Re: [foxboro] cascade/constraint control
- From: "Joseph M. Riccardi" <joe@xxxxxxxxxxxxx>
- To: <foxboro@xxxxxxxxxxxxx>
- Date: Tue, 23 Oct 2007 23:23:20 -0400
From memory... If you want a smooth transfer between the LC and TC, and you
want to prevent the controller not selected from winding up/down, connect
the FBK parameter of each block to the output of the SIGSEL, or OUTSEL. The
controller not selected will track the controller selected, with an off set
equal to the proportional error.
Joseph M. Riccardi, Inc.
DCS Services - Industrial Process Control
Joe@xxxxxxxxxxxxx
"To give real service you must add something that cannot be bought or
measured with money; and that is sincerity and integrity." - Donald A. Adams
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On
Behalf Of Gregory A Hurwitt
Sent: Tuesday, October 23, 2007 4:07 PM
To: foxboro@xxxxxxxxxxxxx
Subject: [foxboro] cascade/constraint control
I have a control scheme that will normally run as level-flow cascade. If
the temperature of the downstream equipment falls too low, then the flow
must be restricted. I plan to use a constraint control scheme:
+-----------+ +-----------+ +-----------+
| | | | | |
| LC | --------> | SIGSEL | --------> | FC |
| | | (low) | | |
+-----------+ +-----------+ +-----------+
^
+-----------+ |
| | |
| TC | -----------------+
| |
+-----------+
What are the recommended FBK and BCALCI connections for the LC and TC? How
do I ensure that the TC does not wind up while it is not selected?
____________________________________________________________________________
__________
Greg Hurwitt
Engineering Associate
E-Mail: gregory.hurwitt@xxxxxxxx
Postal Address:
BASF Corporation
602 Copper Road
Freeport, TX 77541
USA
BASF - The Chemical Company
_______________________________________________________________________
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: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
_______________________________________________________________________
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: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
Other related posts:
