From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=AC_FROM_MANY_DOTS,BAYES_00 autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,ebdcfc7163c60d32 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-09-24 07:56:58 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.uchicago.edu!vixen.cso.uiuc.edu!howland.erols.net!newsfeed.mindspring.net.MISMATCH!newsfeed0.news.atl.earthlink.net!murphys.news.atl.earthlink.net!news.atl.earthlink.net!stamper.news.atl.earthlink.net!harp.news.atl.earthlink.net!not-for-mail From: "Marin David Condic" Newsgroups: comp.lang.ada Subject: Re: Distributed programming in heterogenous platforms Date: Tue, 24 Sep 2002 08:05:22 -0400 Organization: MindSpring Enterprises Message-ID: References: <3d8f3d90_1@news.tm.net.my> <3D8F49D8.8000605@worldnet.att.net> NNTP-Posting-Host: d1.56.ba.76 X-Server-Date: 24 Sep 2002 12:06:24 GMT X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2314.1300 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300 Xref: archiver1.google.com comp.lang.ada:29311 Date: 2002-09-24T12:06:24+00:00 List-Id: The approach of building heterogeneous systems utilizing message passing in one form or another is *extremely* popular in military systems. Often, its just Mil-Std-1553 32 word messages for the sake of simplicity, but I've personally worked on a number of projects dealing with radio communications and rocket launching that have been based on message passing in various forms. (Anybody ever heard of the TADIL-J catalog?) It has its strengths and weaknesses. Obviously, once you define the message format with high precision, any computer capable of connecting to the network can play and it doesn't need any specific OS or programming language. The bad news is that message catalogs can get quite large and complex and the protocols for getting units talking to each other with the right timing and information sometimes gets very convoluted. (O.K. First, I'll tell you to get started, then you ask this other guy for this data. When you get it, you let me know and start your power up cycle. In the mean time, I'll be talking to that other guy over there and asking him to send you blah blah blah... :-) Message passing systems are so common in military hardware that I'm suprised that Ada didn't manage to get that quite right. It *almost* works to try to build message catalogs with tagged records, but since you can't control the representation sufficiently, you just can't use them to play in that sandbox. The only way to do it is to resort to kludges that might just as well have been written in C. MDC -- ====================================================================== Marin David Condic I work for: http://www.belcan.com/ My project is: http://www.jast.mil/ Send Replies To: m c o n d i c @ a c m . o r g "I'd trade it all for just a little more" -- Charles Montgomery Burns, [4F10] ====================================================================== Jim Rogers wrote in message news:3D8F49D8.8000605@worldnet.att.net... > > This reference is a bit indirect, but the problem is the same. > > I worked on some robotic systems for the U.S. Army. The Army was interested > in developing an architecture allowing modules from various vendors, > implemented using different languages and hardware, to work together. > They developed the Joint Architecture for Unmanned Ground Systems (JAUGS). > > This is primarily a message based architecture. The messages are defined > independent of any language, with a specified byte order. Messages can be > separated into two broad classifications; periodic messages and events. > > The architecture is defined at http://www.jaugs.org/ > > Jim Rogers >