Just to conclude this thread, I wanted to share that I found an example 
program in the 7-17-2016 Unix(7) manual page that uses the newer 
SOCK_SEQPACKET socket types. My older 2012 manual page does not. I don't 
mind feeling old, but I like to think I still know something, so I'll 
sleep well tonight and brag to my wife tomorrow.

The example even calls the exchanged messages "commands" so the Linux 
experts are thinking like us, or maybe more like you.

And remember, I use freepascal because I can't program in C. Younger 
programmers should be younger.

Speaking anatomically, how the server "brain" controls and gets feedback 
from several client "limbs" in an industrial automaton is academic. For 
me it's nice to know linux is available.

And that energy link provided earlier is a hot topic. Cybersecurity, 
various climate and technology and efficiency issues, etc. invite 
existing Linux capabilities. Lots of blanks to fill in by lots of young 
people inventing their future. Ooops, sorry to lecture. Thanks.

Iznogoud wrote:
> Got it Rick. Yes, we discussed this before; for high-fidelity acquisition
> measurements you will need precise time. You do not want a soft timer for
> that, but something that queries the hard clock.
>
> If you can afford having a process devoted to full-time data acquisition
> (and you should if you need it), have it making continuous queries to the
> clock and decide to trigger the acquisition event. With some offline tests
> and experimentation you can associate a time-scale with the response from
> the data-acquisition interface such that data is perfectly matched to an
> objective time. Peg the process to a core and keep it there.
>
> There has got to be a lot of work done on this. People do super high
> frequency measurements with proper hardware, and I am sure somebody out
> there has pushed the limit of it under some Linux setup.
>
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