Re: [foxboro] client server

Interesting thread.

If I had my druthers, I would say, in order, (1) ASCII flat files, (2) SQL 
or XML (kind of a tie there), and (3) Excel.  ASCII flat files are simple 
and cross-platform.  XML is cross-platform, but not so simple, though 
open-source parsers in just about every language maybe tame the XML beast 
a bit.  And since you get your schema (somewhat) and your data in one 
shot, it may be better for representing complex or varying data models.


SQL sounds good on paper, but if it is M$ SQL Server, and I'm running a 
processing script on a Unix box (AW51 or something else), how do I get to 
it?  Maybe there are Unix ODBC drivers for SQL Server, but it can't be 
common.  [There are some JDBC drivers, but it is silly for me to learn 
Java just for that.]  And Excel?  It's a wonderful tool for certain 
things, but not text processing (VBA regex library notwithstanding).  It 
would be an extra step for me to get into Excel and export the file as 
delimited ASCII, which I would do almost every time.


Maybe I'm not seeing the whole picture, but the only big advantage I see 
to knowing how Foxboro stores its data internally is so you can fix it 
yourself when it breaks.  Better yet, if you could reconstruct all the 
block configuration from the checkpoint file, it is mostly a moot issue; 
your sequence (and PLB?) code are ASCII and can be saved separately, and 
while your control strategy diagrams and other eye candy are important for 
documentation, they are not essential to getting a plant back up and 
running.  And since that is the checkpoint, there would be less chance for 
breakage and no catastrophic loss of synchronization.  That "one true 
database - the checkpoint" thing is sounding better all the time :)


As a side note, I was troubleshooting an Allen-Bradley CompactLogix 
yesterday.  We did not have the original program or database from the 
package unit vendor.  I got online with the processor and uploaded the 
entire program, complete with variable names.  The only thing missing was 
the comments.  With the excellent cross-referencing tools in their 
programming software, we were able to get our problems resolved without 
access to the original configuration database (their "workfile") at all.


Corey Clingo
BASF Corporation




 
 
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
 
foxboro mailing list:             http://www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave

Other related posts: