(10059) 'Interfaces on Flow Ports': Recommend use nested ports

Issue example:

'For example, I could use communicate in morse code over a hydraulic line.
This would be modeled normally as a standard (service) port, except for the medium.'

Handled here using nested ports in MD SysML.

One could optionally conjugate one of the standard ports to emphasise asymmetric connections. 

(10342) 'Section: 9.3.2.8 ItemFlow'

There are genuine issues concerning the inability to type an ItemFlow.itemProperty[0..1] by a Signal (see metamodel analysis bottom).

The diagram below shows three different usages of the ItemFlow label on a Connector:

• InformationFlow showing Signal as conveyed:Classifier, matching the flowports
• ItemFlow.itemProperty typed by a ValueType (can't match Signal)
• ItemFlow.itemProperty typed by a Signal (breaks SysML1.0 constraints)

(10371) RECOMMEND: use both default value "callout" into a note and 'initial values' compartment in an IBD

In MD SysML you can callout a default value of FlowPort into a Note.

This can be combined with the initial values (SysML1.0 defaultValue) compartment in a higher context
to display both a class-level and property-specific initial values for a flowport typed by a ValueType.

(11599) "Fix for Fig 9.4 p70"

I suggest use 'put' as shown:

Visit also:

• Figure B.20 - Interfaces Typing StandardPorts Internal to the Power Subsystem (ICE Interface Definitions)
• Figure B.19 - Internal Structure of the Power Subsystem (Alternative 1 - Combined Motor Generator)

(11628) Consider nested ports

(12222) 9.3.2.3 FlowPort, 9.3.2.7 Standard Port: formally permit useful idiom of flowport nested within standard port

Experience modelling a wide range of heterogeneous systems has proven that the representation of logical channels as information flows across connections between flowports nested within standard ports is a very useful idiom. It would help if this possibility is explicitly stated in both 9.3.2.3 FlowPort, 9.3.2.7 Standard Port, and illustrated in specification figures.

Example: a software application acquires encoded signals representing physical positon and rotation via a high-level software API to a low-level A./D card in a computer. The software application is connected to an A/D module subject to a contract represented by an Interface provided by a standard port (subject ot a protocol). The flow of information corresponding to logical acquired channels can be well represented as flowports nested within the standard port of the A/D module.This example is illustrated in detail at:

(12222) flowports nested within standard ports

Visit also:

• HOWTO use nested flowports within standard ports to model logical channels