Re: [foxboro] NONLOP function

Jaime

I use this to control the level of a tank, that has minor upsets in level
every 15 minutes when filters are backwashed.
When the backwash starts, the tank level starts to drop, and without the
NLOPT, the Prop. action would open the feed valve, which causes a swing in
the feed chemicals (not desirable). This configuration allows the
controller to (almost) ignore the backwash upsets.

The controller is configured as follows: NONLOP = 1, HZONE = 0.2, LZONE =
0.2, and KZONE = 0.1 (PBAND = 100).

When the spt deviation is between +0.2, and - 0.2, the controller gain is
(1.0 X 0.1) = 0.1 (1,000% PB).
If the error is larger than + or - 0.2, the gain is 1 (100% PB).

It is confusing because Foxboro uses PB for setting controller gain, and
the KZONE is a gain factor, so you must convert PB to gain to calculate the
effect of your chosen KZONE.

      -Regards, Brian Bates.




                                                                                
                                              
                      "Jaime Claramunt                                          
                                              
                      R. (Inforsa)"            To:       foxboro@xxxxxxxxxxxxx  
                                              
                      <jclaramunt@infor        cc:                              
                                              
                      sa.cmpc.cl>              Subject:  [foxboro] NONLOP 
function                                            
                      Sent by:                                                  
                                              
                      foxboro-bounce@fr                                         
                                              
                      eelists.org                                               
                                              
                                                                                
                                              
                                                                                
                                              
                      01/19/2005 11:24                                          
                                              
                      AM                                                        
                                              
                      Please respond to                                         
                                              
                      foxboro                                                   
                                              
                                                                                
                                              
                                                                                
                                              




Hi List,

Does anybody knows how to work with NONLOP option on PIDXE block ?
Manuals are a little bit confusing...about HZONE and LZONE (percent of
span,
absolute value, of error,)
Do you have an actual case ?

Thx
Jaime Claramunt
INFORSA paper mill






 
 
_______________________________________________________________________
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: