Rockwell Automation 5370-CMPK Color CVIM Module MATH-PAK - Manual (Page 44)

Chapter 4
Defining Formulas
4–29
When the value of GAGE2.3 is positive, the conditional expression
(GAGE2.3 < 0) equals 0, so that 0 is added to the arctangent value.
Note that the previous example formula does not provide positive angular
measurements for arctangent values between 0
°
and –90
°
(see Figure 4.15),
which would correspond to positive angular measurements from 270
°
to
360
°
. In order to supply values from 270
°
to 360
°
rather than values 0
°
to
–90
°
, you could redefine the formula to also conditionally add 360:
ARC TAN(GAGE2 / GAGE2.3) + 180 *(GAGE2.3 < 0) + 360 * (GAGE2.3>0 AND GAGE2 < 0)
If the value of GAGE2.3 is positive (meaning the object is to the right of
the workpiece center), and the value of GAGE2 is negative (meaning the
object is above the workpiece center), the conditional / logical expression
(GAGE2.3>0 AND GAGE2 < 0) equals 1. The value 1 is multiplied by
360 and added to the arctangent value. As shown in Figure 4.15, the operand
GAGE2.3 would be a positive value, and the value of GAGE2 is negative,
so that 360 would be added to the arctangent value –55, for a formula result
of 305.
Figure 4.15 Example application: Finding angular results greater than 270
°
X
q
q
= –55
°
(arctangent
measure of the
object relative to the
workpiece center)
Angle of object, relative to
workpiece center (305
°
)
Statistical Operators
This section discusses the statistical operators, which include AVG (average),
MAX (maximum), MED (median), MIN (minimum), MOD (mode), and VAR
(variance).
Format/Usage: To use any of the statistical operators, enter the respective
operator
(AVG, MED, etc. ) – which includes the open parenthesis “(” – then
enter the operand or expression, and then enter the close parenthesis “).”
The statistical operators can be used with 1) single operands, 2) operator/
operand expressions, such as arithmetic expressions, 3) parenthetical