Re: Industrial I/O

I generally agree with Kevin, but you might also want to consider using the
serial ports (before they and the parallel port go away and you have to use
USB for everything). The simplest approach for a few I/O lines is to use
the serial control and status lines with transistor/opto drivers, a la the
parallel port approach but without the need for special DLLs.

I often use serial I/O for my applications, mapping many ports that are
remoted by "ethernet to serial" convertors. This allows the use of
fiberoptics for noisy environments, accomodates long distances and provides
flexible wide-area distribution of the I/O. Thus, remote terminal units can
be driven from a single port or 16+ ports. Many remote ethernet to serial
convertors also support RS-485 without an external adaptor. But, these
adaptors are not cheap. The integrated Opto 22 approach is probably better
for a any large amount of I/O that must have industrial reliability.

Also consider using a simple ASCII control protocol and a cheap ($2 to $6)
microcontroller for the remote terminal units. Many controllers have a
serial UART and enough I/O lines to handle 10 to 20 I/O devices (e.g., Atmel
2051, 8252, 2313, 8515 and most of the PIC uPs).

For quick home-brew jobs, Radio Shack sells an opto-isolated 110 VAC solid
state relay that handles several amps (not cheap, but simple to acquire.)
Weeder electronics also sells a line of serial I/O equipment but it is more
toward the "hobbyist" end than the Grayhill or Opto 22 lines.

-----Original Message-----
From: Appert, Kevin [mailto:kevin.appert_at_lmco.com]
Sent: Sunday, December 09, 2001 12:52 PM
To: 'sftalk_at_forth.com'
Subject: [sftalk] Re: Industrial I/O

As a couple of others have pointed out, there are lots of answers to this.
You need to narrow it down a bit.
1) how many input points, output points? How much current to be switched?
2) card in the PC or external intreface (serial, USB, Ethernet...)
3) how much money do you have? Forth Inc will build the whole thing for
you at reasonable prices. (I don't work for Forth Inc.)
4) any legacy systems to talk to?
5) Other details? Lots of EMI? Is the whole thing under water? Is the oil
well on fire at the time?

      Several companies make PC plug in cards that drive solid state relays
like the Opto-22 (the most popular ones) line or Crydom. There are boards
you can stuff with groups of them and you can daisy-chain the boards. They
are generally limited to switching 2 Amperes per channel.
Here is a starting point:
http://www.opto22.com/

It sounds so much more techno-industrial in German:
http://www.opto22.de/

        To many hits to see :
http://www.altavista.com/sites/search/web?q=opto.22+&pg=q&kl=XX&search=Searc
h

      A few of companies make RS485 modules (easily driven from an RS232
port with a little converter) which will drive 110 (220, 440 ... ) switches.
There are DIN-rail mounted ones and ones you can just hold down with duct
tape.

     A new trend is Ethernet (like 10-base-T mostly) nodes. There are a
whole bunch of these also. (Opto 22 has a nice looking line).

You said "Minimalist" so try this:
   1) put a buffer transistor or two on your printer port and run it into a
opto-solid state relay(s) and/or opto-isolators. (Black Box and a couple of
other firms sell switches which will run directly from serial ports or
printer ports)
   2) use Swift-Forth's DLL to convince Windows to let you talk to the
registers and do I/O directly.

I don't recommend X-10 type systems for industrial use. You don't want to
risk things going on or off at the wrong time.

> -----Original Message-----
> From: Jerry Avins [SMTP:jya_at_ieee.org]
> Sent: Saturday, December 08, 2001 7:15 AM
> To: sftalk_at_forth.com
> Subject: [sftalk] Re: Industrial I/O
>
>
> Allen Anway wrote:
> >
> > In my work of factory automation, I have to sense 110VAC inputs and run
> 110VAC outputs.
> >
> > Question (a): Does someone sell a minimalist I/O that could be operated
> with SwiftForth as the brain?
> >
> > Question (b): Does someone sell a minimalist system complete of itself?
> >
> > Thank you for any assistance you can offer --- Allen Anway
> >
> > ----------------------------------------------------------------------
> > sftalk_at_forth.com The SwiftForth programming discussion email list
> > To unsubscribe, send subject "unsubscribe sftalk" to listar_at_forth.com
> > For help with listar commands, send subject "help" to listar_at_forth.com
> > Archives are located at http://www.forth.com/sftalk -- check them out!
> > Search the archives! Visit http://www.forth.com/search for details.
>
> You don't mention a current requirement. Crydom makes solid-state relays
> that interface TTL-level signals to AC power, and boards to hold
> collections of them. National Instruments makes digital I/O daughter
> boards, and provides them with software drivers. They probably sell them
> connected by a cable to a (Crydom?) external board. You may be able to
> get all the digital I/O you need from a modern printer port. Look at
> http://www.fapo.com
>
> Jerry
>
> www.crydom.com/ www.natinst.com/
> --
> Engineering is the art of making what you want from things you can get.
> -----------------------------------------------------------------------
> ----------------------------------------------------------------------
> sftalk_at_forth.com The SwiftForth programming discussion email list
> To unsubscribe, send subject "unsubscribe sftalk" to listar_at_forth.com
> For help with listar commands, send subject "help" to listar_at_forth.com
> Archives are located at http://www.forth.com/sftalk -- check them out!
> Search the archives! Visit http://www.forth.com/search for details.
----------------------------------------------------------------------
sftalk_at_forth.com The SwiftForth programming discussion email list
To unsubscribe, send subject "unsubscribe sftalk" to listar_at_forth.com
For help with listar commands, send subject "help" to listar_at_forth.com
Archives are located at http://www.forth.com/sftalk -- check them out!
Search the archives! Visit http://www.forth.com/search for details.
----------------------------------------------------------------------
sftalk_at_forth.com The SwiftForth programming discussion email list
To unsubscribe, send subject "unsubscribe sftalk" to listar_at_forth.com
For help with listar commands, send subject "help" to listar_at_forth.com
Archives are located at http://www.forth.com/sftalk -- check them out!
Search the archives! Visit http://www.forth.com/search for details.
Received on Mon Dec 10 2001 - 10:09:13 PST