Value Type, Quantity Kind and Units

[s_eauser]

I am confused about value types. I understand that quantity kind could mean a physical quantity like temperature and the unit is the SI unit of measure degree centigrade. What exactly is value type here? Is it the description of the value I am trying to measure?

For example:
Value Type: Micro-controller Temperature
Quantity Kind: Temperature
Unit: Degree Celsius

[philchudley]

A ValueType is used, typically, as a typing mechanism for Value Properties (in a Block), Flow Property (in an Interface Block), or for a Port (most likely a Proxy Port)

So yes, it can represent what you are trying to measure. For example, a Block that is monitoring temperature could have a Value Property named currentTemperature, typed to a ValueType named AmbientTemperature with Quantity Kind = temperature and Units = degree Celsius. This Block could also have a Proxy Port named Temperature In typed to ValueType named AmbientTemperature

Hope this helps

Phil

[kwasposer]

Hello, is there actually a SI Unit library available?

Anyway I tried to model Units , quantiykind and value types.
Why do Units not have the stereotype "Unit" but the "Type" = Object in EA? This is different to the description of SYSML Specification

[qwerty]

How about starting one and placing that on github to have it expanded by the community? I don't think there is one outside already.

q.

[kwasposer]

Sorry, I dont get your hint. Do you wnat me to create always a new post, even if there is the same topic in the past. Anyway. Maybe you can help me again qwerty.

How can I make  the type of Unit visible, as seen in the screenshot of the ea model example hsuv?

[kwasposer]

Ok I copied the Package <<ModelLibrary>> Unit and Qunatity Kind Library
from the EA Example

and than I choose the Property Tab and changed the field Object/Classifier to <<block>>Unit

Hope it helps someone.

I checked to model example HSUV from EA.

They dont use quantity kinds.

But why do they add following association?

[kwasposer]

Why do I have to set the Classifier? What is the purpose and why does EA is not doing it on itself?

[Geert Bellekens]

If you drag the block Unit on a diagram as an instance you won't have to set the classifier manually.

Geert

[kwasposer]

aah, ok,

And is this really necessary to model like this? Do you still need to model quantityKind, too?
Is it enough to use Unit and at the Value to the Variable in the Propertie/Run State Tab?

[kwasposer]

If you drag the block Unit on a diagram as an instance you won't have to set the classifier manually.

Geert

Hello again Geert,

i have noticed, that using the instance instead of changing the Classifier, "quantityKind" value is missing in Run States.

How did they manage to have quantityKind in the Unit Instance?


https://www.sparxsystems.com/forums/smf/index.php/topic,40033.0.html#msg246055

I just try to learn from these examples, but is there a book, that describes how to model SysML with Enterprise Architect? It is a bit frustrating, that I feel I have to use more effort for Enterprise Architect than for SysML modeling. Sometimes I wished, that my boss had trusted me with Windchil Modeler or NoMagic 

[kwasposer]

Which approach is correct?

[Eve]

Hello, is there actually a SI Unit library available?

In the model wizard you'll find a couple of libraries that define the classes for Unit and QuantityKind.

If you look at https://www.omg.org/spec/SysML/1.5/About-SysML/, you'll see the QUDV and ISO-80000 packages which can be imported into EA for a very large collection of predefined types.

[EAButNotForGames]

I randomly stumbled on his thread and wanted to try the ISO 80000 Library.
But I get an error message, when selecting it in the Model Builder.

[Eve]

I randomly stumbled on his thread and wanted to try the ISO 80000 Library.
But I get an error message, when selecting it in the Model Builder.

Pro tip. It helps you to get useful replies when you provide the error message instead of just saying you got one.

[EAButNotForGames]

The Error Message is:

Unable to connect to service
Http Status Code: 403 Forbidden

So far, everyone in my company gets this error.