTI
5 / 16	MTP		SIMULATE	5	MTP
6 / 32	PACKML			6	OPCUA
7 / 64				7	NE160

SI Facets

The control component service interface E1 may be realised in various ways. Basys classifies different realisations via facets from the SI facet category. The service interface category (SI) describes how a control component can be affected by the means of orchestration and how the resulting state changes may be observed. Therefore each facet defines how the activation interaction likewise the writing of variables or invocation of operations is handled. Moreover, a component has aggregated state values for its state machines, which may be represented by one or more variables at different adresses. State change events may be raised if state variable values change. Consequently, the SI facets also define how to find the addresses or endpoints of its activation and reaction represenations.

The following table presents an overview and small comparision of possible SI facets. The major facet for the service interface used in basys is OPERATIONS.

Bit	SI value	Name	Activation mechanism	Aggregated state represenation	Utiliziation recommendation
1	0 - 1	UNKNOWN, NONE	Not defined	Not defined	See category values
2	2	CMD	A string variable called CMD (command input) with a specific syntax is used to activate service operations	A flat list of variables of all aggregated component states under a containing element (folder)	Process control applications with IEC 61131
3	4	OPERATIONS	A flat list of operations of all offered services under a containing element (folder)	A flat list of variables of all aggregated component states under a containing element (folder)	Advanced components or as additional interface
4	8	SERVICES	Operations are grouped under service elements	State variables are grouped under service elements	Advanced and modular components
5	16	VARIABLES	Multiple (spread) variables are used to activate service operations	Multiple (spread) variables are used to represent the component states	Very generic but needs mapping description. Not standardized browseable. May be mapped to NAMUR MTP

Note on NAMUR Module Type Package (MTP): in the future, basys will map the description for the orchestration of modules that are described via a NAMUR MTP to facets or even to a profile. Therefore an existing facets like VARIABLES may be used or a new facet may be necessary.

SI Facet CMD

An example control component in OPC UA realizing the CMD service interface.

The SI facet CMD determins a control component with a command interface, based on . The command interface consists of at least one string variable called the command input or CMD, that uses the following syntax:

<Sender>;<Order>;[<Parameter1=Value1>,<Parameter2=Value2>,<...>]

Interface specification for facet CMD (All specifications: File:BaSyx-ControlComponentProfiles-Interface Specification-xls.zip):

Parent	Name	Type	Rule	Facets	Property Datatype	Property Values	Property Writeable
	CMD	Property	Mandatory	SI==2	String	[sender];[order];[param1=value1,...]	Writeable
	CMDLAST	Property	Optional	SI==2	String	[last accepted command]
	CMDOLIST	Property	Optional	SI==2	String[]	[list of supported orders]
	CMDOPREF	Property	Optional	SI==2	String[]	[list of required parameters for each order]
	STATUS	Property Group	Mandatory	SI==2
STATUS	ER	Property	Mandatory	SI==2	String	Error States
STATUS	ERLAST	Property	Optional	SI==2	String	Error States
STATUS	WORKST	Property	Mandatory	SI==2	String	Work States
STATUS	OCCST	Property	Mandatory	SI==2 && OC > 1	String	Occupation States
STATUS	OCCUPIER	Property	Mandatory	SI==2 && OC > 1	String	[occupier id]
STATUS	OCCLAST	Property	Optional	SI==2 && OC > 1	String	[id of last occupier]
STATUS	EXMODE	Property	Mandatory	SI==2 && EM > 1	String	Execution Modes
STATUS	EXST	Property	Mandatory	SI==2 && ES > 1	String	Execution States
STATUS	OPMODE	Property	Mandatory	SI==2 && OM > 1	String	Operation Modes

Some major advantages of this facet are:

• The CMD variable is a single endpoint for orders. So an (atomic) write operation is sufficient to for every order including parameter setting.
• The CMD input is easy to use and implement in different technologies, as only the transfer of a string is necessary.
  • The control component can process the command asynchrounus in its own cycletime.
  • No operations are needed. Some technologies or embedded devices (especially PLCs) do not provide invokation or remote procedure call functionality.
• The control component does an implicit type conversion for parameters, so no user side browsing for exact types and casting is necessary.
• Parameters may even be written separately, before sending an command, if they are realised as own variables. This is usefull for default parameters or if different sources are responsible for different parameters.
• A batch of commandos is easily human readable.

SI Facet OPERATIONS

An example control component in OPC UA realizing the OPERATIONS service interface.

The SI facet OPERATIONS determines a control component service interface with a flat list of operations. Operation names are equal to the order names in the command input. Hence, a operation call corresponds to a command request.

Interface specification for facet OPERATIONS (All specifications: File:BaSyx-ControlComponentProfiles-Interface Specification-xls.zip):

Parent	Name	Type	Rule	Facets	Property Datatype	Property Values
	OPERATIONS	Property	Mandatory	SI==4	Map
OPERATIONS	FREE	Operation	Mandatory	SI==4 && OC&(2|4)
OPERATIONS	OCCUPY	Operation	Mandatory	SI==4 && OC&2
OPERATIONS	PRIO	Operation	Mandatory	SI==4 && OC&4
OPERATIONS	AUTO	Operation	Mandatory	SI==4 && EM > 1
OPERATIONS	MANUAL	Operation	Mandatory	SI==4 && EM&2
OPERATIONS	SEMIAUTO	Operation	Mandatory	SI==4 && EM&4
OPERATIONS	SIMULATE	Operation	Mandatory	SI==4 && EM&8
OPERATIONS	START	Operation	Mandatory	SI==4 && ES > 1
OPERATIONS	STOP	Operation	Mandatory	SI==4 && ES > 1&& ES!=7
OPERATIONS	RESET	Operation	Mandatory	SI==4 && ES > 1&& ES!=7
OPERATIONS	ABORT	Operation	Mandatory	SI==4 && ES > 1&& ES!=6
OPERATIONS	CLEAR	Operation	Mandatory	SI==4 && ES > 1&& ES!=6
OPERATIONS	HOLD	Operation	Mandatory	SI==4 && ES > 2&& ES!=6
OPERATIONS	UNHOLD	Operation	Mandatory	SI==4 && ES > 2&& ES!=6
OPERATIONS	SUSPEND	Operation	Mandatory	SI==4 && ES > 2&& ES!=7
OPERATIONS	UNSUSPEND	Operation	Mandatory	SI==4 && ES > 2&& ES!=7
OPERATIONS	CONTI	Operation	Mandatory	SI==4 && OM==4
OPERATIONS	STARTUP	Operation	Mandatory	SI==4 && OM==4
OPERATIONS	SHUTDOWN	Operation	Mandatory	SI==4 && OM==4
	STATUS	Property Group	Mandatory	SI==4
STATUS	ER	Property	Mandatory	SI==4	String	Error States
STATUS	ERLAST	Property	Optional	SI==4	String	Error States
STATUS	WORKST	Property	Mandatory	SI==4	String	Work States
STATUS	OCCST	Property	Mandatory	SI==4 && OC > 1	String	Occupation States
STATUS	OCCUPIER	Property	Mandatory	SI==4 && OC > 1	String	[occupier id]
STATUS	OCCLAST	Property	Optional	SI==4 && OC > 1	String	[id of last occupier]
STATUS	EXMODE	Property	Mandatory	SI==4 && EM > 1	String	Execution Modes
STATUS	EXST	Property	Mandatory	SI==4 && ES > 1	String	Execution States
STATUS	OPMODE	Property	Mandatory	SI==4 && OM > 1	String	Operation Modes

OC Facets

The occupation facet category describes, whether a control component can be occupied. This is important for an orchestrator, as it has to be checked, whether the component is free and it has to be occupied before operation. Further more, the occupation facets determine, whether it is possible to occupy the component with a higher priority, for example by an operator or maintenance person. An OC value of two or higher (ANY) requries the component to have an OCCUPIER variable to determine who occupies the component. Moreover, the OCCST variable is needed to differentiate occupation states.

Bit	Value	Name	Description	Possible OCCST values	Possible ORDERs
-	0	UNKNOWN	See category values	Undefined	Undefined
1	1	NONE	No occupation necessary	-	-
2	2	OCCUPIED	Normal occupation possible	FREE, OCCUPIED	FREE, OCCUPY
3	4	PRIO	Priority occupation possible	FREE, PRIO	FREE, PRIO
4	8	LOCAL	Local overwrite	FREE, LOCAL

EM Facets

The execution mode facet category describes which execution modes are available. A component is assumed to be in AUTO like mode at all time, if the EM value is NONE. An EM value of two or higher (ANY) requires a EXMODE variable to determine the current mode.

Bit	Value	Name	Description	Possible EXMODE values = Possible ORDERs
-	0	UNKNOWN	See category values	Undefined
1	1	NONE	Always in AUTO	-
2	2	AUTO	Additional AUTO mode available	AUTO
3	4	MANUAL	Additional manual mode available	MANUAL
4	8	SEMIAUTO	Additional semiautomatic mode available	SEMIAUTO
5	16	SIMULATE	Additional simulation mode available	SIMULATE

ES Facets

In general different execution state machines or subsets are used in different domains or companies. BaSys recommends the use of the PackML state machine, as it is possible to map at least state and order names of other state machines to it. At the moment only the facets 0 to 4 are supported in basys and are therefore used in the full featured profiles.

The EXST variable has to be present, if an ES value of two (ANY) or higher is given. A control component with ES value one (NONE) is assumed to be in the EXECUTE state at all time and hence it can not be halted, suspended, stopped or aborted.

Value	Name	Description	Reference
0	UNKNOWN	See category values	-
1	NONE	Always in EXECUTE state	Minimal state model
2	BASYS	Subset of PackML (Start, Stop, Reset, Abort)	Minimal PackML state machine
3	PACKML	PackML state machine	ISA TR88.00.02-2008
4	ISA88	ISA88 procedural elements state machine	ANSI/ISA-88.00.01-2010
5	MTP	MTP state machine	MTP Part 4
6	OPCUA	OPC UA program state machine	OPC UA Part 10
7	NE160	NE160 procedure state machine	NAMUR NE160

Even though the state machines differ in their number of states, their names can be mapped to each other, as shown in the following table. The MTP column also shows corresponing bit numbers.

Order	BASYS	PACKML	ISA88	MTP	OPCUA	NE160
START	START	Start	START	Start(2)	Start	START
STOP	STOP	Stop	STOP	Stop(3)	Halt
RESET	RESET	Reset	RESET	Reset(1)	Reset
ABORT	ABORT	Abort	ABORT	Abort(8)		ABORT
CLEAR	CLEAR	Clear	RESET	(Reset(1))		RESET
HOLD		Hold	HOLD	Hold(4)		LOCK
UNHOLD		Unhold	RESTART	Unhold(5)		UNLOCK
SUSPEND		Suspend	PAUSE	Pause(6)	Suspend
UNSUSPEND		Unsuspend	RESUME	Resume(7)	Resume
Not Assigned				Restart(9)		RESTART

OM Facets

The operation mode facets define whether different operation modes are selectable. A control component with an OM value of two or higher has to represent the current operation mode via OPMODE state variable. The OM value NONE yields to a control component, that has no operation modes to select and is therefore assumed to be in basic state (BSTATE) at all time.

Value	Name	Description
0	UNKNOWN	See category values
1	NONE	No operation mode selection possible.
2	MULTI	One or multiple, application specific modes, that need to be selected.
3	PARALLEL	Parallel executable operation modes with own execution states. See components with concurrent behavior.
4	CONTI	Conti process operation mode with startup and shutdown: CONTI, STARTUP, SHUTDOWN