add constraints for port connectors

[minhnh]

• No connection across containers' boundaries allowed, i.e. ports of a block can only be connected to ports of its "siblings" (blocks which have the same container) or ports of its container (scoping)
• A connection between 2 ports should not be repeated (checking rule)
• A DataConnector or TriggerConnector should not connect a port to itself (checking rule)
• A connector cannot connect ports of the same block (checking rule)
• port direction constraint for ports of parent block vs sibling blocks (checking rule)
• ports of the same block should have unique names (checking rule)
• there should be no unconnected port (checking rule)
• constraints on whether a data connection should be allowed:

data connection to	FunctionBlock	DataBlock	SchedulerBlock
"sibling" FunctionBlock	n	y	n (?)
"sibling" DataBlock	y	?	y (?)
"sibling" SchedulerBlock	n (?)	y (?)	n (?)
containing FunctionBlockContainer	y	y	y (?)
containing DataBlockContainer	-	y	-

• constraints on whether a trigger connection should be allowed

trigger connection to	FunctionBlock	SchedulerBlock
"sibling" FunctionBlock	?	y (?)
"sibling" SchedulerBlock	y (?)	y (?)
containing FunctionBlockContainer	y	y

[minhnh]

• DataConnector or TriggerConnector shouldn't connect ports which both have In or Out direction

[svenschneider]

All those constraints apply for the trigger connections, too.

[svenschneider]

We should enforce a unique name/identifier policy on the ports in the same block.

[scymtym]

Can we take some of the necessary constraints from the NPC 4 paper like Herman suggested?

[svenschneider]

Of course! It would be nice if we were able to "reuse" the constraints in other BPC-compliant metamodels (e.g. by M2M transformations).

[minhnh]

@scymtym could you link to the NPC 4 paper here as well for reference?

[scymtym]

@scymtym could you link to the NPC 4 paper here as well for reference?

The paper can be found here: https://core.ac.uk/display/45288978

[minhnh]

I will reopen this issue with for constraints on which data connection to be allowed.