Bürkert 8619 multiCELL WM AC, Operating Instructions Manual

Page: 89 / 194

8.10.12 Configuring an arithmetic function
A+B
A–B
A*B
A/B
(A/B)[%]
(1–A/B)[%]
(A/B–1)[%]
MATH
B
Fx : A+B
A–B
A*B
A/B
(A/B)[%]
(1–A/B)[%]
(A/B–1)[%]
α
op
1
A op
2
β
op
3
B op
4
γ
A
Fig. 55 : Arithmetic functions
The functional block is used to calculate the image using one of the arithmetic functions available for 2 variables,
A and B, selected from the process variables available.
Variables A and/or B may be:
• a process variable (see section 8.16 Process inputs or values or process value network)
• a constant
or
• the result of a function already used (see section 5.6.1, page 19)
By using the operators "+" or "-", A and B must be of the same kind and have the same units.
Function Calculation made
A+B Sum of 2 variables, A and B
A–B Subtraction between the 2 variables, A and B
A*B Product between 2 variables, A and B
No automatic adjustment of the units!
▶
For the "*" (multiplication), make sure the unit of the final result
is coherent.
A/B Ratio between the 2 variables, A and B
A/B[%] Passage rate
(1 – A/B)[%] Rejection rate
(A/B – 1)[%] Deviation rate
MATH Equation
α
op
1
A op
2
β
op
3
B op
4
γ
A or B may be the result of another function.
α
,
β
and
γ
are constants.
The arithmetic operations op
1
, op
2
, op
3
, op
4
follow the usual
mathematical order (operation order from the left to the right if "*" and
"/" in the same equation)
Example: (
α
*A)+(
β
*B)+
γ
No automatic adjustment of the units!
▶
For the operations "+" (addition) or "–" (subtraction), make
sure all the items have the same units.
▶
For the operations "*" (multiplication) or "/" (division), make
sure the unit of the final result is coherent.
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Adjustmentandcommissioning
Type 8619
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