Logix5000 Math Question

Chado613

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C

Join Date

Mar 2005

Location

Kingston

Posts

79

• Feb 10, 2015

• #1

Hello guys,

Im troubleshooting some structured text logic in 5000 in structured text, I came upon this and am not sure what is happening:

ratio := 2.71828 ** ( 0.0 - FunctionBlock_Cycle_Time / 60000.0 / pranalog.lag );

Any help is appreciated

 

TConnolly

Lifetime Supporting Member

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Apr 2005

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Salt Lake City

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6,152

• Feb 10, 2015

• #2

The ** operator is the exponent.

ratio := 2.71828^{( 0.0 - FunctionBlock_Cycle_Time / 60000.0 / pranalog.lag )}

 

Sergei Troizky

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S

Join Date

Oct 2004

Location

Montreal

Posts

736

• Feb 10, 2015

• #3

You have to figure out yourself, what is the pranalog.lag, and what is the physical meaning of the result.

 

xzen

Lifetime Supporting Member

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Jun 2006

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Oslo

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97

• Feb 10, 2015

• #4

This is a (natural) exponential function.
2.71828 is Euler's number e wich is put in the power of some argument expressed inside the parenthesis. The double asterisk ** is the operator "to the power of" in structured text.