Making measuring insensitive to 5% of the input

juzeko · Sep 13, 2009

I have one problem regarding the simatic s7-300 and step 7. I have 4 analog inputs of 0-20mA by which i am measuring the gas flow. When the valve is closed I still get some current so I need to make it insensitive to 5% of the input. Any elegant ideas, is there any block in library for it?
THX!

L D[AR2P#0.0] · Sep 13, 2009

Here's a block that you can use to pre-process your PIW value and then pass the output on to FC105 via a temp variable.

Code:

FUNCTION FC 3 : VOID
TITLE =
VERSION : 0.1

VAR_INPUT
  iPIWValue : INT ; 
  iPerCentToIgnore : INT ; 
END_VAR
VAR_OUTPUT
  iPIWDesensitised : INT ; 
END_VAR
BEGIN
NETWORK
TITLE =
// If iPIWValue > (27648 * iPercenttoIgnore/100.0)
// then
//   iPIWDesensitised:=iPIWValue
// Else
//   iPIWDesensitised:=0
// Endif
//..
      L     #iPerCentToIgnore; 
      ITD   ; 
      DTR   ; 
      L     2.764800e+002; // 27648/100
      *R    ; 
      RND   ; 
      L     #iPIWValue; 
      <I    ; 
      JC    ok; 
      L     0; 
ok:   T     #iPIWDesensitised; 
      SET   ; 
      SAVE  ; 
END_FUNCTION

juzeko · Sep 13, 2009

thank you

Making measuring insensitive to 5% of the input

juzeko

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L D[AR2P#0.0]

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juzeko

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