SV: SV: SV: SV: SV: FW: [plcs-dex] Unique constraints -> identification and versioning

[<mats.nilsson@fmv.se>]

David: 
As far as I know, SC4 hasn't presented any requirements on how the OASIS PLCS TC defines its Reference Data. I do not wish (at least I have no plans of putting any major effort into it) to change how the entity types are defined in the AP, but I will put some effort into creating a format for PLCS Reference Data which fills as many purposes in a good way as possible.

Sean:
A merry Christmas to you too!

Regards,
  Mats

P.S.
 I wish all who's been reading my posts (not only Sean), a merry Christmas and a happy New Year!


-----Ursprungligt meddelande-----
Från: David Price [mailto:david.price@eurostep.com] 
Skickat: den 20 december 2006 13:01
Till: plcs-dex@lists.oasis-open.org
Ämne: Re: SV: SV: SV: SV: FW: [plcs-dex] Unique constraints -> identification and versioning

On Wednesday 20 December 2006 11:38, mats.nilsson@fmv.se wrote:
>
> Another comment (which is more of a new topic) on you example,
>
> >
> > A SerialNumber is a unique number that is one of a series assigned for
> > identification which varies from its successor or predecessor by a fixed
> > discrete integer value.
>
> I think we should try to avoid using the term(s) of the class/concept we
> try to define, within the defining text.

I used this format because it's what SC4 requires for defining entity types in 
AP239 so I thought it would be familiar. If you want to propose a different 
convention to the PLCS TC and get them to approve it, have fun ... that's too 
much effort for too little gain for me:-)

Note that the format you used is how dictionaries define terms. The convention 
of a dictionary is typically to specify a phrase that could be substituted in 
a sentence instead of the defined term. However, in an RD you are not 
defining a natural language, you're specifying the semantics of a class (i.e. 
you're specifying its membership). That seems closer to me to the SC4 intent 
than to writing a dictionary.

Cheers,
David