Following this discussion, I have noted several things.
1. DH+ is basically, for all intents and purposes, Token Ring (56K).
Through a 1770-KF2 CAM (modem) to RS232 Communications to the INT30 to
the node. Bad loss of bandwidth.
2. Micro I/A performs a ethernet connection to the I/A system with
better processor power and bandwidth, therefore throughput.
Questions:
1. What is the transfer rate through Micro I/A? (10MB)?
2. Why cannot we get an FDGW,MDGW or INT30 etc. with an ethernet
adaptor built in? Something that is fault tolerant that will work
with AB, Modicon, etc. ethernet networks. (Please pardon my ignorance
if I don't see the big deal here) Micro I/A does it.
### Comment: Even if you don't have redundant PLC's, if those PLC's
are networked together ( as in for remote programming capabilities)
you would still want to see all of them that are up(- the one that
"failed") with redundant ethernet and adaptors to the I/A system?
**** Whew! Out of finger breath there!***
3. For single PLC applications, why not ethernet communications to the
I/A since most new PLC's support ethernet, and why, for the 56K DH+
networks, the need to go RS232 before getting to I/A.
Thanks for everyone's patience. I have DH+ through 1770-KF2 cam to INT
30 on AB SLC500 PLC's. Modicon GW from 984's.
Daren Bishop
Process Engineer
Ameripol/Synpol Corp.
[EMAIL PROTECTED]
______________________________ Reply Separator _________________________________
Subject: Re: Integrator 30's vs. AB Stations
Author: "Foxboro DCS Mail List" <[EMAIL PROTECTED]> at
INTERNET-MAIL
Date: 5/3/00 4:46 PM
On Wed May 3 16:01:16 2000 Johnson,Alex wrote...
>
>Stan,
>
>
>Re: Options
>Are you dead set against Micro I/A for AB integration?
No, we are not oposed to this solutin, but I for one am totaly
unfamiliar with it. Does it integrate well into a sytesm based up 51
serries AP/QP/AW's, with the orignal I?A I/O structure, and AB PLC5's?
>
>It has Ethernet support, it's faster than a CP30 (almost a 40), it has the
>full block set, it costs less, ...
>
>
>Frankly, I can't see a reason to use a DI30 unless you need fault-tolerant
>electronics.
There is a desire for that, although myself I don't think it is
imprtant based upon:
1. There is still only a single PLC (as in no PLC edundancy).
2. The Fooxboro hardware has a long history of reliabilty in our mill.
>
>Re: AW-I
>
>Yes, the AW-I if not running would cut you off from the PLCs. However, it is
>suitable for a number of uses.
I would find this troubling. At presnt I can reboot (or shutdown for
backup) any AP/WP/AW on any node and, as long as I don't have any other
abnormal occurences, it is transparent to controling the process.
If I had a Sun workstation that was a critical part of the
communications path to my PLC's I could not do this. This is
unfortunate, because this should be a huge preformance win over any
other solution.
I think taht a system using to Sun's could be designed to provied
redundant commuctioan paths to/from the PLC. IMHO tyhis would be the
ideal solution. I will admit it would be a bit costly, but I think I
could justify the cost for teh preformance, and reliability.
--
Stan Brown [EMAIL PROTECTED] 843-745-3154
Charleston SC.
--
Windows 98: n.
useless extension to a minor patch release for 32-bit extensions and
a graphical shell for a 16-bit patch to an 8-bit operating system
originally coded for a 4-bit microprocessor, written by a 2-bit
company that can't stand for 1 bit of competition.
-
(c) 2000 Stan Brown. Redistribution via the Microsoft Network is prohibited.
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