Yes. In 30 years of programming I only met two people who knew what it was.
I don't think it is taught in school any more. I would hate to see it
disappear which is why I brought up the subject. It has come to my rescue in
dozens of situations.
Programming and debugging a finite state machine application is almost
trivial. The hard part is determining the states. But that part is done with
paper and pencil before one begins coding.
The books on the subject have relatively simple examples so the student
doesn't really see the value of it.
Here is an easily understood sample from my experience:
My project was for a machining company that used CNC to mill metal parts.
Their programmers would prepare the CNC instructions on CAD computers but
not being totally skilled in milling techniques there would be mistakes. So
they wanted a way to read back and repair the command tapes quickly without
having to go back to the CAD programs and try to figure out what went wrong.
A programmer was working on this project for a year in Basic using lots of
If-Then-Else logic and never got it to work. Using FSM I solved the problem
in three days. Unfortunately the IT manager had no clue what I was talking
about. On top of that the owner of the company signed papers to sell the
company on the day I was to give a demonstration and everything was
canceled.
Think about it. CNC commands are free-form and streaming. That is, there is
a one-byte command followed by one to four digits representing a number such
as size of bit, distance to move, coordinates, etc.
Try to create the If-Then-Else scenario. If the byte is a command, then look
at next byte. Is it a command? Is it is number? And so on for fifteen or
twenty commands. It is a rat's next of logic.
Decoding/parsing commands such as needed in compilers is a natural for FSM.
Real-life examples are much more difficult to find the states but it can be
done. I once applied for a job at a firm that does product placement. They
contracted with clients to determine how to match products with customers.
They would break out patterns of customers: those that liked hot, or salty
or special flavors or speed, etc. and tweak the products to match these
various categories.
The engineer that I interviewed was describing his programming efforts and I
said it looked like a situation for the FSM. He immediately jumped out of
his seat and said that's exactly what he was doing and ran to fetch his
design notes to show me.
Nick Geti
----- Original Message -----
From: "Jean MAURICE" <[email protected]>
To: <[email protected]>
Sent: Thursday, December 19, 2013 12:21 AM
Subject: Re: Finite State Machine
I think I do ! In fact I am not sure with the translation.
When you have a lot of 'states' and a lot of conditions, you built an
array. With one line per state and one column per condition. In each cell
of this array, you get the index of the next state you must go and the
name of the procedure you must execute.
Is that what you are dealing with ?
The Foxil
[excessive quoting removed by server]
_______________________________________________
Post Messages to: [email protected]
Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox
OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech
Searchable Archive: http://leafe.com/archives/search/profox
This message:
http://leafe.com/archives/byMID/profox/B80FE4164F434891A8311CAFB7C30EDF@dual
** All postings, unless explicitly stated otherwise, are the opinions of the
author, and do not constitute legal or medical advice. This statement is added
to the messages for those lawyers who are too stupid to see the obvious.
