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=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.182.26.19 with SMTP id h19mr14181129obg.44.1460735266838; Fri, 15 Apr 2016 08:47:46 -0700 (PDT) X-Received: by 10.182.85.72 with SMTP id f8mr240780obz.6.1460735266808; Fri, 15 Apr 2016 08:47:46 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!news.glorb.com!gy3no4440159igb.0!news-out.google.com!j7ni405igm.0!nntp.google.com!gy3no4440138igb.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Fri, 15 Apr 2016 08:47:46 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=193.251.73.50; posting-account=O3LyFwoAAACc1uh60ZcOUmAGdDmGsEcV NNTP-Posting-Host: 193.251.73.50 References: <6d3b7ac5-8fc6-406c-8aac-947d25a78249@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: Simple Components 4.12 with MQTT implementation released From: slos Injection-Date: Fri, 15 Apr 2016 15:47:46 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Xref: news.eternal-september.org comp.lang.ada:30129 Date: 2016-04-15T08:47:46-07:00 List-Id: Le vendredi 15 avril 2016 17:05:56 UTC+2, Dmitry A. Kazakov a =E9crit=A0: > On 2016-04-15 12:06, slos wrote: >=20 > > We share some of the vision. > > "Ada for Automation" is a framework with which one can build his own > > control application using Ada. I would not call it a middleware. >=20 > Why not? >=20 > > And MQTT or OPC UA would just connect it to some SCADA or cloud based > > application like one using IBM BlueMix. >=20 > Neither is good for SCADA, especially regarding safety requirements and= =20 > performance. >=20 > >> Note that without OPC UA everything could work far better and require > >> far less resources. E.g. having all process data the OPC cannot access > >> because it is too slow to pace with the middleware capable to deliver > >> data at less than 1ms rate and does not properly support > >> push-subscriptions, does not support distributed time stamping, physic= al > >> units, error states etc. > >> > > I agree that OPC UA does not fit where EtherCAT, Sercos III or PROFINET= IRT would. > > OPC was created for office and SCADA / GUI applications access to > > PLC data, not for IO processing. >=20 > Why SCADA or DB server should ever use some other middleware protocols?= =20 > The point is that one middleware can stretch from the ERP levels down to= =20 > the field. Well, in this case this is no more a middleware. It's an everyware... > But when the middleware is OPC or MQTT you cannot not put it=20 > into a device and expect that working. Yes you can : http://www.hilscher.com/fileadmin/cms_upload/en-US/Resources/pdf/netIC-IOT_= Datasheet_10-2015_EN.pdf > This is the reason we must live=20 > with EtherCAT, ProfiNET down there, which are nightmare to any system=20 > integrator. That is not the case. Those standard protocols are designed with lots of go= als, among them performance and interoperability. They allow multiple vendors to propose products fitting well together and i= t works pretty well since years. > That defeats the very idea of a middleware. I don't see why. The middle of what ? Architecture is made with layers and middleware can sit between any two of = them. > The real advantage of Ada is that it is scalable from heavy duty to hard= =20 > real-time embedded. Yes, hence my choice for "Ada for Automation". > The ugly protocols like XML, HTTP, OPC etc only=20 > hinder developing of safe and efficient systems. Yes but they allow interoperability, and the web and talking to each other = whatever browser or platform we use. I think one of the problems of Ada community is a kind of sectarianism or e= litism. I agree that Ada has great qualities and could be used with huge benefits i= n most applications but there is an ocean of already available stuff that i= s not written in Ada and work anyway. That's what I am trying to do with "Ada for Automation" : gather software c= omponents, integrate them in something consistent for a control engineer an= d create sample applications to start from. If I find components written in Ada, that's great. If they are in C, that's= fine too for me. Anyway my day job is C programming and I've been programming PLCs for decad= es too. Ada is my night language... which I am still learning. >=20 > --=20 > Regards, > Dmitry A. Kazakov > http://www.dmitry-kazakov.de BR, St=E9phane