Re: [foxboro] FBM232 and AB ControlLogix

I concur with David Johnson that the FDSI provides good integration with 
ControlLogix but there is one item that has caused us extra work.
We are currently configuring six FCP270/FBM233 redundant pairs to replace 
nine Integrator 30s that have been in service for 12 to 14 years. 
Initially the integrators talked to  PLC3 processors but early in 2002 we 
started migrating to CL.  At that time the Integrator 30s stayed and we 
moved communications to KFC cards on ControlNet.

Over the many  years using the Integrator 30s, we utilized the MCOUT block 
extensively.  When these blocks were locked in manual they gave PERFECT 
bidirectional control at the bit level.  This was a convenient feature 
that we used as a manual control bit for just about every valve and motor 
in our plant; we didn't have any digital devices wired directly to the 
Foxboro.  It was a neat, non-OPC compliant feature: changes within each 16 
bit integer originating from either the PLC or the Foxboro were reconciled 
and updated to both platforms, all in the same I/O scan. 

A little over two years ago we started testing an FDSI and made Foxboro 
aware that the PAKOUT block didn't mimic this bidirectional capability. 
For short periods of time the PAKOUT appears to offer bidirectional 
control but eventually any bit level change logged from the PLC side is 
undone when a bit level change is detected from the Foxboro side.  Believe 
me, whacky things can happen if you are not aware of this and expect it to 
work like the old MCOUT block. 

We issued a CAR and after a lengthy pause we were told the functionality 
could not be added to the PAKOUT block.  As you can imagine this made 
migration a chore as we were forced to change control strategy for 
thousands of rungs.   Single BOUT blocks can be used, but with the tag 
limitations, putting in 16 BOUTS to replace every MCOUT wasn't really an 
option for our site. 

In the grand scheme of things, it was just another bump in the road, but 
anyone who has capitalized on the bidirectional capability of the MCOUT 
block needs to plan ahead.


Russ Kaiser

Control System Engineer
Corn Products - Winston-Salem, NC
Office: (336) 785-8826
Cell: (336) 558-3355



From:
David Johnson <drjohn@xxxxxxxxxx>
To:
foxboro@xxxxxxxxxxxxx
Date:
05/26/2009 06:09 PM
Subject:
Re: [foxboro] FBM232 and AB ControLogix
Sent by:
foxboro-bounce@xxxxxxxxxxxxx



Here's a ringing customer endorsement, (OK ringing might be a little 
strong and I'm not a customer but an integrator, close enough.)

1) The FBM232 supports ethernet/IP communications with the CLX based on 
tags.
    Supports up to 4000 tags ( I think that's right)
2) It is really fast compared to the old serial KF2 or KFC style 
communications.
3) It is pretty robust.  *There were some problems early on, but they 
work pretty much as advertised these days.
4) Fault tolerant comms work (but be sure to check configuration and test)

The only drawbacks we have seen with these are the lack of support 
for User Defined Types {UDTs] in tags, and some of the old tricks 
like mapping one memory location to multiple tags.

Also it would have been nice if the PAKINs had individually 
accessible bits for use on displays like MCINs.  Either you can 
bitmask every bit you wish to display, or map the PAKIN to an MCIN to 
show them on Foxview.   (ICC conections are not affected since they 
support the C:B.P.B1...B32 extensions.)

Overall a nice product and one we use a lot.

Regards,
David






 
 
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