Groups > sci.electronics.design > #453957

Re: Output boards, SPI vs I2C

From	rickman <gnuarm@gmail.com>
Newsgroups	sci.electronics.design
Subject	Re: Output boards, SPI vs I2C
Date	2017-03-28 02:16 -0400
Organization	A noiseless patient Spider
Message-ID	<obcutl$24o$1@dont-email.me> (permalink)
References	(4 earlier) <ob8ju3$ap4$1@reader1.panix.com> <ob8r5i$ua3$1@dont-email.me> <ob960e$p4u$1@reader1.panix.com> <obb8jp$ur3$1@dont-email.me> <obcr45$6ss$1@reader1.panix.com>

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On 3/28/2017 1:08 AM, David Lesher wrote:
> rickman <gnuarm@gmail.com> writes:
>
>
>> I'm no expert on PLC, but if you aren't using any of the
>> hardware I would suggest you get a microcontroller board
>> instead.  There are TONs of good products that are smaller and
>> more cost effective.  But I believe PLCs often have a special
>> language for programming, ladder logic.  I didn't think it was
>> used much even for PLCs though.
>
> We don't want ladder-logic. This box was suggested by folks
> using them & the programmer is happy so far.
>
> Its advantages are it's already built, has most of the
> functionality we need in one box, and is inexpensive vs. the
> labor of building anything.

I'm not sure what "already built" means other than the obvious thing. 
But why wouldn't other boards be "already built"?  Are you saying this 
comes in a box?  Does that include the relay boards?  If you need to put 
the relay boards in another box, why not put it all in one box?

> We will be using other aspects, such as the analog inputs, RTC,
> and the touch screen.

Analog inputs are not uncommon on CPU boards   along with RTC and touch 
screen.  In fact, all this is extremely common.

> If you are aware of a different unit (....no matter if it's
> called a PLC or an X-15) that does what this one does, plus a
> wired Ethernet port, suggestions welcome.

You can get a Raspberry Pi for a number between $5 and $35 including a 
40 pin header with serial, SPI and I2C ports along with 3.3 volt GP I/O. 
  It is easy to find an analog input module to plug into the header and 
it is easy to find RTC and touch screen LCDs.  I don't know just how the 
unit you are looking at is packaged.  But if you are happy with it, go 
for it.  I'm just saying that there is a lot on the PLC that you aren't 
using.  In fact, all the stuff that you aren't using is what makes a 
typical PLC different from a CPU card.  So it just seemed a bit out of 
line.  But the price for this PLC is pretty good actually.  My brother 
is using one that is a *lot* more money.

-- 

Rick C

Thread

Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-25 02:46 +0000
  Re: Output boards, SPI vs I2C krw@notreal.com - 2017-03-24 23:25 -0400
    Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-26 04:13 +0000
  Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-03-25 14:04 -0400
    Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-26 04:11 +0000
      Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-03-26 02:37 -0400
        Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-26 14:41 +0000
          Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-03-26 12:47 -0400
            Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-26 19:49 +0000
              Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-03-27 10:49 -0400
                Re: Output boards, SPI vs I2C Jasen Betts <jasen@xnet.co.nz> - 2017-03-27 18:41 +0000
                Re: Output boards, SPI vs I2C Martin Riddle <martin_ridd@verizon.net> - 2017-03-27 19:07 -0400
                Re: Output boards, SPI vs I2C Jasen Betts <jasen@xnet.co.nz> - 2017-03-28 08:03 +0000
                Re: Output boards, SPI vs I2C Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-28 10:44 -0400
                Re: Output boards, SPI vs I2C Jasen Betts <jasen@xnet.co.nz> - 2017-03-28 18:59 +0000
                Re: Output boards, SPI vs I2C Martin Riddle <martin_rid@verizon.net> - 2017-03-28 15:37 -0400
                Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-04-03 17:49 +0000
                Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-04-03 15:18 -0400
                Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-04-04 02:59 +0000
                Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-04-04 00:54 -0400
                Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-28 05:08 +0000
                Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-03-28 02:16 -0400
  Re: Output boards, SPI vs I2C Martin Riddle <martin_ridd@verizon.net> - 2017-03-27 19:03 -0400
    Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-28 03:28 +0000
      Re: Output boards, SPI vs I2C rickman <gnuarm@gmail.com> - 2017-03-28 00:38 -0400
        Re: Output boards, SPI vs I2C David Lesher <wb8foz@panix.com> - 2017-03-28 14:47 +0000

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