I'll try to clarify.
As you know all computers are bound by CPU cycles, RAM, and I/O bandwidth.
Generally, the DI30 is limited by I/O bandwidth. The limit is about 256
bytes per second (or 128 registers per second if you prefer).
The AB-Station has DMA access to the I/O, i.e., it reads the same RAM that
the PLC is reading so I/O bandwidth is not much of a problem.
Next up is CPU Cycles.
The I/A Series control packages use floating point math as opposed to older
products which worked in integer math (counts). The older systems avoided
floating point math like the plague because it was very, very slow if you
had to do it in software.
As technology advanced, floating point co-processors (8087) appeared. As the
advance continued, some microprocessors incorporated the floating point
coprocessor onto the CPU chip.
However, the CPU used in the AB Copro board, which is the hardware portion
of the AB-Station, uses a Motorola a member of the 68K family that does not
have floating point support built-in. The Copro does (or did) offer a
Digital Signal Processing chip for high speed integer math, but it is of no
value to us.
Therefore, the AB-Station is rated at about 200 Blocks per second while the
DI30 is about 300 Blocks per second. Now, not all blocks are created equal
and if your application uses all Contact Input and Contact Output blocks (no
floating point math), the differences between the boxes are slight for block
processing, but most of our customers find the AB-Station to be somewhat
slower.
RAM is the next limit. If memory serves, the amount of RAM in the two boxes
is comparable.
Does this help?
BTW: Micro I/A is bigger (RAM) and faster (CPU) than the DI30 or AB-Station.
I/O bandwidth depends on the physical connection; however, even serial
(ABDH) throughput is better. Ethernet throughput blows the doors off the
serial line though it is not as good as DMA.
Regards,
Alex Johnson
The Foxboro Company
10707 Haddington
Houston, TX 77043
713.722.2859 (v)
713.722.2700 (sb)
713.932.0222 (f)
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
-----Original Message-----
From: Stan Brown [SMTP:[EMAIL PROTECTED]]
Sent: Wednesday, May 03, 2000 11:23 AM
To: [EMAIL PROTECTED]
Subject: Re: Integrator 30's vs. AB Stations
On Wed May 3 10:33:39 2000 Johnson,Alex wrote...
>
>To integrate AB PLCs, we have the following options:
>
>ABI30s - Serial I/F to ABDH, slowest option, optionally FT. No PLC
>Integration blocks. No PID family blocks.
>AB Station - PLC 5 only, better diagnostics, no redundancy, faster
I/O
>interface, but blocks processes is no better than DI30s overall.
Has the PLC
>integration blocks in V6.2. Has Sequence Blocks. No PID family
blocks.
>Micro I/A - Faster than DI30 (about a CP40), more physical network
>configuration options (E'net or serial), Full I/A Series Block Set
(PID, PLC
>Integration, and Sequence)
>AW-I - The AW integrator uses an AW50 or AW70 to connect to the
PLC.
>Functionally, it is similar to Micro I/A, but holds more blocks.
>
Thanks, see my other response on this thread, please.
Could you explain what you mean by fatser I/O interface? Do
you mean
faster scan times for a given number of points? More points
per
interface? We have run inot some limits in the use of
Integrator 30's,
amd it appears to me that the AB Station should be a much
higher
preformance interface, given that it's a mre powerfull
processor and
directly connected to the processor.
By higher preformance, I mean faster scan times for a given
number of
points, and ability to support a greater quantity of points.
We would be dealing primarliy with digital points here.
--
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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