Re: [foxboro] Hard-coding the block inhibit parameters

  • From: Corey R Clingo <corey.clingo@xxxxxxxx>
  • To: foxboro@xxxxxxxxxxxxx
  • Date: Fri, 22 Jun 2007 11:17:25 -0500

You may know this already, and/or it may not be your problem, but I found 
that connecting .INHALM does not prevent inhibit changes using .INHIB. 
Fortunately, this worked for me, since I was trying to selectively inhibit 
certain alarms based on process conditions, but did not want to remove the 
operator's ability to globally inhibit alarms on the block.

I have not had problems when connecting .INHALM with the zero bits 
remaining settable, but I have not tried any loopback connections.  Maybe 
it has to be hex (i.e., .INHB.X000 or 0X000 or whatever the syntax is), 
but I would think just .INHALM.0 would also work.


I have a similar issue on other parameters though, ones that are settable 
but not connectable.  I'm still mulling over ways to deal with that 
problem (d_edit scripts on the faceplates/details to set protection 
classes on them, sequence block "enforcers", etc.).


Corey Clingo
BASF Corporation






"Joseph M. Riccardi" <joe@xxxxxxxxxxxxx> 
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06/22/2007 10:30 AM
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[foxboro] Hard-coding the block inhibit parameters





Folks,
Based on info gleaned from this list about hard-coding block parameters
(i.e., alarm values, etc.) and the 2 block inhibit parameters (INHALM &
INHIB), we decided to try to eliminate the High Alarm function only on a
block and wanted to hard-code it so the operators could not override it.
1st of all, it was an adventure figuring out the Hex value for the INHALM
parameter (C:B.P.INHALM.0002 finally worked to inhibit the High Alarm 
only;
the 2nd lsb).  My thanks to a Matt on this list for his help.  The reason
for the confusion was because hard-coding these block inhibit parameters
only appeared to secure the block parameter when a 1 is applied; a 0 did 
not
prevent the operators from overriding the inhibit functions, nor did a 0
override an existing inhibit from the Select display.  Any explanation for
why all bits are not secured when we hard-code this parameter; only the 
high
(1) bits?  Since the INHALM parameter is one of the few Hex types, I 
assume
it is some how treated differently?

This dilemma becomes more significant as we develop plans to hard-code 
both
block inhibit parameters (0 = uninhibited) on all blocks to prevent the
operators from inhibiting block alarms (they have no access to the control
configurator).  Unless I am missing something, hard-coding this parameter
with all 0s (C:B.P.INHALM.0000) accomplished nothing, so it will not 
prevent
the operators from overriding and inhibiting (1) alarms?  Am I confused...
again?

I sincerely appreciate the help I get from this list...


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





 
 
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