SDL-News: Reply to Pragmadev, re: standards

Subject: SDL-News: Reply to Pragmadev, re: standards
From: William H. Skelton (
Date: Mon Nov 24 2003 - 14:15:03 GMT

Become an SDL Forum Society member <>
The originator of this message is responsible for its content.
-----From "William H. Skelton" <> to sdlnews -----

Dear Emmanuel,

Thank you for your comments and my apologies if there have been problems
with your email. An email was sent to you by one of my colleagues,
Stephen, on the 19th November; please double-check and if you didn't
receive it, we can forward to you again.

You are mistaken about one thing; the task force was not "set up to define
a sub-set of SDL so that it is supported by all tools" and I'm sure the
committee would not be prepared to commit to such a limiting mandate, an
almost impossible task!

No, the purpose is to define the smallest, useful subset with extensions
for test capabilities. Although we discussed this in some detail, I
understand it is easy to confuse the two targets.

Of course it is highly likely that as a result the subset will be supported
by available tools, but this is not part of the task force mandate and the
subset is open for tool manufacturers to support, iff they support it
fully, including extensions and without modification.

The committee has two commercial organisations, one of them (SOLINET) is a
tool supplier. There are two universities and one board member of the SDL
Forum. As I explained to you at the time, a committee has to be focused
and therefore limited in size, but you are welcome to participate as task
force member.

Just for reference, which SDL standard does your company, Pragmadev, comply
with? I remember your product has some interesting SDL extensions for
real-time execution; do you have any plans to introduce these to the SDL

Generally speaking, I would also be interested to know, following the
SDL'03 panel discussion on this subject, if any tool supplier now supports
the SDL-2000 standard?

When the task force committee was assembled, SOLINET was included to make
sure there is 'at least one supplier committed to supporting the
result'. Something that seems very sensible to me, looking back on the
problems encountered with previous activities.

Looking forward to seeing your emails on the task force mailing list!...


At 12:53 24.11.2003 +0100, Emmanuel Gaudin wrote:
>I must say I have the same feeling than Keith here.
>I told you in Stuttgart I wanted to actively participate in the task force
>but then you told me the committee was settled and could not accept any one
>else... You suggested I could join the task force and participate to the
>discussions. So I sent a mail to the 27th of August
>in order to join the task force but I never received any reply. I actually
>thought nothing was going on !
>I am very surprised because this task force has been started to define a
>sub-set of SDL so that it is supported by all tools; as far as I know, you
>are the only tool vendor working on this. Am I right ?
>Could you please clarify your position and would it be possible to have the
>point of view or commitment from the other tool vendors ?
>Emmanuel Gaudin
>tel: +33 1 42 74 15 38
>fax: +33 1 42 74 15 58
>-----Original Message-----
>[]On Behalf Of William H. Skelton
>Sent: Friday, November 21, 2003 2:28 PM
>Subject: [SDLTF-Members] SDL Task Force Reply to Keith Moss
>Dear Keith,
>Thank you for raising this issue, which I would like to comment on.
>The SDL Task Force has been active, but as I mentioned before, the main
>contribution has been from the committee (Alkis Yiannakoulias, Qing Li,
>Vangeli Kollias, Andreas Prinz & myself).
>There have been meetings with more active members, such as the Daniel Amyot
>& Alan Williams, who as you probably know are also hosting the SAM workshop
>next year, Alcatel & Motorola, but the results have been edited into the
>draft specification without details of the discussions themselves.
>I am sorry if you have the impression that this has been 'behind closed
>There is not an 'inner committee', but a committee of people, who are
>funding this activity themselves without external support. The publication
>of results is voluntary and intended to help the further development of SDL.
>The draft specification, which is published at, is
>actually not even a draft, but a working form of the planned draft.
>Comments are invited for the further evolution.
>If you feel there has not been much visible communication on this subject, I
>warmly welcome you to address your comments to the task force. I have
>inserted my personal opinion at several points below, but suggest the
>discussion should continue on the task force mail exploder. :-)
>Just checking now with my colleagues, it seems you use two email addresses
>(AOL & IEEE), but only the IEEE address is registered with the mail server.
>This may lead to your emails not being accepted.
>Date: Tue, 18 Nov 2003 04:55:14 EST
>Subject: [sdl-forum] SDL-news: task force
>Dear All
>I was prompted to write this email after I had read the email exchange
>between Rick and William. Until then even though I have signed up to be a
>member of
>the task force I was not aware of any activity even though I had twice
>corresponded with William on just that subject.
>As far as I'm concerned the inner committee appears to be conducting affairs
>behind closed doors. However I have now read the latest documentation the
>draft specification and I have a few observations.
>I feel that the specification needs to be presented in graphical format as
>this is much easier to understand especially for new users and for
>for users who are programming experts. A diagram helps immensely to explain
>idea and can be just as rigorous in definition. Many of the paragraphs in
>document could be reduced if only the relevant diagram were present.
>I'm all for simplification, but to be honest, I think the text is necessary
>and have tried hard for it to be easy to understand. Certainly compared to
>the ITU-T specifications, I think this criticism is a bit harsh. :-)
>If you would like to make a suggestion how to represent these concepts
>graphically, I would be glad to take it further.
>I feel that SDl should be universal and separate domains of interest are
>likely to lead to fragmentation of the SDL forum.
>There is no fragmentation, participation is open to anyone from the SDL
>There is a section "State-Event matrix" which mentions constraints without
>ever explaining what a constraint might be. If the subset is ever to be
>considered a simplification then there needs to be less abstract ideas
>You're right, constraints needs explaining. They are a generalisation taken
>from testing concepts, where one can see even specifying only the expected
>signal name can be considered to be a constraint on the received signal. In
>testing concepts one sees the constraints as mainly to do with the expected
>values for parameters, but it can be generalised to be anything to do with
>the signal, also the gate it arrives on.
>As I understand one of the objectives is to make SDL more universally used
>and this can only be achieved if the initial contact is easy to assimilate.
>I also feel that the "Save" construct is much easier to understand than many
>of ideas to be incorporated. I don't buy the idea that it complicates
>If a queue has to be designed to cover the loss of the "save" construct, the
>queue will have to managed.
>The point is explained actually in some detail; the use of a queue is an
>application related issue, not a system issue. If you want a queue, declare
>it and use it with add/remove functions where and when you need it.
>Utilising an implicit system feature of buffering on a gate, because 'the
>mechanism is probably there anyway', hides the application related
>functionality and makes a system less readable.
>Some people have said it makes a system more readable, even though the
>principle is actually deeper than that. To make a decision on this, we
>concluded it is not needed for implementing the 'simplest, useful' SDL
>systems, and it was removed.
>Regards Keith Moss (Task force member?)
>ps I have sent this to the SDL news as I appear to have no priviledges to
>send to the task force even though I'm supposed to be a member
>William H. Skelton, Engineering Dept.
>SOLINET GmbH Solutions for Innovative Networks
>Mittlerer Pfad 26, 70499 Stuttgart, Germany
>Tel +49 711 1398 1377, Fax +49 711 866 1240
>Mobile +49 171 247 6688

William H. Skelton, Engineering Dept.
SOLINET GmbH Solutions for Innovative Networks
Mittlerer Pfad 26, 70499 Stuttgart, Germany
Tel +49 711 1398 1377, Fax +49 711 866 1240
Mobile +49 171 247 6688,

--End text from "William H. Skelton" <> to sdlnews ---
For extra SDL Forum Society benefits join at <>

This archive was generated by hypermail 2a23 : Thu May 09 2013 - 16:05:50 GMT