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Newsgroups: comp.lang.ada
Date: Mon, 25 Feb 2019 13:18:28 -0800 (PST)
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Subject: Re: Ada in command / control systems
From: Jesper Quorning <jquorning@hotmail.com>
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Xref: reader01.eternal-september.org comp.lang.ada:55663
Date: 2019-02-25T13:18:28-08:00
List-Id: <comp.lang.ada>

On Monday, February 25, 2019 at 9:24:33 AM UTC+1, Dmitry A. Kazakov wrote:

> Because the PLC marked is dominated by vendors pushing their vendor-lock=
=20
> solutions, e.g. Siemens.

Siemens is the Apple of the industrial world. They have to lock the hardwar=
e to keep up the quality of service.

> Another reason is the customers lacking elementary programming and=20
> software design skills. They are usually technicians and electrical or=20
> mechanical engineers.

I would say that software engineering is not about knowing everything about=
 programming. it is more about not doing things which is outside your compe=
tences until you are competent enough to use the feature.

Concurrency has been done with single CPU since forever with finite state m=
achines (FSM) and cyclic executing. The PLC is not at primitive beast. It i=
s a platform with logs, priority scheduling, interrupt handling functionali=
ty on nearly everything from program errors to hardware errors, communicati=
on errors and you can inspect the program states on the fly (online debuggi=
ng). Safety is very important as the lives and economic interests of humans=
 are at stake.


        Jesper.